Engine Mechanical - 8.1l Chevrolet Cab & Chassis Silverado 3500

Fastener Tightening Specifications

Fastener Tightening Specifications

Engine Mechanical Specifications

Engine Mechanical Specifications

Sealers, Adhesives, and Lubricants

Sealers, Adhesives, and Lubricants

Scheme 117

Scheme 118

Scheme 119

Scheme 120

Scheme 121

Scheme 122

Scheme 123

Scheme 124

The engine identification number is located in 3 locations. There are labels on the front of the right rocker arm cover (1), the rear of the left rocker arm cover (2), and the right side of the engine oil pan (3). The engine identification number is used to track and identify the engine prior to installation in a vehicle.

The vehicle identification number (VIN) derivative is located on the left rear side of the engine block and is a 9 digit number stamped or laser etched onto the engine at the vehicle assembly plant. If reading the identification number from the left, the following information can be obtained

1. The first digit identifies the division.
2. The second digit identifies the model year.
3. The third digit identifies the assembly plant.
4. The fourth through ninth digits are the last 6 digits of the VIN.

Diagnostic Starting Point - Engine Mechanical

Begin the system diagnosis by reviewing the Disassembled Views , Engine Component Description , Lubrication Description , New Product Information , and the . Reviewing the description and operation information will help you determine the correct symptom diagnostic procedure when a malfunction exists. Reviewing the description and operation information will also help you determine if the condition described by the customer is normal operation. Refer to Symptoms - Engine Mechanical in order to identify the correct procedure for diagnosing the system and where the procedure is located.

Strategy Based Diagnostics

1. Perform a «Diagnostic System Check - Vehicle»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/oem-general-information/#vehicle-diagnostic-information__diagnostic-system-check-vehicle) before using the symptom tables, if applicable.
2. Review the system operations in order to familiarize yourself with the system functions. Refer to «Disassembled Views»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) , «Engine Component Description»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) , , «Lubrication Description»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) and «New Product Information»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__new-product-information) .

All diagnosis on a vehicle should follow a logical process. Strategy based diagnostics is a uniform approach for repairing all systems. The diagnostic flow may always be used in order to resolve a system condition. The diagnostic flow is the place to start when repairs are necessary. For a detailed explanation, refer to Strategy Based Diagnosis .

Visual/Physical Inspection

1. Inspect for aftermarket devices which could affect the operation of the engine. Refer to «Checking Aftermarket Accessories»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/ignition-switchsteering-lock/#wiring-systems-and-power-management-troubleshooting-diagnosis__checking-aftermarket-accessories) .
2. Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.
3. Inspect for the correct oil level, proper oil viscosity, and correct filter application.
4. Verify the exact operating conditions under which the condition exists. Note factors such as engine RPM, ambient temperature, engine temperature, amount of engine warm-up time, and other specifics.
5. Compare the engine sounds, if applicable, to a known good engine and ensure you are not trying to correct a normal condition.

Intermittent

Test the vehicle under the same conditions that the customer reported in order to verify the system is operating properly.

Symptom List

Refer to a symptom diagnostic procedure from the following list in order to diagnose the symptom

1. «Base Engine Misfire without Internal Engine Noises»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__base-engine-misfire-without-internal-engine)
2. «Base Engine Misfire with Abnormal Internal Lower Engine Noises»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__base-engine-misfire-with-abnormal-internal)
3. «Base Engine Misfire with Abnormal Valve Train Noise»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__base-engine-misfire-with-abnormal-valve)
4. «Base Engine Misfire with Coolant Consumption»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__base-engine-misfire-with-coolant-consumption)
5. «Base Engine Misfire with Excessive Oil Consumption»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__base-engine-misfire-with-excessive-oil)
6. «Engine Noise on Start-Up, but Only Lasting a Few Seconds»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__engine-noise-on-start-up-but-only)
7. «Upper Engine Noise, Regardless of Engine Speed»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__upper-engine-noise-regardless-of-engine)
8. «Lower Engine Noise, Regardless of Engine Speed»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__lower-engine-noise-regardless-of-engine)
9. «Engine Noise Under Load»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__engine-noise-under-load)
10. «Engine Will Not Crank - Crankshaft Will Not Rotate»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__engine-will-not-crank-crankshaft)
11. «Coolant in Combustion Chamber»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__coolant-in-combustion-chamber)
12. «Coolant in Engine Oil»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__coolant-in-engine-oil)
13. «Engine Compression Test»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__engine-compression-test)
14. «Cylinder Leakage Test»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__cylinder-leakage-test)
15. «Oil Consumption Diagnosis»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__oil-consumption-diagnosis)
16. «Oil Pressure Diagnosis and Testing»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__oil-pressure-diagnosis-and-testing)
17. «Drive Belt Chirping, Squeal, and Whine Diagnosis»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l)
18. «Drive Belt Rumbling and Vibration Diagnosis»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l)
19. «Drive Belt Falls Off and Excessive Wear Diagnosis»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l)

Base Engine Misfire without Internal Engine Noises

Base Engine Misfire without Internal Engine Noises

Base Engine Misfire with Abnormal Internal Lower Engine Noises

Base Engine Misfire with Abnormal Internal Lower Engine Noises

Base Engine Misfire with Abnormal Valve Train Noise

Base Engine Misfire with Abnormal Valve Train Noise

Base Engine Misfire with Coolant Consumption

Base Engine Misfire with Coolant Consumption

Base Engine Misfire with Excessive Oil Consumption

Base Engine Misfire with Excessive Oil Consumption

Engine Noise on Start-Up, but Only Lasting a Few Seconds

Engine Noise on Start-Up, but Only Lasting a Few Seconds

Upper Engine Noise, Regardless of Engine Speed

Upper Engine Noise, Regardless of Engine Speed

Lower Engine Noise, Regardless of Engine Speed

Lower Engine Noise, Regardless of Engine Speed

Engine Noise Under Load

Engine Noise Under Load

Engine Will Not Crank - Crankshaft Will Not Rotate

Engine Will Not Crank - Crankshaft Will Not Rotate

Coolant in Combustion Chamber

Coolant in Combustion Chamber

Coolant in Engine Oil

Coolant in Engine Oil

Engine Compression Test

1. Disconnect the ignition coil wire harness connector at the front of the engine on the left cylinder bank and at the rear of the engine at the right cylinder bank.
2. Disconnect the fuel injector electrical harness connector at the rear of the intake manifold.
3. Remove all spark plugs.
4. Block the throttle plate wide open.
5. Charge the battery, if the battery is not fully charged.
6. Start with the compression gage at 0, then crank the engine through 4 compression strokes, 4 puffs.
7. Make the compression test the same for each cylinder. Record the reading. The minimum compression in any 1 cylinder should not be less than 70 percent of the highest cylinder. No cylinder should read less than 690 kPa (100 psi). For example, if the highest pressure in any 1 cylinder is 1 035 kPa (150 psi), the lowest allowable pressure for any other cylinder would be 725 kPa (105 psi), (1035 x 70% = 725) (150 x 70% = 105).
8. If some cylinders have low compression, inject approximately 15 ml (1 tablespoon) of engine oil into the combustion chamber through the spark plug hole. Normal - Compression builds up quickly and evenly to the specified compression for each cylinder. Piston Rings Leaking - Compression is low on the first stroke, then compression builds up with the following strokes, but does not reach normal. Compression improves considerably when you add oil. Valves Leaking - Compression is low on the first stroke. Compression usually does not build up on the following strokes. Compression does not improve much when you add oil. If 2 adjacent cylinders have lower than normal compression, and injecting oil into the cylinders does not increase the compression, the cause may be a head gasket leaking between the 2 cylinders.

Cylinder Leakage Test

1. Disconnect the battery ground negative cable.
2. Remove the spark plugs. Refer to «Spark Plug Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/testing-diagnostics/#engine-controls-and-fuel-81l-introduction-2-of-2) .
3. Rotate the crankshaft to place the piston in the cylinder being tested at top dead center (TDC) of the compression stroke.
4. Install the J 35667-A or equivalent.
5. Apply shop air pressure to the J 35667-A and adjust according to the manufacturers instructions.
6. Record the cylinder leakage value. Cylinder leakage that exceeds 25 percent is considered excessive and may require component service. In excessive leakage situations, inspect for the following conditions: Air leakage sounds at the throttle body or air inlet hose that may indicate a worn or burnt intake valve or a broken valve spring. Air leakage sounds at the exhaust system tailpipe that may indicate a worn or burnt exhaust valve or a broken valve spring. Air leakage sounds from the crankcase, oil level indicator tube, or oil fill tube that may indicate worn piston rings, a damaged piston, a worn or scored cylinder bore, a damaged engine block, or a damaged cylinder head. Air bubbles in the cooling system may indicate a damaged cylinder head or a damaged cylinder head gasket.
7. Perform the leakage test on the remaining cylinders and record the values.

Oil Consumption Diagnosis

Excessive oil consumption, not due to leaks, is the use of greater than 0.95 liter (1 quart) of engine oil within 379 liters (100 gallons) of fuel used. However, during initial engine break-in periods 5 000-6 500 kilometers (3,000-4,000 miles) oil consumption may exceed 1.9 liters (2 quarts) or greater per 379 liters (100 gallons) of fuel used. The causes of excessive oil consumption include the following conditions

1. External oil leaks Tighten bolts and/or replace gaskets and oil seals, as necessary.
2. Incorrect oil level or improper reading of the oil level indicator With the vehicle on a level surface, allow adequate drain down time and measure for the correct oil level.
3. Improper oil viscosity Use recommended SAE viscosity for the prevailing temperatures.
4. Continuous high speed driving and/or severe usage
5. Crankcase ventilation system restrictions or malfunctioning components
6. Valve guides and/or valve stem oil seals worn, or the seal omitted Ream the guides and install oversize service valves and/or new valve stem oil seals.
7. Piston rings broken, improperly installed, worn, or not seated properly Allow adequate time for the rings to seat and replace broken or worn rings, as necessary.
8. Piston improperly installed or piston size is incorrectly selected

Oil Pressure Diagnosis and Testing

1. With the vehicle on a level surface, allow adequate drain down time, 2-3 minutes, and measure for the proper engine oil level. An overfull oil level causes aeration within the oil.
2. Add the recommended grade engine oil GM P/N 12345610, (Canadian P/N 993193), or equivalent, and fill the crankcase until the oil level measures FULL on the oil level indicator.
3. Operate the engine and verify low or no oil pressure on the vehicle oil pressure gage or oil indicator lamp. Listen for a noisy valve train or knocking noise.
4. Inspect for the following conditions: Engine oil diluted by moisture or unburned fuel mixtures Improper engine oil viscosity for the expected temperature Incorrect or faulty oil pressure gage sensor Incorrect or faulty oil pressure gage Plugged oil filter Malfunctioning oil filter bypass valve
5. Remove the oil pressure gage sensor or another engine block oil gallery plug.
6. Install an oil pressure gage and measure the engine oil pressure.
7. If the engine oil pressure is below specifications, inspect the engine for 1 or more of the following conditions: Oil pump worn or dirty Malfunctioning oil pump pressure relief valve Oil pump screen loose, plugged, or damaged Excessive bearing clearance or worn bearings Cracked, porous, or restricted oil galleries Engine block oil gallery plugs missing or incorrectly installed Broken valve lifters

Oil Leak Diagnosis

Oil Leak Diagnosis

Crankcase Ventilation System Inspection/Diagnosis

A plugged positive crankcase ventilation (PCV) pipe/passage way may cause

1. Rough idle
2. Stalling or slow idle speed
3. Oil leaks
4. Sludge in the engine

Diagnostic Aids

1. A chirping or squeal noise may be intermittent due to moisture on the drive belts or the pulleys. It may be necessary to spray a small amount of water on the drive belts in order to duplicate the customers concern. If spraying water on the drive belt duplicates the symptom, cleaning the belt pulleys may be the probable solution.
2. If the noise is intermittent, verify the accessory drive components by varying their loads making sure they are operated to their maximum capacity. An overcharged A/C system, power steering system with a pinched hose or wrong fluid, or a generator failing are suggested items to inspect.
3. A chirping, squeal or whine noise may be caused by a loose or improper installation of a body or suspension component. Other items of the vehicle may also cause the noise.
4. The drive belts will not cause a whine noise.

Test Description

The numbers below refer to the step numbers on the diagnostic table.

1. 2: The noise may not be engine related. This step is to verify that the engine is making the noise. If the engine is not making the noise do not proceed further with this table.
2. 3: The noise may be an internal engine noise. Removing the drive belts one at a time and operating the engine for a brief period will verify the noise is related to the drive belt. When removing the drive belt the water pump may not be operating and the engine may overheat. Also DTCs may set when the engine is operating with the drive belts removed.
3. 4: Inspect all drive belt pulleys for pilling. Pilling is the small balls or pills or it can be strings in the drive belt grooves from the accumulation of rubber dust.
4. 6: Misalignment of the pulleys may be caused from improper mounting of the accessory drive component, incorrect installation of the accessory drive component pulley, or the pulley bent inward or outward from a previous repair. Test for a misaligned pulley using a straight edge in the pulley grooves across two or three pulleys. If a misaligned pulley is found refer to that accessory drive component for the proper installation procedure for that pulley.
5. 10: Inspecting of the fasteners can eliminate the possibility that a wrong bolt, nut, spacer, or washer was installed.
6. 12: Inspecting the pulleys for being bent should include inspecting for a dent or other damage to the pulleys that would prevent the drive belt from not seating properly in all of the pulley grooves or on the smooth surface of a pulley when the back side of the belt is used to drive the pulley.
7. 14: This test is to verify that the drive belt tensioner operates properly. If the drive belt tensioner is not operating properly, proper belt tension may not be achieved to keep the drive belt from slipping which could cause a squeal noise.
8. 15: This test is to verify that the drive belt is not too long, which would prevent the drive belt tensioner from working properly. Also if an incorrect length drive belt was installed, it may not be routed properly and may be turning an accessory drive component in the wrong direction.
9. 16: Misalignment of the pulleys may be caused from improper mounting of the accessory drive component, incorrect installation of the accessory drive component pulley, or the pulley bent inward or outward from a previous repair. Test for a misaligned pulley using a straight edge in the pulley grooves across two or three pulleys. If a misaligned pulley is found refer to that accessory drive component for the proper installation procedure for that pulley.
10. 17: This test is to verify that the pulleys are the correct diameter or width. Using a known good vehicle compare the pulley sizes.
11. 19: Replacing the drive belt when it is not damaged or there is not excessive pilling will only be a temporary repair.

Drive Belt Chirping, Squeal, and Whine Diagnosis

The accessory drive components can have an affect on engine vibration. Vibration from the engine operating may cause a body component or another part of the vehicle to make rumbling noise. Vibration can be caused by, but not limited to the air conditioning (A/C) system over charged, the power steering system restricted or the incorrect fluid, or an extra load on the generator. To help identify an intermittent or an improper condition, vary the loads on the accessory drive components.

The drive belt may have a rumbling condition that can not be seen or felt. Sometimes replacing the drive belt may be the only repair for the symptom.

If replacing the drive belt, completing the diagnostic table, and the noise is only heard when the drive belts are installed, there might be an accessory drive component with a failure. Varying the load on the different accessory drive components may aid in identifying which component is causing the rumbling noise.

The numbers below refer to the step numbers on the diagnostic table.

1. 2: This test is to verify that the symptom is present during diagnosing. Other vehicle components may cause a similar symptom.
2. 3: This test is to verify that one of the drive belts is causing the rumbling noise or vibration. Rumbling noise may be confused with an internal engine noise due to the similarity in the description. Remove only one drive belt at a time if the vehicle has multiple drive belts. When removing the drive belts the water pump may not be operating and the engine may overheat. Also DTCs may set when the engine is operating with the drive belts removed.
3. 4: Inspecting the drive belts is to ensure that they are not causing the noise. Small cracks across the ribs of the drive belt will not cause the noise. Belt separation is identified by the plys of the belt separating and may be seen at the edge of the belt our felt as a lump in the belt.
4. 5: Small amounts of pilling is normal condition and acceptable. When the pilling is severe the drive belt does not have a smooth surface for proper operation.
5. 9: Inspecting of the fasteners can eliminate the possibility that the wrong bolt, nut, spacer, or washer was installed.
6. 11: This step should only be performed if the water pump is driven by the drive belt. Inspect the water pump shaft for being bent. Also inspect the water pump bearings for smooth operation and excessive play. Compare the water pump with a known good water pump.
7. 12: Accessory drive component brackets that are bent, cracked, or loose may put extra strain on that accessory component causing it to vibrate.

Drive Belt Rumbling and Vibration Diagnosis

If the drive belt repeatedly falls off the drive belt pulleys, this is because of pulley misalignment.

An extra load that is quickly applied on released by an accessory drive component may cause the drive belt to fall off the pulleys. Verify the accessory drive components operate properly.

If the drive belt is the incorrect length, the drive belt tensioner may not keep the proper tension on the drive belt.

Excessive wear on a drive belt is usually caused by an incorrect installation or the wrong drive belt for the application.

Minor misalignment of the drive belt pulleys will not cause excessive wear, but will probably cause the drive belt to make a noise or to fall off.

Excessive misalignment of the drive belt pulleys will cause excessive wear but may also make the drive belt fall off.

The numbers below refer to the step numbers on the diagnostic table.

1. 2: This inspection is to verify the condition of the drive belt. Damage may of occurred to the drive belt when the drive belt fell off. The drive belt may of been damaged, which caused the drive belt to fall off. Inspect the belt for cuts, tears, sections of ribs missing, or damaged belt plys.
2. 4: Misalignment of the pulleys may be caused from improper mounting of the accessory drive component, incorrect installation of the accessory drive component pulley, or the pulley bent inward or outward from a previous repair. Test for a misaligned pulley using a straight edge in the pulley grooves across two or three pulleys. If a misaligned pulley is found refer to that accessory drive component for the proper installation procedure of that pulley.
3. 5: Inspecting the pulleys for being bent should include inspecting for a dent or other damage to the pulleys that would prevent the drive belt from not seating properly in all of the pulley grooves or on the smooth surface of a pulley when the back side of the belt is used to drive the pulley.
4. 6: Accessory drive component brackets that are bent or cracked will let the drive belt fall off.
5. 7: Inspection of the fasteners can eliminate the possibility that a wrong bolt, nut, spacer, or washer was installed. Missing, loose, or the wrong fasteners may cause pulley misalignment from the bracket moving under load. Over tightening of the fasteners may cause misalignment of the accessory component bracket.
6. 13: The inspection is to verify the drive belt is correctly installed on all of the drive belt pulleys. Wear on the drive belt may be caused by mis-positioning the drive belt by one groove on a pulley.
7. 14: The installation of a drive belt that is too wide or too narrow will cause wear on the drive belt. The drive belt ribs should match all of the grooves on all of the pulleys.
8. 15: This inspection is to verify the drive belt is not contacting any parts of the engine or body while the engine is operating. There should be sufficient clearance when the drive belt accessory drive components load varies. The drive belt should not come in contact with an engine or a body component when snapping the throttle.

Drive Belt Falls Off and Excessive Wear Diagnosis

Drive Belt Tensioner Diagnosis

1. Remove the drive belt(s). Refer to «Drive Belt Replacement - Accessory»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) or «Drive Belt Replacement - Air Conditioning»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .
2. Position a hex-head socket on the belt tensioner pulley bolt head.
3. Move the drive belt tensioner through its full travel. The movement should feel smooth. There should be no binding. The tensioner should return freely.
4. If any binding is observed, replace the drive belt tensioner(s). Refer to «Drive Belt Tensioner Replacement - Accessory»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) or «Drive Belt Tensioner Replacement - Air Conditioning»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .
5. Install the drive belt(s). Refer to «Drive Belt Replacement - Accessory»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) or «Drive Belt Replacement - Air Conditioning»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .

Removal Procedure

1. Install a breaker bar with hex-head socket to the drive belt tensioner bolt.
2. Rotate the drive belt tensioner clockwise in order to relieve tension on the belt.
3. Remove the belt from the pulleys and the drive belt tensioner.
4. Slowly release the tension on the drive belt tensioner.
5. Remove the breaker bar and socket and from the drive belt tensioner bolt.
6. Clean and inspect the belt surfaces of all the pulleys.

Installation Procedure

1. Route the drive belt around all the pulleys except the idler pulley.
2. Install the breaker bar with hex-head socket to the belt tensioner bolt.
3. Rotate the belt tensioner clockwise in order to relieve the tension on the tensioner.
4. Install the drive belt under the idler pulley.
5. Slowly release the tension on the belt tensioner.
6. Remove the breaker bar and socket from the belt tensioner bolt.
7. Inspect the drive belt for proper installation and alignment.

1. Remove the accessory drive belt. Refer to «Drive Belt Replacement - Accessory»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .
2. Install a breaker bar into the air conditioning (A/C) belt tensioner adapter opening.
3. Rotate the A/C belt tensioner clockwise in order to relieve tension on the belt.
4. Remove the A/C belt from the pulleys.
5. Slowly release the tension on the A/C belt tensioner.
6. Remove the breaker bar from the A/C belt tensioner.
7. Clean and inspect the belt surfaces of all the pulleys.

1. Install the A/C belt around the crankshaft balancer.
2. Install the breaker bar into the A/C drive belt tensioner adapter opening
3. Rotate the A/C belt tensioner clockwise in order to relieve tension on the tensioner.
4. Install the A/C belt over the idler pulley.
5. Install the A/C belt around the A/C compressor pulley.
6. Slowly release the tension on the A/C belt tensioner.
7. Remove the breaker bar from the A/C belt tensioner.
8. Inspect the A/C belt for proper installation and alignment.
9. Install the accessory drive belt. Refer to «Drive Belt Replacement - Accessory»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .

1. Remove the accessory drive belt. Refer to «Drive Belt Replacement - Accessory»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .
2. Remove the drive belt tensioner bolts.
3. Remove the drive belt tensioner.

1. Install the drive belt tensioner.
2. Install the drive belt tensioner bolts. NOTE: Refer to «Fastener Notice»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/oem-general-information/#warnings-and-cautions__fastener-notice) .
3. Tighten the drive belt tensioner bolts. Tighten: Tighten the accessory drive belt tensioner bolts to 50 N.m (37 lb ft).
4. Install the accessory drive belt. Refer to «Drive Belt Replacement - Accessory»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .

1. Remove the air conditioning (A/C) drive belt. Refer to «Drive Belt Replacement - Air Conditioning»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .
2. Remove the A/C belt tensioner bolts.
3. Remove the A/C belt tensioner.

1. Install the A/C belt tensioner.
2. Install the A/C belt tensioner bolts. Tighten: Tighten the bolts to 50 N.m (37 lb ft).
3. Install the A/C drive belt. Refer to «Drive Belt Replacement - Air Conditioning»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .

1. Loosen the drive belt idler pulley bolt.
2. Remove the accessory drive belt. Refer to «Drive Belt Replacement - Accessory»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .
3. Remove the drive belt idler pulley.

1. Install the drive belt idler pulley and bolt to the generator bracket. Snug the bolt finger tight.
2. Install the accessory drive belt. Refer to «Drive Belt Replacement - Accessory»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) . Tighten: Tighten the drive belt idler pulley bolt to 50 N.m (37 lb ft).

Engine Mount Inspection

Note. Broken or deteriorated mounts can cause misalignment and destruction of certain drive train components. When a single mount breaks, the remaining mounts are subjected to abnormally high stresses.

Note. When raising or supporting the engine for any reason, do not use a jack under the oil pan, any sheet metal, or the crankshaft pulley. Due to the small clearance between the oil pan and the oil pump screen, jacking against the oil pan may cause the pan to be bent against the pump screen. This will result in a damaged oil pickup unit.

1. Measure the engine movement at the engine mount in order to check for damage to the rubber portions of the mount. Apply the park brake. Start the engine. Firmly apply and hold the primary brakes. Have an assistant stand to the side of the vehicle in order to observe for engine movement. Slightly load the engine, shifting from drive to reverse a few times If the engine moves more than 24 mm (0.945 in) from the at rest position, in either direction, check for loose engine mount bolts.
2. If the engine mount bolt torque is within specifications, check the condition of the engine mount.
3. Replace the engine mount if any of the following conditions exist: Heat check cracks cover the rubber cushion surface. The rubber cushion is separated from the metal plate of the mount. There is a split through the rubber cushion.

Note. When raising or supporting the engine for any reason, do not use a jack under the oil pan, any sheet metal, or the crankshaft pulley. Due to the small clearance between the oil pan and the oil pump screen, jacking against the oil pan may cause the pan to be bent against the pump screen. This will result in a damaged oil pickup unit.

1. If vehicle is a 2-wheel drive (2WD), raise the vehicle to a height to work through the front wheelhouse opening.
2. If vehicle is a 4-wheel drive (4WD), raise the vehicle in order to remove the front tires and wheels.
3. Remove the left front tire and wheel. Refer to «Tire and Wheel Removal and Installation»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/wheel-tire-system/#tires-and-wheels__tire-and-wheel-removal-and-installation) .
4. Remove the wheelhouse inner panel push pin retainers (2).
5. Remove the wheelhouse inner panel (1).
6. Working through the wheelhouse opening, remove the engine mount heat shield bolts.
7. Remove the engine mount heat shield.
8. Remove the engine mount-to-engine mount bracket bolt.
9. If equipped, remove the oil pan skid plate bolts and plate.
10. Remove the engine shield bolts and shield.
11. Raise the engine with a suitable jack in order to remove the engine mount and bracket.
12. Remove the engine mount-to-engine bolts.
13. Remove the engine mount.
14. Remove the engine mount bracket through bolts.
15. Remove the engine mount bracket.

1. Install the engine mount bracket onto the frame.
2. Perform the following procedure prior to installing the engine mount bracket bolts. Remove all traces of the original adhesive patch. Clean the threads of the bolt with denatured alcohol or equivalent and allow to dry. Apply threadlocker to the bolts. Refer to «Sealers, Adhesives, and Lubricants»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__sealers-adhesives-and-lubricants) for the correct part number.
3. Loosely install the engine mount bracket through bolts.
4. Position the engine mount to engine.
5. Loosely install the engine mount-to-engine bolts.
6. Tighten the engine mount bracket through bolts and engine mount-to-engine bolts. Tighten: Tighten the engine mount bracket through bolts to 75 N.m (55 lb ft). Tighten the engine mount-to-engine bolts to 50 N.m (37 lb ft).
7. Install the engine shield and bolts. Tighten: Tighten the engine shield bolts to 20 N.m (15 lb ft).
8. Lower the engine.
9. If equipped, install the oil pan skid plate and bolts. Tighten: Tighten the oil pan skid plate bolts to 20 N.m (15 lb ft).
10. Install the engine mount heat shield.
11. Install the engine mount-to-engine mount bracket bolts. Tighten: Tighten the engine mount-to-engine mount bracket bolts to 65 N.m (48 lb ft).
12. Install the wheelhouse inner panel (1).
13. Install the wheelhouse inner panel push pin retainers (2).
14. Install the left front tire and wheel. Refer to «Tire and Wheel Removal and Installation»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/wheel-tire-system/#tires-and-wheels__tire-and-wheel-removal-and-installation) .
15. Lower the vehicle.

Note. When raising or supporting the engine for any reason, do not use a jack under the oil pan, any sheet metal, or the crankshaft pulley. Due to the small clearance between the oil pan and the oil pump screen, jacking against the oil pan may cause the pan to be bent against the pump screen. This will result in a damaged oil pickup unit.

1. If vehicle is a 2-wheel drive (2WD), raise the vehicle to a height to work through the front wheelhouse opening.
2. If vehicle is a 4-wheel drive (4WD), raise the vehicle in order to remove the front tires and wheels.
3. Remove the left front tire and wheel. Refer to «Tire and Wheel Removal and Installation»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/wheel-tire-system/#tires-and-wheels__tire-and-wheel-removal-and-installation) .
4. Remove the wheelhouse inner panel push pin retainers (2).
5. Remove the wheelhouse inner panel (1).
6. Working through the wheelhouse opening, remove the engine mount heat shield bolts (left side shown, right side similar).
7. Remove the engine mount heat shield.
8. Remove the engine mount-to-engine mount bracket bolt (left side shown, right side similar).
9. Remove the oil pan skid plate bolts and plate, if equipped.
10. Remove the engine shield bolts and shield.
11. Raise the engine with a suitable jack in order to remove the engine mount and bracket.
12. Remove the engine mount-to-engine bolts (left side shown, right side similar).
13. Remove the engine mount.
14. Remove the engine mount bracket through bolts.
15. Remove the engine mount bracket.

1. Install the engine mount bracket onto the frame.
2. Perform the following procedure prior to installing the engine mount bracket bolts. Remove all traces of the original adhesive patch. Clean the threads of the bolt with denatured alcohol or equivalent and allow to dry. Apply threadlocker to the bolts. Refer to «Sealers, Adhesives, and Lubricants»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__sealers-adhesives-and-lubricants) for the correct part number.
3. Loosely install the engine mount bracket through bolts.
4. Position the engine mount to engine (left side shown, right side similar).
5. Loosely install the engine mount-to-engine bolts.
6. Tighten the engine mount bracket through bolts and engine mount-to-engine bolts. Tighten: Tighten the engine mount bracket through bolts to 75 N.m (55 lb ft). Tighten the engine mount-to-engine bolts to 50 N.m (37 lb ft).
7. Install the engine shield and bolts. Tighten: Tighten the engine shield bolts to 20 N.m (15 lb ft).
8. Lower the engine.
9. If equipped, install the oil pan skid plate and bolts. Tighten: Tighten the oil pan skid plate bolts to 20 N.m (15 lb ft).
10. Install the engine mount heat shield (left side shown, right side similar).
11. Install the engine mount-to-engine mount bracket bolts (left side shown, right side similar). Tighten: Tighten the engine mount-to-engine mount bracket bolts to 65 N.m (48 lb ft).
12. Install the wheelhouse inner panel (1).
13. Install the wheelhouse inner panel push pin retainers (2).
14. Install the left front tire and wheel. Refer to «Tire and Wheel Removal and Installation»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/wheel-tire-system/#tires-and-wheels__tire-and-wheel-removal-and-installation) .
15. Lower the vehicle.

1. Unsnap the intake manifold sight shield from the stud.
2. Remove the sight shield from the sight shield bracket.
3. Remove the sight shield bracket retainer nuts (1), if necessary.
4. Remove the sight shield bracket from the studs (2), if necessary.

1. Install the sight shield bracket to the studs (2), if necessary.
2. Install the sight shield bracket nuts (1), if necessary. Tighten: Tighten the nuts to 5 N.m (44 lb in).
3. Install the intake manifold sight shield to the bracket.
4. Snap the intake manifold sight shield onto the stud.

1. Loosen the clamps at the throttle body and air cleaner.
2. Remove the air cleaner outlet duct.
3. Unsnap the intake manifold sight shield from the stud.
4. Remove the sight shield from the bracket.
5. Remove the sight shield bracket nuts (1) and bracket, if necessary.
6. Relieve the fuel system pressure. Refer to «Fuel Pressure Relief (With CH 48027)»(ref-277873-S40865068532008012100000) or «Fuel Pressure Relief (Without CH 48027)»(ref-277873-S04692472202008012100000) .
7. Disconnect the fuel feed and return pipes. Refer to «Metal Collar Quick Connect Fitting Service»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/testing-diagnostics/#engine-controls-and-fuel-48l-53l-and-60l-introduction-2-of-2__metal-collar-quick-connect-fitting-service) .
8. Disconnect the engine harness clips from the studs on the front of dash.
9. Disconnect the engine harness clip from the wheelhouse splash shield.
10. Disconnect the following electrical connectors: Pressure cycling switch (1) Surge tank switch (2) Mass airflow (MAF) sensor (3)
11. Reposition the engine harness branch to top of engine.
12. Remove the connector position assurance (CPA) retainer at the ignition coil harness.
13. Disconnect the following electrical connectors: Manifold absolute pressure (MAP) sensor (1) Ignition coil harness (2) Engine coolant temperature (ECT) sensor (3)
14. Remove the engine harness bolt and studs
15. Remove the CPA retainer at the ignition coil harness.
16. Disconnect the following electrical connectors: Generator (2) Injector harness (3) Ignition coil harness (4) Electronic throttle control (ETC) (5) Purge valve solenoid (1)
17. Reposition the engine harness to the drivers side of the engine compartment.
18. Remove the bypass valve vacuum hose (1) from the intake manifold.
19. Disconnect the evaporative emission (EVAP) tube from the purge solenoid.
20. Unclip the EVAP tube from the fuel rail.
21. Disconnect the EVAP tube from the vent pipe at the rear of the engine.
22. Remove the EVAP tube.
23. If replacing the intake manifold, remove the fuel rail studs.
24. Remove the fuel rail.
25. Remove the intake manifold bolts.
26. Remove the intake manifold.
27. Remove and discard the intake manifold side gaskets.
28. Remove and discard the intake manifold end seals.
29. Remove the splash shield.
30. If replacing the intake manifold, refer to «Intake Manifold Disassemble»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__intake-manifold-disassemble) .
31. Clean and inspect the intake manifold. Refer to «Intake Manifold Cleaning and Inspection»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__intake-manifold-cleaning-and-inspection) .

1. If replacing the intake manifold, refer to «Intake Manifold Assemble»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__intake-manifold-assemble) .
2. Install the splash shield.
3. Ensure the splash shield (2) snap fits between the cylinder heads (1).
4. Apply a 5 mm (0.2 in) bead of sealer to the intake manifold. Refer to «Sealers, Adhesives, and Lubricants»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__sealers-adhesives-and-lubricants) for the correct part number.
5. Install the NEW intake manifold end seals.
6. Apply a 5 mm (0.2 in) bead of sealer (1) onto the end seals. Refer to «Sealers, Adhesives, and Lubricants»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__sealers-adhesives-and-lubricants) for the correct part number.
7. Install the NEW intake manifold side gaskets.
8. Ensure the intake manifold gasket tabs align with the hole in the head gasket.
9. Ensure the intake manifold gasket tabs align with the slot in the intake manifold end seals.
10. Install the intake manifold.
11. Install NEW intake manifold bolts.
12. Tighten the intake manifold bolts in the sequence shown, using 4 passes. Tighten: Tighten the bolts a first pass to 5 N.m (44 lb in). Tighten the bolts a second pass to 8 N.m (71 lb in). Tighten the bolts a third pass to 12 N.m (106 lb in). Tighten the bolts a final pass to 15 N.m (11 lb ft).
13. If replacing the intake manifold, install the fuel rail.
14. Install the fuel rail studs. Tighten: Tighten the studs to 12 N.m (106 lb in).
15. Install the EVAP tube.
16. Connect the EVAP tube to the vent pipe at the rear of the engine.
17. Clip the EVAP tube to the fuel rail.
18. Connect the EVAP tube to the purge solenoid.
19. Install the bypass valve vacuum hose (1) to the intake manifold.
20. Position the engine harness over the engine compartment.
21. Connect the following electrical connectors: Generator (2) Injector harness (3) Ignition coil harness (4) ETC (5) Purge valve solenoid (1)
22. Install the CPA retainer at the ignition coil harness.
23. Install the engine harness bolt and studs. Tighten: Tighten the bolt to 16 N.m (12 lb ft). Tighten the studs to 10 N.m (89 lb in).
24. Connect the following electrical connectors: MAP sensor (1) Ignition coil harness (2) ECT sensor (3)
25. Install the CPA retainer at the ignition coil harness.
26. Position engine harness branch over the top of engine.
27. Connect the following electrical connectors: Pressure cycling switch (1) Surge tank switch (2) MAF sensor (3)
28. Connect the engine harness clip to the wheelhouse splash shield.
29. Connect the engine harness clips to the studs on the front of dash.
30. Connect the fuel feed and return pipes.
31. Install the sight shield bracket and nuts (1). Tighten: Tighten the nuts to 5 N.m (44 lb in).
32. Install the sight shield to the bracket.
33. Snap the intake manifold sight shield to the stud.
34. Install the air cleaner outlet duct.
35. Tighten the clamps at the throttle body and air cleaner. Tighten: Tighten the clamps to 4 N.m (35 lb in).

1. Remove the engine sight shield. Refer to «Upper Intake Manifold Sight Shield Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .
2. Remove the connector position assurance (CPA) retainer from the ignition coil electrical connector.
3. Disconnect the ignition coil harness electrical connector (4).
4. Remove the spark plug wires from the spark plugs and ignition coils.
5. Remove the valve rocker arm cover bolts.
6. Remove the valve rocker arm cover. IMPORTANT: Valve rocker arm cover gaskets are reusable. Replace the gasket only if damaged.
7. Inspect the valve rocker arm cover gasket for cuts or damage.
8. Clean and inspect the valve rocker arm cover. Refer to «Valve Rocker Arm Cover Cleaning and Inspection»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__valve-rocker-arm-cover-cleaning-and) .

1. Install a new valve rocker arm cover gasket if the gasket was removed from the rocker arm cover.
2. Install the valve rocker arm cover.
3. Install the valve rocker arm cover bolts.
4. Tighten the valve rocker arm cover bolts in the sequence shown, using 2 passes as shown. Tighten: Tighten the bolts a first pass to 6 N.m (53 lb in). Tighten the bolts a final pass to 12 N.m (106 lb in).
5. Install the spark plug wires to the spark plugs and ignition coils.
6. Connect the ignition coil harness electrical connector (4).
7. Install the CPA retainer to the ignition coil electrical connector.
8. Install the engine sight shield. Refer to «Upper Intake Manifold Sight Shield Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .

1. Remove the engine sight shield. Refer to «Upper Intake Manifold Sight Shield Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .
2. Loosen the clamps at the throttle body and air cleaner.
3. Remove the air cleaner outlet duct.
4. Remove the connector position assurance (CPA) retainer from the ignition coil electrical connector (2).
5. Disconnect the ignition coil harness electrical connector (2).
6. Disconnect the engine coolant temperature (ECT) sensor electrical connector (3).
7. Remove the spark plug wires from the ignition coils.
8. Loosen the valve rocker arm cover bolts.
9. Remove the valve rocker arm cover. IMPORTANT: The valve rocker arm cover gasket may be reused if not removed from the valve rocker arm cover.
10. Replace the valve rocker arm cover gasket if it is cut or damaged.
11. Clean and inspect the valve rocker arm cover. Refer to «Valve Rocker Arm Cover Cleaning and Inspection»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__valve-rocker-arm-cover-cleaning-and) .

1. Install a NEW valve rocker arm cover gasket, if necessary.
2. Install the valve rocker arm cover.
3. Tighten the valve rocker arm cover bolts in sequence using 2 passes as shown. Tighten: Tighten the bolts a first pass to 6 N.m (53 lb in). Tighten the bolts a final pass to 12 N.m (106 lb in).
4. Install the spark plug wires to the ignition coils.
5. Connect the ECT sensor electrical connector (3).
6. Connect the ignition coil harness electrical connector (2).
7. Install the CPA retainer to the ignition coil electrical connector (2).
8. Install the air cleaner outlet duct.
9. Tighten the clamps at the throttle body and air cleaner. Tighten: Tighten the clamps to 4 N.m (35 lb in).
10. Install the engine sight shield. Refer to «Upper Intake Manifold Sight Shield Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .

1. Remove the valve rocker arm cover. Refer to «Valve Rocker Arm Cover Replacement - Left Side»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) and/or «Valve Rocker Arm Cover Replacement - Right Side»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .
2. Remove the valve rocker arm nuts, the valve rocker arm balls, and valve rocker arms.
3. Remove the valve pushrods.
4. Remove the valve rocker arm studs and pushrod guides.
5. Clean and inspect the valve rocker arms and pushrods. Refer to «Valve Rocker Arm and Push Rods Cleaning and Inspection»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__valve-rocker-arm-and-push-rods) .

1. Apply sealant to the valve rocker arm stud-to-cylinder head threads. Refer to «Sealers, Adhesives, and Lubricants»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__sealers-adhesives-and-lubricants) for the correct part number.
2. Install the pushrod guides and valve rocker arm studs. Tighten: Tighten the studs to 50 N.m (37 lb ft).
3. Install the valve pushrods.
4. Coat the valve rocker arm and valve rocker arm ball bearing surfaces with lubricant. Refer to «Sealers, Adhesives, and Lubricants»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__sealers-adhesives-and-lubricants) for the correct part number.
5. Install the valve rocker arms, the valve rocker arm balls, and the valve rocker arm nuts. Tighten: Tighten the nuts slowly to 35 N.m (26 lb ft) while guiding the tips of the rocker arms over the tips of the valves.
6. Install the valve rocker arm cover. Refer to «Valve Rocker Arm Cover Replacement - Left Side»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) or «Valve Rocker Arm Cover Replacement - Right Side»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .

Valve Stem Oil Seal and Valve Spring Replacement

Tools Required

1. J 5892-D Valve Spring Compressor
2. J 22794 Spark Plug Port Adapter
3. J 43105 Valve Stem Seal Installer. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .

1. Remove the valve rocker arms and pushrods. Refer to «Valve Rocker Arm and Push Rod Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .
2. Rotate the crankshaft until both valves are closed before installing the compressed air into the cylinder.
3. Remove the spark plug from the cylinder being serviced. Refer to «Spark Plug Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/testing-diagnostics/#engine-controls-and-fuel-81l-introduction-2-of-2) .
4. Remove the valve stem keys as followed: Install the J 22794 into the spark plug hole. Apply compressed air into the cylinder in order to hold the valves closed. Lightly tap the valve spring cap to loosen the valve stem keys. Install the J 5892-D to the cylinder head. Install the valve rocker arm nut. IMPORTANT: Tighten the valve rocker arm nut enough to hold J 5892-D in place. Using J 5892-D compress the valve spring.
5. Remove the valve stem keys (1).
6. Slowly release the J 5892-D .
7. Remove the J 5892-D from the cylinder head.
8. Remove the valve spring cap (2) and valve spring (3).
9. Remove the valve stem oil seal (4).

1. Lubricate the valve stem and outside diameter of the valve guide seal with clean engine oil.
2. Lubricate the rotators with clean engine oil. IMPORTANT: When installing valve seals, J 43105 must be used to achieve correct installation. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) . Failure to use J 43105 may cause excessive oil consumption. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .
3. Install the valve stem oil seal (2) over the valve tip and onto the valve guide using J 43105 . See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) . Tap the valve stem seal onto the valve guide until the J 43105 fully seats the seal. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .
4. Install the valve spring cap and the spring.
5. Install the valve spring (3).
6. Install the valve spring cap (2).
7. Using J 5892-D compress the valve spring.
8. Install the valve stem keys as follows: Apply a small amount of clean grease to hold the valve stem keys in place. Carefully release the J 5892-D . Make sure the valve stem keys do not move. Remove the J 5892-D from the valve assembly. Remove the compressed air from the cylinder being worked on.
9. Install the spark plug. Refer to «Spark Plug Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/testing-diagnostics/#engine-controls-and-fuel-81l-introduction-2-of-2) .
10. Install the valve rocker arms and pushrods. Refer to «Valve Rocker Arm and Push Rod Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .

Tools Required

J 3049-A Valve Lifter Remover

1. Remove the intake manifold. Refer to «Intake Manifold Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .
2. Remove the valve rocker arms and pushrods. Refer to «Valve Rocker Arm and Push Rod Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .
3. Remove the valve lifter guide retainer bolts and retainer.
4. Remove the valve lifter guides.
5. Remove the valve lifters.
6. Some valve lifter may be stuck in their bore due to gum or varnish deposits, These lifters can be removed using J 3049-A .
7. Clean and inspect the valve lifters. Refer to «Valve Lifters and Guides Cleaning and Inspection»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__valve-lifters-and-guides-cleaning-and) .

1. Coat the valve lifter rollers with lubricant. Refer to «Sealers, Adhesives, and Lubricants»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__sealers-adhesives-and-lubricants) for the correct part number.
2. Install the valve lifters.
3. Install the valve lifter guides over the flats on the valve lifters, making sure the rollers of the valve lifters are properly aligned with the camshaft lobes.
4. Install the valve lifter guide retainer.
5. Install the valve lifter guide retainer bolts. Tighten: Tighten the valve lifter guide retainer bolts to 25 N.m (18 lb ft).
6. Install the valve rocker arms and pushrods. Refer to «Valve Rocker Arm and Push Rod Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) . Install the intake manifold. Refer to «Intake Manifold Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .

1. Remove the oil level indicator from the indicator tube.
2. Disconnect the engine coolant temperature (ECT) sensor electrical connector.
3. Remove the ECT sensor connector from the indicator tube.
4. Remove the indicator tube bolt.
5. Remove the indicator tube bracket.
6. Remove the O-ring seal from the indicator tube.

1. Install a NEW O-ring seal onto the indicator tube.
2. Install the indicator tube into the oil pan.
3. Align the indicator tube bracket with the bolt hole in the block. NOTE: Refer to «Fastener Notice»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/oem-general-information/#warnings-and-cautions__fastener-notice) .
4. Install the indicator tube bolt. Tighten: Tighten the bolt to 25 N.m (18 lb ft).
5. Install the ECT sensor connector to the indicator tube.
6. Connect the ECT sensor electrical connector.
7. Install the oil level indicator to the indicator tube.

J 45059 Angle Meter

1. Remove the intake manifold. Refer to «Intake Manifold Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .
2. Remove the water crossover. Refer to «Engine Coolant Crossover Pipe Replacement (8.1L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
3. Remove the valve rocker arms and pushrods. Refer to «Valve Rocker Arm and Push Rod Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .
4. Remove the engine harness ground bolts.
5. Reposition the engine harness grounds (1 and 5) and ground strap (4) from the cylinder head.
6. Remove the exhaust manifold. Refer to «Exhaust Manifold Replacement - Left Side (8.1L Engine)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/exhaust/#engine-exhaust-system) .
7. Remove and discard the cylinder head bolts (1, 2, 3).
8. Remove the cylinder head.
9. Remove and discard the cylinder head gasket.
10. Clean and inspect the cylinder head. Refer to «Cylinder Head Cleaning and Inspection»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__cylinder-head-cleaning-and-inspection) .

1. Place a NEW cylinder head gasket into position.
2. Install the cylinder head.
3. If not pre-applied to the NEW cylinder head bolts, apply sealant. Refer to «Sealers, Adhesives, and Lubricants»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__sealers-adhesives-and-lubricants) for the correct part number.
4. Install the cylinder head bolts (1, 2, 3).
5. Tighten the cylinder head bolts. Tighten: Tighten the bolts a first pass in sequence to 30 N.m (22 lb ft) Tighten the bolts a second pass in sequence to 30 N.m (22 lb ft) then an additional 120 degrees using J 45059 . Tighten the bolts (1, 2, 3, 6, 7, 8, 9, 10, 11, 14, 16, 17) an additional 60 degrees, bolts (15, and 18) an additional 45 degrees, and bolts (4, 5, 12, and 13) an additional 30 degrees a final pass in sequence using J 45059 .
6. Install the exhaust manifold. Refer to «Exhaust Manifold Replacement - Left Side (8.1L Engine)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/exhaust/#engine-exhaust-system) .
7. Install the water crossover. Refer to «Engine Coolant Crossover Pipe Replacement (8.1L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
8. Position the engine harness grounds (1, 5) and ground strap (4) to the cylinder head.
9. Install the engine harness ground bolts. Tighten: Tighten the bolts to 16 N.m (12 lb ft).
10. Install the valve rocker arms and pushrods. Refer to «Valve Rocker Arm and Push Rod Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .
11. Install the intake manifold. Refer to «Intake Manifold Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .

J 45059 Angle Meter

1. Drain the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .
2. Remove the intake manifold. Refer to «Intake Manifold Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .
3. Remove the valve rocker arms and pushrods. Refer to «Valve Rocker Arm and Push Rod Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .
4. Remove the engine coolant temperature (ECT) sensor clip from the bracket.
5. Remove the ECT sensor from the cylinder head.
6. Remove the indicator tube bolt.
7. Remove the indicator tube bracket.
8. Remove the O-ring seal from the indicator tube.
9. Remove the heater inlet and outlet hoses from the hose bracket.
10. Remove the heater hose bracket bolts and bracket from the cylinder head.
11. Remove the water crossover. Refer to «Engine Coolant Crossover Pipe Replacement (8.1L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
12. Remove the exhaust manifold. Refer to «Exhaust Manifold Replacement - Right Side (8.1L Engine)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/exhaust/#engine-exhaust-system) .
13. Remove and discard the cylinder head bolts (1, 2, 3).
14. Remove the cylinder head.
15. Remove and discard the cylinder head gasket.
16. Clean and inspect the cylinder head. Refer to «Cylinder Head Cleaning and Inspection»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__cylinder-head-cleaning-and-inspection) .

1. Place a NEW cylinder head gasket into position.
2. Install the cylinder head.
3. If not pre-applied to the new cylinder heads bolts, apply sealant. Refer to «Sealers, Adhesives, and Lubricants»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__sealers-adhesives-and-lubricants) for the correct part number.
4. Install the cylinder head bolts (1, 2, 3).
5. Tighten the cylinder head bolts. Tighten: Tighten the cylinder head bolts a first pass in sequence to 30 N.m (22 lb ft). Tighten the cylinder head bolts a second pass in sequence to 30 N.m (22 lb ft) then an additional 120 degrees using J 45059 . Tighten the bolts (1, 2, 3, 6, 7, 8, 9, 10, 11, 14, 16, and 17) an additional 60 degrees, bolts (15, and 18) an additional 45 degrees, and bolts (4, 5, 12, and 13) an additional 30 degrees a final pass using J 45059 .
6. Install the exhaust manifold. Refer to «Exhaust Manifold Replacement - Right Side (8.1L Engine)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/exhaust/#engine-exhaust-system) .
7. Install the water crossover. Refer to «Engine Coolant Crossover Pipe Replacement (8.1L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
8. Install the heater hose bracket and bolts to the cylinder head. Tighten: Tighten the heater hose bracket bolts to 50 N.m (37 lb ft).
9. Install the heater inlet and outlet hoses to the hose bracket.
10. Install a NEW O-ring seal onto the indicator tube.
11. Install the indicator tube into the oil pan.
12. Align the indicator tube bracket with the bolt hole in the block.
13. Install the indicator tube bolt. Tighten: Tighten the bolt to 25 N.m (18 lb ft).
14. Apply sealant to the threads of the ECT sensor. Refer to «Sealers, Adhesives, and Lubricants»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__sealers-adhesives-and-lubricants) for the correct part number.
15. Install the ECT sensor to the cylinder head. Tighten: Tighten the ECT sensor to 50 N.m (37 lb ft).
16. Install the ECT sensor clip to the bracket.
17. Install the valve rocker arms and pushrods. Refer to «Valve Rocker Arm and Push Rod Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .
18. Install the intake manifold. Refer to «Intake Manifold Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .
19. Drain the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-static) or «Draining and Filling Cooling System (w/RPO HP2)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-wrpo) or «Draining and Filling Cooling System (Vac-N-Fill)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system__draining-and-filling-cooling-system-vac-n-fill) .

Crankshaft Balancer Replacement

Tools Required

1. J 38416-B Harmonic Balancer Remover. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .
2. J 42845 Crankshaft Balancer Installer. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .
3. J 42846 Crankshaft Balancer Protector Button. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .
4. J 42847 Flywheel Holding Tool. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .

1. Remove the air conditioning (A/C) belt. Refer to «Drive Belt Replacement - Air Conditioning»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .
2. Remove the fan. Refer to «Fan Replacement (Diesel)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Fan Replacement (Mechanical)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
3. Remove the starter motor. Refer to «Starter Motor Replacement (8.1L Engine)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
4. Install the J 42847 to the starter bolt holes. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) . Tighten: Tighten the J 42847 bolts to 50 N.m (37 lb ft).
5. Remove the crankshaft balancer bolt and washer.
6. Install the J 42846 onto the end of the crankshaft. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .
7. Install the J 38416-B (2) onto the J 42846 (1) in order to remove the crankshaft balancer. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) . Place the legs of the J 38416-B into the recesses cast into the backside of the balancer inner hub. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .
8. Tighten the center screw of the J 38416-B until the crankshaft balancer is clear of the crankshaft nose. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .
9. Remove the crankshaft balancer.
10. Remove the J 42846 from the end of the crankshaft. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .

1. Install the balancer onto the end of the crankshaft.
2. Install J 42845 to the crankshaft balancer. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) . IMPORTANT: Apply the lubricant that comes with J 42845 each time the tool is used. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) . Failure to lubricate the J 42845 may prevent the balancer from installing completely. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .
3. Using J 42845 install the balancer. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .
4. Tighten the J 42845 until the crankshaft balancer is completely seated against the crankshaft sprocket. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .
5. Remove the J 42845 from the crankshaft. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .
6. Install the crankshaft bolt and washer to the crankshaft. Tighten: Tighten the crankshaft balancer bolt to 255 N.m (189 lb ft).
7. Remove the J 42847 . See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .
8. Install the starter motor. Refer to «Starter Motor Replacement (8.1L Engine)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
9. Install the fan. Refer to «Fan Replacement (Diesel)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Fan Replacement (Mechanical)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
10. Install the A/C belt. Refer to «Drive Belt Replacement - Air Conditioning»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .

J 42851 Front Cover Oil Seal Installer. See Special Tools .

1. Remove the crankshaft balancer. Refer to «Crankshaft Balancer Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__crankshaft-balancer-replacement) .
2. Remove the crankshaft front cover oil seal.

1. Coat the crankshaft front cover oil seal with clean engine oil.
2. Using J 42851 install the oil seal. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .
3. Remove the J 42851 . See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .
4. Install the crankshaft balancer. Refer to «Crankshaft Balancer Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__crankshaft-balancer-replacement) .

J 42851 Front Cover Oil Seal Installer. See Special Tools .

1. Remove the water pump. Refer to «Water Pump Replacement (8.1L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
2. Remove the crankshaft balancer. Refer to «Crankshaft Balancer Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__crankshaft-balancer-replacement) .
3. Disconnect the camshaft position (CMP) sensor electrical connector (1).
4. Remove the engine harness clips from the battery cable channel.
5. Remove the CMP sensor bolt.
6. Remove the CMP sensor.
7. Remove the battery cable channel bolt.
8. Remove and reposition the battery cable channel.
9. Remove the engine front cover bolts (2).
10. Remove the engine front cover (1). IMPORTANT: The engine front cover gasket is reusable.
11. Remove the engine front cover gasket.
12. Remove the crankshaft front oil seal from the front cover.

1. Install a NEW crankshaft front oil seal using J 42851 . See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .
2. Lubricate the sealing surface of the crankshaft front oil seal with clean engine oil. IMPORTANT: The engine front cover must be installed and the fasteners tightened while the sealant is still wet to the touch.
3. Apply sealant in 2 places (1) on the engine block where the front cover meets the oil pan. Refer to «Sealers, Adhesives, and Lubricants»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__sealers-adhesives-and-lubricants) for the correct part number.
4. Install the engine front cover gasket into the front cover.
5. Install the front cover and gasket. Hold the front cover (1) up to the crankshaft (2). Lift the front cover (1) while sliding the cover over the crankshaft (2). Slide the front cover towards the engine block (5) while keeping the cover raised. Lower the cover down over the dowel pin (4), allowing the front cover to rest on the sealant (3).
6. Install the engine front cover bolts.
7. Tighten the engine front cover bolts. Tighten: Tighten the engine front cover bolts in sequence a first pass to 6 N.m (53 lb in). Tighten the engine front cover bolts in sequence a final pass to 12 N.m (106 lb in).
8. Position the battery cable channel into place.
9. Install the battery cable channel bolt. Tighten: Tighten the battery cable channel bolt to 9 N.m (80 lb in).
10. Inspect the CMP sensor O-ring for cuts, cracks, tears or damage. Replace as needed.
11. Apply a light film of clean engine oil to the CMP sensor O-ring.
12. Install the CMP sensor. Install the CMP sensor bolt. Tighten: Tighten the CMP sensor bolt to 12 N.m (106 lb in).
13. Install the engine harness clips to the battery cable channel.
14. Connect the CMP sensor electrical connector (1).
15. Install the crankshaft balancer. Refer to «Crankshaft Balancer Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__crankshaft-balancer-replacement) .
16. Install the water pump. Refer to «Water Pump Replacement (8.1L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .

Timing Chain and Sprockets Replacement

Tools Required

1. J 22102 Crankshaft Sprocket Installer. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .
2. J 42846 Crankshaft Protector Button. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .

1. Remove the engine front cover. Refer to «Engine Front Cover Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .
2. Aligned the timing marks on the camshaft and crankshaft sprockets.
3. Remove the camshaft sprocket bolts.
4. Remove the camshaft sprocket and timing chain.
5. Install the J 42846 (1) into the end of the crankshaft. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .
6. Remove the crankshaft sprocket using a suitable three jaw puller.
7. Clean and inspect the timing chain and sprockets. Refer to «Timing Chain and Sprockets Cleaning and Inspection»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__timing-chain-and-sprockets-cleaning-and) .

1. Use the J 22102 in order to install the crankshaft sprocket. Align the keyway of the crankshaft sprocket with the crankshaft pin.
2. Remove the J 22102 .
3. Rotate the crankshaft until the crankshaft sprocket alignment mark is in the 12 o'clock position.
4. Install the camshaft sprocket and timing chain.
5. Ensure that the crankshaft sprocket is aligned at the 12 o'clock position and the camshaft sprocket is aligned at the 6 o'clock position.
6. Install the camshaft sprocket bolts. Tighten: Tighten the bolts a to 30 N.m (22 lb ft).
7. Install the engine front cover. Refer to «Engine Front Cover Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .

1. Remove the intake manifold. Refer to «Intake Manifold Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .
2. Remove the oil pump drive bolt.
3. Remove the oil pump drive.
4. Clean and inspect the oil pump drive. Refer to «Oil Pump Drive Cleaning and Inspection»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__oil-pump-drive-cleaning-and-inspection) .

1. Apply grease to the oil pump drive gear for ease of assembly.
2. Line up the oil pump drive, making sure that the oil pump is fully seated in the engine block.
3. Install the oil pump, making sure that the oil pump drive is fully seated in the engine block. Tighten: Tighten the bolt to 25 N.m (18 lb ft).
4. Install the intake manifold. Refer to «Intake Manifold Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .

1. Remove the grille. Refer to «Grille Replacement (Chevrolet)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/exteriorinterior-trim/#exterior-trim) or «Grille Replacement (GMC)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/exteriorinterior-trim/#exterior-trim) .
2. Remove the air conditioning (A/C) condenser. Refer to «Condenser Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
3. Remove the valve lifters. Refer to «Valve Lifter Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .
4. Remove the timing chain and sprocket. Refer to «Timing Chain and Sprockets Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__timing-chain-and-sprockets-replacement) .
5. Remove the camshaft retainer bolts.
6. Remove the camshaft retainer.
7. Install three 8 - 1.25 x 100 mm bolts into the camshaft front bolt holes.
8. Using the bolts as a handle, carefully rotate and pull the camshaft out of the engine block.
9. Remove the bolts from the front of the camshaft.
10. Clean and inspect the camshaft. Refer to «Camshaft and Bearings Cleaning and Inspection»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__camshaft-and-bearings-cleaning-and-inspection) .

1. Apply lubricant to the following components: The camshaft lobes The camshaft bearing journals The camshaft bearings Refer to «Sealers, Adhesives, and Lubricants»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__sealers-adhesives-and-lubricants) for the correct part number.
2. Install three 8 - 1.25 x 100 mm bolts into the camshaft threaded bolt holes.
3. Using the bolts as a handle, carefully install the camshaft.
4. Remove the bolts from the front of the camshaft.
5. Install the camshaft retainer and bolts. Tighten: Tighten the bolts to 12 N.m (106 lb in).
6. Install the timing chain and sprocket. Refer to «Timing Chain and Sprockets Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__timing-chain-and-sprockets-replacement) .
7. Install the valve lifters. Refer to «Valve Lifter Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .
8. Install the A/C condenser. Refer to «Condenser Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
9. Install the grille. Refer to «Grille Replacement (Chevrolet)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/exteriorinterior-trim/#exterior-trim) or «Grille Replacement (GMC)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/exteriorinterior-trim/#exterior-trim) .

1. Remove the engine oil filter. Refer to «Engine Oil and Oil Filter Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .
2. Loosen the oil filter fitting using a hex wrench.
3. Remove the oil filter fitting.
4. Remove the oil filter bypass valves. Unstake the tangs on the oil bypass valves and remove with long nose pliers.
5. Discard the oil bypass valves.

1. Install NEW oil bypass valves. Stake the tangs on the new oil bypass valves.
2. Inspect the oil filter fitting, replace as necessary.
3. Install the oil filter fitting. Tighten: Tighten the oil filter fitting to 66 N.m (49 lb ft).
4. Install the oil filter. Refer to «Engine Oil and Oil Filter Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .

1. Remove the front differential, if equipped with 4-wheel drive (4WD). Refer to «Differential Carrier Assembly Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/differentials-drive-axles/#front-drive-axle) .
2. Remove the starter motor. Refer to «Starter Motor Replacement (8.1L Engine)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
3. Remove the oil pan skid plate bolts.
4. Remove the oil pan skid plate.
5. If equipped with 2-wheel drive (2WD), remove the crossbar bolts.
6. Remove the crossbar.
7. If equipped with 4WD, remove the crossbar bolts.
8. Remove the crossbar.
9. Drain the engine oil. Refer to «Engine Oil and Oil Filter Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .
10. Remove the oil level indicator. Refer to «Oil Level Indicator and Tube Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .
11. Disconnect the oil level sensor electrical connector (4).
12. Remove the engine harness clip from the oil pan.
13. Remove the oil level sensor from the oil pan.
14. Remove the battery cable channel bolt.
15. Remove and reposition the battery cable channel.
16. Remove the oil pan bolts.
17. Remove the oil pan and gasket.

1. Apply sealant to the sides of the front (2) and rear (1) crankshaft bearing caps, on both the left and right sides (4 locations total). Refer to «Sealers, Adhesives, and Lubricants»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__sealers-adhesives-and-lubricants) for the correct part number.
2. Install a NEW oil pan gasket into the oil pan groove, if required.
3. Install the oil pan.
4. Install the oil pan bolts.
5. Tighten the oil pan bolts. Tighten: Tighten the bolts a first pass in sequence to 10 N.m (89 lb in). Tighten the bolts a final pass in sequence to 25 N.m (18 lb ft).
6. Position the battery cable channel into place.
7. Install the battery cable channel bolt. Tighten: Tighten the bolt to 9 N.m (80 lb in).
8. Install the oil level sensor to the oil pan. Tighten: Tighten the sensor to 20 N.m (15 lb ft).
9. Install the engine harness clip to the oil pan.
10. Connect the oil level sensor electrical connector (4).
11. Install the oil level indicator. Refer to «Oil Level Indicator and Tube Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .
12. Fill the engine with oil. Refer to «Engine Oil and Oil Filter Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .
13. If equipped with 4WD, install the crossbar.
14. Install the crossbar bolts. Tighten: Tighten the bolts to 100 N.m (74 lb ft).
15. If equipped with 2WD, install the crossbar.
16. Install the crossbar bolts. Tighten: Tighten the bolts to 100 N.m (74 lb ft).
17. Install the oil pan skid plate.
18. Install the oil pan skid plate bolts. Tighten: Tighten the bolts to 20 N.m (15 lb ft).
19. Install the starter motor. Refer to «Starter Motor Replacement (8.1L Engine)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
20. Install the front differential, if equipped with 4WD. Refer to «Differential Carrier Assembly Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/differentials-drive-axles/#front-drive-axle) .

J 41712 Oil Pressure Sensor Socket

1. Remove the engine sight shield. Refer to «Upper Intake Manifold Sight Shield Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .
2. Disconnect the oil pressure sensor electrical connector (2).
3. Using J 41712 or equivalent, remove the oil pressure sensor.

1. Apply sealant to the threads of the oil pressure sensor. Refer to «Sealers, Adhesives, and Lubricants»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__sealers-adhesives-and-lubricants) for the correct part number.
2. Using J 41712 or equivalent, install the oil pressure sensor. Tighten: Tighten the sensor to 30 N.m (22 lb ft).
3. Connect the oil pressure sensor electrical connector (2).
4. Install the engine sight shield. Refer to «Upper Intake Manifold Sight Shield Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .

1. Drain the engine oil. Refer to «Engine Oil and Oil Filter Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .
2. Disconnect the oil level sensor electrical connector (4).
3. Remove the oil level sensor from the oil pan.

1. Install the oil level sensor to the oil pan. Tighten: Tighten the sensor to 20 N.m (15 lb ft).
2. Connect the oil level sensor electrical connector (4).
3. Fill the engine oil. Refer to «Engine Oil and Oil Filter Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .

1. Remove the oil pan. Refer to «Oil Pan Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .
2. Remove the oil pump bolt.
3. Remove and separate the oil pump, retainer, and driveshaft.
4. Discard the driveshaft retainer.
5. Remove the crankshaft oil deflector nuts.
6. Remove the crankshaft oil deflector.
7. Clean and inspect the oil pump. Refer to «Oil Pump Cleaning and Inspection»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__oil-pump-cleaning-and-inspection) .

1. Install the crankshaft oil deflector.
2. Install the crankshaft oil deflector nuts. Tighten: Tighten the nuts to 50 N.m (37 lb ft).
3. Assemble the oil pump, driveshaft and a NEW retainer.
4. Install the oil pump assembly. Position the oil pump onto the locating pins.
5. Install the oil pump bolt. Tighten: Tighten the bolts to 75 N.m (56 lb ft).
6. Install the oil pan. Refer to «Oil Pan Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .

Crankshaft Rear Oil Seal Replacement

Tools Required

1. J 43320 Crankshaft Rear Seal Puller. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .
2. J 42849 Crankshaft Rear Seal Installer. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .

1. Remove the flywheel. Refer to «Engine Flywheel Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .
2. Install the guide pins from J 43320 into the crankshaft. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .
3. Install the J 43320 over the guide pins. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .
4. Using a suitable drill, insert eight of the self-drilling sheet metal screws into the rear crankshaft seal, using a criss-cross pattern. The self-tapping screws are included with the J 43320 . See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .
5. Thread the center bolt of J 43320 into the crankshaft to remove the seal. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .
6. Remove the guide pins from the crankshaft.

1. Make sure the crankshaft is free of grit, loose rust, and burrs. Correct as needed.
2. Apply a very light film of oil onto the crankshaft sealing surface. DO NOT apply oil to the sealing surface of the engine block.
3. Install the seal onto J 42849 . See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .
4. Position the J 42849 against the crankshaft. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) . Thread the attaching screws into the tapped holes in the crankshaft.
5. Tighten the screws securely with a screwdriver in order to ensure that the seal is installed squarely over the crankshaft.
6. Rotate the center nut until the J 42849 bottoms. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .
7. Remove the J 42849 . See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .
8. Install the flywheel. Refer to «Engine Flywheel Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .

1. If equipped with a automatic transmission, remove the transmission. Refer to «Transmission Replacement (8.1L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/automatic-trans/#automatic-transmission-allison-introduction-2-of-2__transmission-replacement-with-81l-l18) for the Allison transmission.
2. Remove the engine flywheel bolts.
3. Remove the engine flywheel.
4. If equipped with a manual transmission, remove the clutch assembly. Refer to «Clutch Assembly Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/clutches-manual-hydraulic/#manual-transmission-clutch-system__clutch-assembly-replacement) .
5. Remove the engine flywheel bolts.
6. Remove the engine flywheel.
7. Clean and inspect the engine flywheel. Refer to «Engine Flywheel Cleaning and Inspection (Automatic Transmission)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__engine-flywheel-cleaning-and-inspection-automatic) or «Engine Flywheel Cleaning and Inspection (Manual Transmission)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__engine-flywheel-cleaning-and-inspection-manual) .

1. If equipped with a manual transmission, Install the engine flywheel.
2. If equipped with a automatic transmission, install the engine flywheel.
3. Install the engine flywheel bolts. Tighten: Tighten the bolts a first pass to 40 N.m (30 lb ft). Tighten the bolts a second pass to 80 N.m (59 lb ft). Tighten the bolts a final pass to 100 N.m (74 lb ft).
4. If equipped with a manual transmission, install the clutch assembly. Refer to «Clutch Assembly Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/clutches-manual-hydraulic/#manual-transmission-clutch-system__clutch-assembly-replacement) .
5. If equipped with a automatic transmission, install the transmission. Refer to «Transmission Replacement (8.1L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/automatic-trans/#automatic-transmission-allison-introduction-2-of-2__transmission-replacement-with-81l-l18) for the Allison transmission.

J 36857 Engine Lift Brackets

1. Open the hood.
2. Place fender covers over both fenders.
3. Raise the hood to the service position, perform the following: Remove the hood hinge bolts (1). Raise the hood until vertical. Install the hood hinge bolts until snug in the service position (2).
4. Loosen the clamps at the throttle body and air cleaner.
5. Remove the air cleaner outlet duct.
6. Disconnect the battery negative cable. Refer to «Battery Negative Cable Disconnection and Connection (Auxiliary Battery)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) or «Battery Negative Cable Disconnection and Connection (Single Battery)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
7. Disconnect the positive battery cable.
8. Remove the ignition coils. Refer to «Ignition Coil Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/testing-diagnostics/#engine-controls-and-fuel-81l-introduction-2-of-2) .
9. Relieve the fuel system pressure. Refer to «Fuel Pressure Relief (With CH 48027)»(ref-277873-S40865068532008012100000) or «Fuel Pressure Relief (Without CH 48027)»(ref-277873-S04692472202008012100000) .
10. Disconnect the fuel feed pipe (1) from the fuel rail. Refer to «Metal Collar Quick Connect Fitting Service»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/testing-diagnostics/#engine-controls-and-fuel-48l-53l-and-60l-introduction-2-of-2__metal-collar-quick-connect-fitting-service) .
11. Remove the air conditioning (A/C) compressor. Refer to «Compressor Replacement (8.1L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
12. Remove the radiator. Refer to «Radiator Replacement (8.1L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
13. Disconnect the throttle actuator control (TAC) module electrical connector (1).
14. Remove the vacuum lines from the engine, as required.
15. Remove the ground cable bolt at the engine block.
16. Remove the generator. Refer to «Generator Replacement (8.1L Engine)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
17. Remove the engine electrical harness and tie out of the way.
18. Raise and suitably support the vehicle safety stands. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/hoistjack/#general-information) .
19. Remove the starter motor. Refer to «Starter Motor Replacement (8.1L Engine)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
20. Remove the hoses from the power steering pump. Refer to «Power Steering Cooler Pipe/Hose Replacement (Rack and Pinion)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/manual-power-steering/#power-steering-system) or «Power Steering Cooler Pipe/Hose Replacement (With Hydroboost)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/manual-power-steering/#power-steering-system) or «Power Steering Cooler Pipe/Hose Replacement (Without Hydroboost)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/manual-power-steering/#power-steering-system) .
21. Remove the exhaust manifold pipe. Refer to «Exhaust Manifold Pipe Replacement (6.0L & 8.1L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/exhaust/#engine-exhaust-system) .
22. Remove the catalytic converter. Refer to «Catalytic Converter Replacement (6.0L & 8.1L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/exhaust/#engine-exhaust-system) .
23. Remove the torque converter bolts, if equipped.
24. Remove the clutch pressure plate bolts, if equipped.
25. Remove the bolts from the transmission to the engine. For the automatic transmission, refer to «Transmission Replacement (8.1L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/automatic-trans/#automatic-transmission-allison-introduction-2-of-2__transmission-replacement-with-81l-l18) for the Allison transmission. For the manual transmission, refer to «Transmission Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/manual-trans/#manual-transmission-nv-4500) for the NV 4500 transmission.
26. Remove the engine oil cooler lines from the engine block. Refer to «Engine Oil Cooler Hose/Pipe Replacement (2WD)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Engine Oil Cooler Hose/Pipe Replacement (4WD)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
27. Attach J 36857 to the rear of the right cylinder head and to the front of the left cylinder head.
28. Install the attaching bolt and washer. Use GM P/N 9428217 with GM P/N 15650963. Tighten: Tighten the lift bracket bolts to 40 N.m (30 lb ft).
29. Remove the engine mount heat shield bolts and shields.
30. Remove the engine mount to engine mount bracket bolts.
31. Remove the engine using a suitable lifting devise.
32. Install the engine onto a suitable engine stand.
33. Remove the generator mounting bracket. Refer to «Generator Bracket Replacement (8.1L Engine)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
34. Remove the A/C compressor/power steering pump bracket from the cylinder head.
35. Remove the lift brackets from the cylinder head.

1. Attach J 36857 to the rear of the right cylinder head and to the front of the left cylinder head.
2. Install the attaching bolt and washer. Use GM P/N 9428217 with GM P/N 15650963. Tighten: Tighten the lift bracket bolts to 40 N.m (30 lb ft).
3. Install the air compressor/power steering mounting bracket to the engine block. Tighten: Tighten the power steering pump bracket bolts and nut to 50 N.m (37 lb ft).
4. Install the generator bracket. Refer to «Generator Bracket Replacement (8.1L Engine)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
5. Remove the engine using a suitable lifting devise.
6. Install the engine into the vehicle.
7. Install the engine mount to engine mount bracket bolts.
8. Install the engine mount heat shield and bolts.
9. Remove the engine lift hooks from the cylinder heads.
10. Raise the vehicle and support with safety stands.
11. Install the engine oil cooler lines to the engine block. Refer to «Engine Oil Cooler Hose/Pipe Replacement (2WD)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) or «Engine Oil Cooler Hose/Pipe Replacement (4WD)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
12. Install the bolts from the transmission to the engine. For the automatic transmission, refer to «Transmission Replacement (8.1L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/automatic-trans/#automatic-transmission-allison-introduction-2-of-2__transmission-replacement-with-81l-l18) for the Allison transmission. For the manual transmission, refer to «Transmission Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/manual-trans/#manual-transmission-nv-4500) for the NV 4500 transmission.
13. Install the clutch pressure plate bolts, if equipped.
14. Install the torque converter bolts, if equipped.
15. Install the catalytic converter. Refer to «Catalytic Converter Replacement (6.0L & 8.1L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/exhaust/#engine-exhaust-system) .
16. Install the exhaust manifold pipe. Refer to «Exhaust Manifold Pipe Replacement (6.0L & 8.1L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/exhaust/#engine-exhaust-system) .
17. Install the hoses to the power steering pump. Refer to «Power Steering Cooler Pipe/Hose Replacement (Rack and Pinion)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/manual-power-steering/#power-steering-system) or «Power Steering Cooler Pipe/Hose Replacement (With Hydroboost)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/manual-power-steering/#power-steering-system) or «Power Steering Cooler Pipe/Hose Replacement (Without Hydroboost)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/manual-power-steering/#power-steering-system) .
18. Install the starter motor. Refer to «Starter Motor Replacement (8.1L Engine)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
19. Lower the vehicle.
20. Route the engine electrical harness.
21. Install the generator. Refer to «Generator Replacement (8.1L Engine)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
22. Install the ground cable bolt at the engine block. Tighten: Tighten the engine wiring harness bolt to 16 N.m (12 lb ft).
23. Install the vacuum lines to the engine.
24. Connect the TAC module electrical connector (1).
25. Install the radiator. Refer to «Radiator Replacement (8.1L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/cooling-system-mechanical/#engine-cooling-system) .
26. Install the A/C compressor. Refer to «Compressor Replacement (8.1L)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/automatic-hvac-system/#heating-ventilation-and-air-conditioning) .
27. Connect the fuel feed pipe (1) to the fuel rail.
28. Install the ignition coils. Refer to «Ignition Coil Replacement»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/testing-diagnostics/#engine-controls-and-fuel-81l-introduction-2-of-2) .
29. Connect the positive battery cable.
30. Connect the battery negative cable. Refer to «Battery Negative Cable Disconnection and Connection (Auxiliary Battery)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) or «Battery Negative Cable Disconnection and Connection (Single Battery)»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/charging-system/#battery-charging-system-and-starting-system) .
31. Install the air cleaner outlet duct.
32. Tighten the clamps at the throttle body and air cleaner. Tighten: Tighten the clamps to 4 N.m (35 lb in).
33. Remove fender covers from both fenders.
34. Remove the hood hinge bolts from the service position (2).
35. Lower the hood to the normal position.
36. Install the hood hinge bolts. Tighten: Tighten the hood hinge bolts to 25 N.m (18 lb ft).
37. Before starting a new engine or one that has been repaired, complete the following procedure. Prelube the engine. Refer to «Engine Prelubing»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__engine-prelubing) . Remove the fuel pump fuse and disconnect the coil harness connectors, then crank the engine until oil pressure is present. Crank the engine several times. Listen for any unusual noises or evidence that any of the parts are binding. Install the fuel pump fuse and connect the coil harness connectors and start the engine and listen for unusual noises. Check the vehicle oil pressure gage or light and confirm that the engine has acceptable oil pressure. If necessary install an oil pressure gage and measure the oil pressure. Run the engine at about 1000 RPM until the engine has reached normal operating temperature. Inspect for oil and or coolant leaks while the engine is running. Stop the engine and perform a final inspection for the proper engine oil and coolant levels. The final step is to perform the crankshaft position (CKP) sensor variation learn procedure. Refer to «Crankshaft Position System Variation Learn»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/testing-diagnostics/#engine-controls-and-fuel-81l-introduction-2-of-2__crankshaft-position-system-variation-learn) .

1. Raise and suitably support the vehicle with safety stands. Refer to «Lifting and Jacking the Vehicle»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/hoistjack/#general-information) .
2. Remove the oil pan drain plug and allow the engine oil to drain completely.
3. Clean the oil pan drain plug surface.
4. Remove the oil filter (2) from the engine block and allow the engine oil to drain completely.
5. Clean the oil filter surface.

1. Install a new oil filter (2) to the engine block. Tighten the oil filter per the oil filter manufacturers instruction printed on the oil filter box.
2. Install the oil pan drain plug. Tighten: Tighten the oil pan drain plug to 28 N.m (21 lb ft).
3. Lower the vehicle.
4. Fill the engine with oil. Refer to «Fluid and Lubricant Recommendations»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/lubrication-system/#maintenance-and-lubrication__fluid-and-lubricant-recommendations) .

Draining Fluids and Oil Filter Removal

1. Remove the oil pan drain plug (401).
2. Drain the engine oil.
3. Remove the oil filter (435).
4. Remove the left side engine block coolant drain hole plug (131) and the right side engine block coolant drain hole plug.
5. Drain the engine coolant.

Crankshaft Balancer Removal

Tools Required

1. J 38416-B Harmonic Balancer Remover. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .
2. J 42846 Crankshaft Protector Button. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .
3. J 42847 Flywheel Holding Tool. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .

1. Install the J 42847 (1) to the starter bolt holes. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) . Tighten: Tighten the J 42847 bolts to 50 N.m (37 lb ft).
2. Remove the crankshaft balancer bolt and washer.
3. Install the J 42846 onto the end of the crankshaft. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .
4. Install the J 38416-B (2) in order to remove the crankshaft balancer. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) . Place the legs of the J 38416-B into the recesses cast into the backside of the balancer inner hub. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .
5. Tighten the center screw of the J 38416-B until the crankshaft balancer is removed from the end of the crankshaft. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .
6. Remove the J 38416-B . See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .
7. Remove the crankshaft balancer.
8. Remove the J 42846 from the end of the crankshaft. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .
9. Remove the J 42847 (1). See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .

Engine Flywheel Removal (Automatic Transmission)

1. Remove the bolts.
2. Remove the flexplate.

Engine Flywheel Removal (Manual Transmission)

1. Remove the engine flywheel bolts.
2. Remove the engine flywheel.

Crankshaft Rear Oil Seal Removal

1. Install the J 43320 guide pins into the crankshaft. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .
2. Install the J 43320 over the guide pins. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .
3. Using a suitable drill, insert eight of the self-drilling sheet metal screws (1-8) into the rear crankshaft seal, using a criss-cross pattern. The self-drilling screws are included with the J 43320 . See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .
4. Thread the center bolt of J 43320 into the crankshaft to remove the seal. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .
5. Remove the J 43320 guide pins from the crankshaft. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .

Clutch Pilot Bearing Removal

1. Using the J 43276 , remove the clutch pilot bearing. Install the J 43276-1 tool body into the clutch pilot bearing. Using a wrench, secure the J 43276-1 tool body. Insert the J 43276-2 forcing screw into the J 43276-1 tool body. Rotate the J 43276-2 forcing screw clockwise into the J 43276-1 tool body until the clutch pilot bearing is completely removed from the crankshaft. Rotate the J 43276-2 forcing screw counterclockwise in order to remove the J 43276-2 forcing screw from the J 43276-1 tool body. Remove the J 43276-1 tool body from the clutch pilot bearing.
2. Discard the clutch pilot bearing.

Oil Level Indicator and Tube Removal

1. Remove the oil level indicator from the oil level indicator tube.
2. Remove the oil level indicator tube bolt.
3. Remove the oil level indicator tube from the oil pan.
4. Remove the O-ring seal from the oil level indicator tube.

Exhaust Manifold Removal - Left Side

1. Remove the spark plug wires from the spark plugs and ignition coils.
2. Remove the exhaust manifold heat shield bolts and nuts.
3. Remove the exhaust manifold heat shield.
4. Remove the exhaust manifold nuts and center bolt.
5. Remove the exhaust manifold.
6. Remove the exhaust manifold gasket.
7. Remove the spark plugs, if required.
8. Remove the exhaust manifold studs, if required.

Exhaust Manifold Removal - Right Side

1. Remove the spark plug wires from the spark plugs and ignition coils.
2. Remove the exhaust manifold heat shield bolts and nuts.
3. Remove the exhaust manifold heat shield.
4. Remove the exhaust manifold nuts and center bolt.
5. Remove the exhaust manifold.
6. Remove the exhaust manifold gasket.
7. Remove the spark plugs, if required.
8. Remove the exhaust manifold studs, if required.

Water Crossover Removal

1. Remove the drive belt tensioner bolts.
2. Remove the drive belt tensioner.
3. Remove the thermostat bypass hose and clamps.
4. Remove the engine coolant crossover bolts.
5. Remove the engine coolant crossover.
6. Remove the crossover gaskets.
7. Remove the water outlet bolts/studs (310).
8. Remove the water outlet (311).
9. Remove the thermostat (312) from the coolant crossover (308).

Tool Required

J 41240 Fan Clutch Remover and Installer

1. Use the J 41240 to retain the water pump pulley.
2. Remove the water pump pulley bolts (302) and pulley (303).
3. Remove the water pump bolts.
4. Remove the water pump.
5. Remove the water pump gaskets.

Intake Manifold Removal

1. Remove the vacuum plug (513), if required.
2. Remove the throttle body nuts (503).
3. Remove the throttle body (502) and gasket (501).
4. Remove the studs (504), if required.
5. Remove the fuel injection fuel rail bolts/studs.
6. Remove the fuel injection fuel rail with injectors.
7. Remove the intake manifold bolts.
8. Remove the intake manifold.
9. Remove and discard the intake manifold side gaskets.
10. Remove and discard the intake manifold end seals.
11. Remove the splash shield.

Valve Rocker Arm Cover Removal - Left Side

1. Remove the valve rocker arm cover bolts.
2. Remove the valve rocker arm cover.
3. Replace the valve rocker arm cover gasket if it is cut or damaged.

Valve Rocker Arm Cover Removal - Right Side

1. Remove the valve rocker arm cover bolts.
2. Remove the valve rocker arm cover.
3. Replace the valve rocker arm cover gasket if it is cut or damaged.

Valve Rocker Arm and Push Rod Removal

1. Remove the valve rocker arm nuts, the valve rocker arm balls and the valve rocker arms.
2. Remove the valve push rods.
3. Remove the valve rocker arm studs and push rod guides.

Cylinder Head Removal - Left Side

1. Remove and discard the cylinder head bolts (227, 228, 229).
2. Remove the cylinder head.
3. Remove the cylinder head gasket.
4. Discard the cylinder head gasket.

Cylinder Head Removal - Right Side

1. Remove and discard the cylinder head bolts (227, 228, 229).
2. Remove the cylinder head.
3. Remove the cylinder head gasket.
4. Discard the cylinder head gasket.

Valve Lifter Removal

1. Remove the valve lifter guide retainer bolts and retainer.
2. Remove the valve lifter guides.
3. Remove the valve lifters.
4. Some valve lifters may be stuck in their bore due to gum or varnish deposits. These valve lifters can be removed using J 3049-A .

Oil Pump Drive Removal

1. Remove the oil pump drive bolt.
2. Remove the oil pump drive.

Oil Pan Removal

1. Remove the oil level sensor from the oil pan.
2. Remove the oil pan bolts.
3. Remove the oil pan (400) and the oil pan gasket (404).

Oil Pump, Screen and Crankshaft Oil Deflector Removal

1. Remove the bolt that attaches the oil pump to the crankshaft rear bearing cap.
2. Remove the oil pump, driveshaft and retainer from the crankshaft rear bearing cap.
3. Separate the oil pump (422), driveshaft (420) and retainer (424).
4. Discard the driveshaft retainer (424).
5. Remove the crankshaft oil deflector nuts.
6. Remove the crankshaft oil deflector.

Engine Front Cover Removal

1. Remove the camshaft position (CMP) sensor bolt.
2. Remove the CMP sensor.
3. Inspect the CMP sensor O-ring for cuts, cracks, tears, or damage.
4. Replace the O-ring, as required.
5. Remove the engine front cover bolts (521).
6. Remove the engine front cover (522).
7. Remove the engine front cover gasket (523).
8. Remove the crankshaft front oil seal (125) from the engine front cover.

Timing Chain and Sprockets Removal

1. Measure the camshaft timing chain free play. If the chain can be moved back and forth in excess of 16 mm (0.625 in), replace the chain and sprockets.
2. Remove the camshaft sprocket bolts.
3. Remove the camshaft sprocket and the timing chain.
4. Install the J 42846 (1) into the end of the crankshaft. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .
5. Remove the crankshaft sprocket using a three jaw puller (2).

Camshaft Removal

1. Remove the camshaft retainer bolts.
2. Remove the camshaft retainer.
3. Install three 8-1.25 x 100 mm bolts in the camshaft front bolt holes.
4. Using the bolts as a handle, carefully rotate and pull the camshaft out of the engine block.
5. Remove the bolts from the front of the camshaft.

Piston, Connecting Rod, and Bearing Removal

Tools Required

1. J 24270 Cylinder Bore Ridge Reamer
2. J 42846 Crankshaft Protector Button. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .

1. Install the J 42846 onto the front of the crankshaft in order to rotate the crankshaft. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .
2. Rotate the crankshaft until the piston is at the bottom of the stroke (BDC).
3. Remove the cylinder bore ridge as necessary. Place a cloth on top of the piston. Perform the cutting operation with a J 24270 . Refer to the manufacturer's instructions before using the J 24270 . Remove the J 24270 . Rotate the crankshaft until the piston is at top dead center (TDC). Remove the cloth and the cuttings. Repeat the procedure for each piston.
4. Remove the connecting rod nuts.
5. Remove the connecting rod cap and the connecting rod lower bearing.
6. Install rubber fuel line (1) onto the connecting rod bolts to prevent contact with the crankshaft journal.
7. Remove the piston, connecting rod, and connecting rod bearing.
8. Remove the rubber fuel line (1) from the connecting rod bolts.
9. Remove the remaining piston and the connecting rod assemblies.
10. Remove the J 42846 from the front of the crankshaft. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .

Crankshaft and Bearings Removal

1. Remove the CKP sensor bolt.
2. Apply penetrating oil to the CKP sensor-to-engine block mating surface. Allow the penetrating oil to soak for several minutes, to help loosen the O-ring from the engine block.
3. Twist the sensor to loosen the O-ring seal. When removing the sensor, pull the sensor straight out of the engine block at the same angle the sensor was installed.
4. Inspect both CKP sensor O-rings for cuts, cracks, tears, or damage. Replace the O-rings, as needed.
5. Remove the crankshaft bearing cap bolts and studs.
6. Remove the crankshaft bearing caps.
7. Remove the crankshaft bearings from the crankshaft bearing caps.
8. Remove the crankshaft.
9. Remove the crankshaft bearings from the engine block.

Oil Filter Adapter Removal

1. Using a hex wrench, loosen the oil filter fitting.
2. Remove the oil filter fitting.
3. Inspect the oil filter fitting.
4. Replace the oil filter fitting, if necessary.
5. Remove the oil bypass valves, if required. Unstake the tangs on the oil bypass valves and remove with long nose pliers.
6. Discard the oil bypass valves, if removed.

Engine Block Plug Removal

1. Remove the oil pressure sensor using J 41712 (1).
2. Remove the camshaft rear bearing hole plug: Obtain a suitable self-threading screw. Drill a hole into the plug. Install the self-threading screw. Pull on the screw until the plug is removed from the bore. IMPORTANT: Use care not to damage the camshaft bearings. An alternate method to remove the plug would be to insert a long shaft or bar through the front of the engine and drive the plug from the bore.
3. Remove the left side knock sensor heat shield bolts.
4. Remove the left side knock sensor heat shield.
5. Remove the left side knock sensor.
6. Remove the right side knock sensor heat shield (720) and bolts (721).
7. Remove the right side knock sensor (719).
8. Remove the engine block oil cooler hose fittings.
9. Remove the rear oil gallery plugs.
10. Remove the front oil gallery plugs.
11. Remove the left side oil gallery plug.
12. Remove the top oil gallery plugs.
13. Remove the engine block coolant drain hole plug.
14. Remove the engine block coolant heater, if equipped.

Camshaft Bearing Removal

1. Remove the camshaft rear bearing hole plug, if not previously removed. Insert a long bar through the front of the engine and drive the plug out of the bore.
2. Prior to bearing removal, inspect the camshaft bearings (1-5) for loose fit in the engine block.
3. Select the expanding driver (4-8) and washer (2 or 3) from the J 33049 .
4. Assemble the J 33049 .
5. Insert the J 33049 through the front of the engine block and into the bearing.
6. Tighten the expander assembly nut until snug.
7. Push the guide cone into the front camshaft bearing in position 1 to align the J 33049 .
8. Drive the inner bearings from positions 2, 3, and 4.
9. Assemble the J 33049 handle, expanding driver, and washer.
10. Insert the J 33049 into the outer camshaft bearings.
11. Drive the outer bearings from the bore.

Engine Block Cleaning and Inspection

1. Boil the cylinder block in caustic solution.
2. Flush the cylinder block with clean water or steam.
3. Clean the following areas: All gasket surfaces Refer to «Replacing Engine Gaskets»(ref-277938-S01985332132008012100000) . Cylinder bores Remove excessive cylinder ring ridge, as required. Main bearing caps Oil galleries Remove all sludge or restrictions. Scale deposits from the coolant passages All dirt or debris from threaded bolt holes
4. Dry the block with compressed air.
5. Lubricate the cylinder bores with clean engine oil in order to prevent rusting.
6. Inspect the engine block for the following conditions: Gasket surfaces for deep gouges or other damage Crankshaft bearing bores for wear The surfaces where the crankshaft bearings contact the crankshaft bearing bore must be smooth. All crankshaft bearing bores must be round and uniform in the inside diameter (ID) at all the bearing supports. If a crankshaft bearing cap is damaged and requires replacement, refer to «Crankshaft and Bearings Cleaning and Inspection»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__crankshaft-and-bearings-cleaning-and-inspection) . Camshaft bearing bores for wear or damage Valve lifter bores for scuffing or wear Engine block for cracks or other damage Cylinder walls for scoring or gouges Coolant jackets for cracks Crankshaft bearing webs for cracks Engine mount bosses for damage The oil passages for restrictions
7. Inspect the engine block cylinder head deck for flatness, using a straight edge and a feeler gage. The surface must be flat within 0.100 mm (0.004 in).
8. Using a bore gage, measure the cylinder bore for taper, out-of-round, and oversize. Slide the bore gage up and down throughout the length of the cylinder bore. Inspect the bore both parallel and perpendicular to the centerline of the crankshaft at the top, center, and bottom of the bore. A cylinder bore that measures 107.940-107.990 mm (4.249-4.251 in) may be serviced with a standard size piston/connecting rod assembly. A cylinder bore that exceeds the maximum diameter must be serviced with an oversized piston/connecting rod assembly.

Boring Procedure

1. Before you use any type of boring bar, clean the top of the cylinder block in order to remove any dirt or burrs.
2. Carefully follow the instructions furnished by the manufacturer regarding use of equipment.
3. When you rebore cylinders, ensure all crankshaft bearing caps are in place. Tighten the bearing caps to the proper torque in order to avoid distortion of the bores in the final assembly. The crankshaft must be removed prior to cylinder boring.
4. When you take the final cut with a boring bar, leave 0.03 mm (0.001 in) on the diameter for finish honing. This gives the required position to the cylinder clearance specifications. Carefully perform the honing and boring operation in order to maintain the specified clearances between pistons, rings, and cylinder bores.

Honing Procedure

1. When honing the cylinders, follow the manufacturers recommendations for equipment use, cleaning, and lubrication. Use only clean, sharp stones of the proper grade for the amount of material you remove. Dull, dirty stones cut unevenly and generate excessive heat. Do not hone to a final grade with a coarse or medium-grade stone. Leave sufficient metal so that all stone marks may be removed with fine grade stones. The rehoned surface finish should be 0.25-0.50 micrometer (10-20 micro-inch). Perform final honing with a fine-grade stone and hone the cylinder in a cross-hatch pattern at 20 to 30 degrees to obtain the proper clearance.
2. During the honing operation, thoroughly clean the cylinder bore. Repeatedly inspect the cylinder bore for fit with the selected oversized piston. All measurements of the cylinder bore should be made with the components at normal room temperature.
3. To eliminate taper in the cylinder when honing, make full strokes of the hone in the cylinder. Repeatedly inspect the measurement at the top, the middle, and the bottom of the bore. The finish marks should be clean but not sharp. The finish marks should be free from embedded particles and torn or folded metal.
4. When finished, the reconditioned cylinder bores should have less than or meet the specified out-of-round or taper requirements.
5. After final honing and before the piston is inspected for fit, clean the bores with hot water and detergent. Scrub the bores with a stiff bristle brush and rinse the bores thoroughly with hot water. Do not allow any abrasive material to remain in the cylinder bores. Abrasive material may cause premature wear of new piston rings and cylinder bores. Abrasive material will contaminate the engine oil and may cause premature wear of the bearings. After washing the cylinder bore, dry the bore with a clean shop towel.
6. Perform final measurements of the cylinder bore.
7. Permanently mark the piston for the specific cylinder to which it has been fitted.
8. Apply clean engine oil to each cylinder bore in order to prevent rusting.

Crankshaft and Bearings Cleaning and Inspection

Tools Required

1. J 7872 Magnetic Base Dial Indicator
2. J 43690 Rod Bearing Clearance Checking Tool
3. J 43690-100 Rod Bearing Clearance Checking Tool - Adapter Kit
4. J 45059 Angle Meter

Crankshaft Inspection

1. Clean the crankshaft in solvent. Remove all sludge or restrictions from the oil passages.
2. Dry the crankshaft and bearings with compressed air.
3. Inspect the crankshaft for the following conditions: Crankshaft journals (1) should be smooth with no evidence of scoring or damage Deep grooves (2) Scratches or uneven wear (3) Pitted surfaces (4) Wear or damage to the thrust journal surfaces Scoring or damage to the rear seal surface Restrictions to oil passages Damage to threaded bolt holes
4. Inspect the crankshaft pin for damage: Measure for proper installed height (a). Correct height should be 2.00-2.25 mm (0.078-0.088 in). Replace the crankshaft pin if it is damaged.
5. Inspect the reluctor wheels for cracked, bent, or broken teeth. Measure between the crankshaft shoulder and the front reluctor wheel (1). Measure the gap between the front and rear reluctor wheels (2). The maximum allowable gap is 0.15 mm (0.006 in).
6. Measure the crankshaft main journals and the crankpins for out-of-round and taper.
7. Using a suitable fixture, support the crankshaft.
8. Measure the crankshaft runout using the J 7872 . Crankshaft runout should not exceed 0.051 mm (0.002 in).
9. Inspect the crankshaft thrust wall surface (1) for wear and/or excessive runout (2). Refer to «Engine Mechanical Specifications»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__engine-mechanical-specifications) .

Crankshaft and Connecting Rod Bearing Inspection

1. Inspect the bearings for craters or pockets. Flattened sections on the bearing halves also indicate fatigue.
2. Inspect the bearings for excessive scoring or discoloration.
3. Inspect the bearings for dirt or debris embedded into the bearing material.
4. Inspect the bearings for improper seating indicated by bright, polished sections of the bearings.

Crankshaft and Connecting Rod Bearing Clearance Measurement

The crankshaft and connecting rod bearings are of the precision insert type and do not use shims for adjustment.

Crankshafts with journals that measure less than minimum specifications must be replaced.

Micrometer Method for Crankshaft Bearings

1. Measure the crankshaft main journal diameter with a micrometer in several places along the length, approximately 90 degrees apart, a minimum of 4 places. Average the measurements.
2. Determine the taper and the out-of-round. Refer to «Engine Mechanical Specifications»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__engine-mechanical-specifications) .
3. Install the NEW crankshaft bearings into the crankshaft bearing caps and the engine block.
4. Install the bearing cap bolts and studs. Tighten: Tighten the bearing cap bolts a first pass to 30 N.m (22 lb ft). Tighten the bearing cap studs a first pass to 30 N.m (22 lb ft). Tighten the bearing cap bolts a final pass an additional 90 degrees using the J 45059 . Tighten the bearing cap studs a final pass an additional 80 degrees using the J 45059 .
5. Measure the crankshaft bearing inside diameter (ID), using an inside micrometer. Measure at a minimum of 4 places. Average the measurements.
6. In order to determine the crankshaft bearing clearance, subtract the crankshaft journal diameter from the crankshaft bearing ID.
7. Compare the crankshaft bearing clearance to the specifications. Refer to «Engine Mechanical Specifications»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__engine-mechanical-specifications) .
8. If the crankshaft bearing clearances exceeds specifications, install undersize crankshaft bearings to achieve the correct clearance.
9. Measure the new crankshaft bearing ID, using an inside micrometer.
10. Replace the crankshaft if the proper clearances cannot be obtained with standard size bearings.

Micrometer Method for Connecting Rod Bearings

1. Measure the crankpin diameter with a micrometer in several places along the length, approximately 90 degrees apart, a minimum of 4 places. Average the measurements.
2. Determine the taper and the out-of-round. Refer to «Engine Mechanical Specifications»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__engine-mechanical-specifications) .
3. Install the NEW connecting rod bearings into the connecting rod cap and the connecting rod.
4. Install the connecting rod cap and the original nuts. Tighten: Tighten the connecting rod nuts a first pass to 30 N.m (22 lb ft). Tighten the connecting rod nuts a final pass an additional 90 degrees, using the J 45059 .
5. Measure the connecting rod bearing ID, using an inside micrometer.
6. Compare the connecting rod bearing clearance specifications. Refer to «Engine Mechanical Specifications»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__engine-mechanical-specifications) .
7. If the connecting rod bearing clearances exceed specifications, replace components, as required.

Plastic Gage Method for Crankshaft Bearings

1. Install the crankshaft and the new crankshaft bearings into the block. Do not damage the crankshaft reluctor rings.
2. Install the gaging plastic the full width of the crankshaft journal.
3. Install the bearing cap bolts and studs. Tighten: Tighten the bearing cap bolts a first pass to 30 N.m (22 lb ft). Tighten the bearing cap studs a first pass to 30 N.m (22 lb ft). Tighten the bearing cap bolts a final pass an additional 90 degrees, using the J 45059 . Tighten the bearing cap studs a final pass an additional 80 degrees, using the J 45059 .
4. Remove the crankshaft bearing cap bolts and the crankshaft bearing caps. The gaging plastic may adhere to either the crankshaft journal or the crankshaft bearing surfaces.
5. On the edge of the gaging plastic envelope there is a graduated scale. Without removing the gaging plastic, measure the compressed width at the widest point.
6. If the flattened gaging plastic tapers toward the middle or toward the end, there may be a difference in clearance indicating taper, low spot, or other irregularity of the crankshaft bearing or the crankshaft journal. Normally the crankshaft journals wear evenly and are not out-of-round. However, if a crankshaft bearing is being fitted to an out-of-round 0.0254 mm (0.001 in) maximum crankshaft journal, ensure to fit to the maximum diameter of the crankshaft journal. If the crankshaft bearing is fitted to the minimum diameter and the crankshaft journal is excessively out-of-round, the interference between the crankshaft bearing and the crankshaft journal will result in rapid crankshaft bearing failure.
7. Compare the crankshaft bearing clearance to the specifications. Refer to «Engine Mechanical Specifications»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__engine-mechanical-specifications) .
8. If the crankshaft bearing clearances exceeds specifications, replace components, as required.
9. Measure the new crankshaft bearing ID, using the same method.
10. Replace the crankshaft if the proper clearances cannot be obtained with standard size bearings.
11. Remove the flattened gaging plastic.
12. Measure the remaining crankshaft journals.

Plastic Gage Method for Connecting Rod Bearings

1. Install the connecting rod bearings (118) into the connecting rod (119) and the connecting rod cap (117).
2. Using rubber fuel line (1) over the connecting rod bolts, install the piston and connecting rod assembly onto the crankpin journal.
3. Install the gaging plastic the full width of the crankpin journal.
4. Install the connecting rod cap and the original nuts. Tighten: Tighten the connecting rod nuts a first pass to 30 N.m (22 lb ft). Tighten the connecting rod nuts a final pass an additional 90 degrees, using the J 45059 .
5. Remove the connecting rod nuts and cap. The gaging plastic may adhere to either the crankpin journal or the connecting rod bearing surface.
6. There is a graduated scale on the edge of the gaging plastic envelope. Without removing the gaging plastic, measure the compressed width at the widest point. If the flattened gaging plastic tapers toward the middle or toward the end, there may be a difference in clearance, indicating taper, low spot, or other irregularity of the crankshaft bearing or the crankpin journal.
7. Normally the crankpin journals wear evenly and are not out-of-round. However, if a connecting rod bearing is being fitted to an out-of-round 0.0254 mm (0.001 in) maximum crankpin journal, ensure to fit to the maximum diameter of the crankpin journal. If the connecting rod bearing is fitted to the minimum diameter and the crankpin journal is excessively out-of-round, the interference between the connecting rod bearing and the crankpin journal will result in rapid connecting rod bearing failure.
8. Compare the connecting rod bearing clearance to the specifications. Refer to «Engine Mechanical Specifications»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__engine-mechanical-specifications) .
9. If the connecting rod bearing clearances exceed specifications, replace components, as required.
10. Remove the flattened gaging plastic.
11. Measure the remaining crankpin journals.

Measuring Crankshaft End Play

1. Install the J 7872 , or equivalent, to the cylinder block, with the dial indicator plunger against one of the counterweights of the crankshaft.
2. Firmly thrust the end of the crankshaft first rearward then forward. This lines up the rear crankshaft bearing and the crankshaft thrust surfaces.
3. With the crankshaft pushed forward, zero the dial indicator. Move the crankshaft rearward and read the end play measurement on the dial indicator. An optional method is to insert a feeler gage between the crankshaft and the bearing surface and measure the clearance. Refer to «Engine Mechanical Specifications»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__engine-mechanical-specifications) .
4. If the correct end play cannot be obtained, inspect the crankshaft thrust wall surface or surfaces for wear and/or excessive runout.
5. Turn the crankshaft in order to inspect for binding. If the crankshaft does not turn freely, loosen the crankshaft bearing bolts and studs, 1 cap at a time, until the tight bearing is located. The following conditions could cause a lack of clearance at the bearing: Burrs on the crankshaft bearing cap Foreign matter between the crankshaft bearing and the block or the crankshaft bearing cap A faulty crankshaft bearing

Measuring Connecting Rod Side Clearance

1. Install the J 7872 , or equivalent, to the cylinder block, with the dial indicator plunger against the side of the pair of connecting rods.
2. With the connecting rods pushed forward, zero the dial indicator. Firmly move the pair of connecting rods side to side and read the measurement on the dial indicator. An optional method is to insert a feeler gage between the connecting rod caps and measure the connecting rod side clearance. Refer to «Engine Mechanical Specifications»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__engine-mechanical-specifications) .

Measuring Connecting Rod Bearing Clearance - Using J 43690/J 43690-100

The J 43690 and J 43690-100 have been developed as a more accurate method to measure connecting rod bearing clearances. The instructions below provide an overview of tool set-up and usage. For more detailed information, refer to the tool manufacturers instruction sheets.

Scheme 125

J 43690 Rod Bearing Clearance Checking Tool

1. J 43690-20 Swivel Base (1)
2. J 43690-19 Dial Indicator (2)
3. J 43690-2 Base (3)
4. J 43690-5, J 43690-6 Handle (4)
5. J 43690-10, J 43690-11 Foot (5)
6. 280307 Screw (6)
7. J 43690-1 Pivot Arm Assembly (7)
8. J 43690-3, J 43690-7, J 43690-8 Screws (8)
9. 280319 Screw (9)
10. 280311 Screw (10)
11. J 43690-17, J 43690-18 Adapter (11)
12. 280310 Pin (12)

Scheme 126

J 43690-100 Rod Bearing Clearance Checking Tool - Adapter Kit

1. J 43690-104 Spacer (1)
2. J 43690-105 Retainer Plate (2)
3. 505478 Bolt (3)
4. 511341 Bolt (4)
5. J 43690-106 Retainer Plate (5)
6. J 43690-107 Cap (6)
7. J 43690-102 Foot (7)
8. J 43690-101 Pivot Arm Assembly (8)
9. J 43690-103 Adapter (9)
10. 505439 Adapter (10)

1. Rotate the crankshaft until the journal/connecting rod to be measured is in the 12 o'clock position.
2. Remove a bearing cap bolts (1).
3. Remove the bearing half and bearing cap (2).
4. Insert a piece of paper card stock onto the crankshaft journal.
5. Install the bearing half and cap (2) and bolts (1). Refer to «Fastener Tightening Specifications»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__fastener-tightening-specifications) .
6. Install the following tools: J 43690-2 (5) J 43690-8 (4) J 43690-1 (2) 280310 (3) J 43690-5 (1)
7. Install the swivel base (1) and dial indicator (2).
8. Adjust, per the manufacturers instructions, and measure the connecting rod bearing clearance. A connecting rod with a clearance in excess of 0.081 mm (0.0032 in) is considered excessive. Service components, as required.

Crankshaft Balancer Cleaning and Inspection

1. Clean the crankshaft balancer in solvent.
2. Dry the crankshaft balancer with compressed air.
3. Inspect the crankshaft balancer for the following conditions: Damaged belt grooves (3) Debris in the belt grooves (3) Worn, grooved, or damaged hub seal surface (1) Minor imperfections on the hub seal surface may be removed with a polishing compound or fine grade of emery cloth. A crankshaft balancer hub seal surface with excessive scoring, grooves, rust, or other damage must be replaced. Worn, chunking, or deteriorated rubber between the hub and pulley (2)
4. Repair or replace the crankshaft balancer, as necessary.

Engine Flywheel Cleaning and Inspection (Automatic Transmission)

1. Clean the flex plate in solvent.
2. Dry the flex plate with compressed air.
3. Inspect the flex plate for the following conditions: Stress cracks around the engine flex plate-to-torque converter mounting bolt hole locations (1) and/or engine flex plate-to-crankshaft (2, 3) IMPORTANT: Do not attempt to repair the welded areas that retain the ring gear to the flex plate. Install a new flex plate. Cracks at welded areas that retain the ring gear onto the flex plate (4) Damaged or missing ring gear teeth (5)

Engine Flywheel Cleaning and Inspection (Manual Transmission)

1. Clean the engine flywheel in solvent.
2. Dry the engine flywheel with compressed air.
3. Inspect the manual transmission engine flywheel for the following conditions: Pitted surface (1) Scoring or grooves (2) Rust or other surface damage (3) Damaged ring gear teeth (4) Loose or improperly positioned ring gear The ring gear has an interference fit onto the engine flywheel and should be positioned completely against the flange of the engine flywheel.

Piston and Connecting Rod Disassemble

1. Remove the connecting rod bearings (118) from the rod (119) and cap (117).
2. Using piston ring pliers, remove the piston rings from the piston.
3. Rotate the piston pin retainers until the retainer end gap is positioned in the cutout area (1) of the pin bore.
4. Remove the retainers starting in the cutout area of the pin bore.
5. Remove the pin from the piston and connecting rod.
6. The piston and pin are a matched set and are not to be serviced separately. Mark, sort or organize the piston and matching piston pin.

Piston, Connecting Rod, and Bearings Cleaning and Inspection

1. Clean the piston and pin (144), connecting rod (119), and cap (117) in solvent.
2. Dry the components with compressed air.
3. Clean the piston ring grooves with a suitable ring groove cleaning tool.
4. Clean the piston oil lubrication holes and slots.
5. Inspect the piston for the following conditions: Eroded areas (1) on the top of the piston Scuffed or damaged skirt (2) Cracks in the piston ring lands, the piston skirt, or the pin bosses Piston ring grooves for nicks, burrs, or other warpage which may cause the piston ring to bind
6. Inspect the piston pin for scoring, wear, or other damage.
7. Measure the piston ring-to-piston ring groove side clearance. Refer to «Engine Mechanical Specifications»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__engine-mechanical-specifications) . Insert the edge of the piston ring into the piston ring groove. Roll the piston ring completely around the piston. If binding is caused by a distorted piston ring groove, MINOR imperfections may be removed with a fine file. If binding is caused by a distorted piston ring, replace the piston ring.
8. Measure the piston ring side clearance with a feeler gage.
9. If the side clearance is too small, try another piston ring set. Refer to «Engine Mechanical Specifications»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__engine-mechanical-specifications) .
10. If the proper piston ring-to-piston ring groove clearance cannot be achieved, replace the piston and pin assembly.
11. Inspect the connecting rod for an out-of-round bearing bore.
12. Inspect the connecting rod for twisting.
13. Inspect the connecting rod for damage to the connecting rod bolt threads.
14. Measure the piston compression ring end gap. Place the compression ring into the cylinder bore. Push the compression ring into the cylinder bore to approximately 6.5 mm (0.25 in) above the ring travel. The ring must be square to the cylinder wall. Use a feeler gage in order to measure the end gap. Select another size ring set if the end gap exceeds specifications.

Piston and Connecting Rod Assemble

1. Assemble the right bank pistons and connecting rods with the arrow (1) on the top of the piston facing front of engine and the master or larger flange (2) of the connecting rod facing rear of engine.
2. Assemble the left bank pistons and connecting rods with the arrow (1) on the top of the piston facing front of engine and the master or larger flange (2) of the connecting rod facing front of engine.
3. Install the retainer. The retainer should be seated in the groove of the pin bore.
4. Lubricate the pin and pin bore with clean engine oil.
5. Install the piston pin to the piston and connecting rod.
6. Install the retainer. The retainer should be seated in the groove of the pin bore. Ensure the pin moves freely within the piston pin bore.
7. Using piston ring pliers, install the piston rings onto the piston.
8. Install the lower oil control piston ring spacer onto the piston.
9. Install the lower oil control piston ring onto the piston (1).
10. Install the upper oil control piston ring onto the piston (1).
11. Position the oil control piston ring end gaps a minimum of 90 degrees apart (1, 2, 3).
12. Install the lower compression piston ring onto the piston. The mark (1) on the side of the piston ring should face the top of the piston.
13. Install the upper compression piston ring onto the piston. The mark (1) on the side of the piston ring should face the top of the piston.
14. Position the compression ring end gaps 120 degrees apart.
15. Install the connecting rod bearings (118) to the rod (119) and cap (117).

Camshaft and Bearings Cleaning and Inspection

1. Clean the camshaft in solvent.
2. Dry the camshaft with compressed air.
3. Inspect the camshaft retainer plate for damage.
4. Inspect the camshaft for the following conditions: Camshaft bearing journals (1) that are: Worn Scored Damaged Worn camshaft lobes (2) Damaged sprocket bolt threads (3) Damaged sprocket pin (206)
5. Measure the camshaft journals with a micrometer. Refer to «Engine Mechanical Specifications»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__engine-mechanical-specifications) .
6. Measure for excessive camshaft runout, using the J 7872 . Mount the camshaft in a suitable fixture. Use the J 7872 in order to measure for a bent camshaft. Refer to «Engine Mechanical Specifications»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__engine-mechanical-specifications) .
7. Replace the camshaft if runout exceeds specifications.
8. Inspect the camshaft bearings (1-5) for wear or damage.
9. Replace the camshaft bearings, if necessary. Refer to «Camshaft Bearing Removal»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__camshaft-bearing-removal) and «Camshaft Bearing Installation»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .

Scheme 127

1. Assemble the tool handle (10), expanding driver (4-8), and washer (2 or 3).
2. Insert the J 33049 tool into the engine block end camshaft bearings.
3. Drive the end bearings into the bore.
4. Select the expanding driver (4-8) and washer (2 or 3) from the J 33049 .
5. Assemble the tool.
6. Insert the J 33049 tool through the front of the engine block and to the inner bearing bores.
7. Install the bearing onto the expanding driver.
8. Tighten the expander assembly nut until the tool is snug in the bearing.
9. Align the oil lubrication hole in the bearing with the oil galleries in the engine block.
10. Push the guide cone into the front camshaft bearing bore to align the tool.
11. Drive the bearing into the bore.

Timing Chain and Sprockets Cleaning and Inspection

1. Clean the camshaft timing components in solvent.
2. Dry the components with compressed air.
3. Inspect the camshaft timing chain for binding or wear.
4. Inspect the camshaft and crankshaft sprockets for the following conditions: Worn teeth (1) Damaged teeth (2) Chipped teeth (3) Uneven wear on one edge of the teeth Worn valleys between the sprocket teeth Crankshaft sprocket keyway for wear

Valve Rocker Arm and Push Rods Cleaning and Inspection

1. Clean the components with cleaning solvent.
2. Dry the components with compressed air.
3. Inspect the valve rocker arms for wear or scoring in the ball area.
4. Inspect the valve rocker arm push rod sockets and valve stem tip mating surfaces.
5. Inspect the valve rocker arm ball for wear or scoring. These surfaces should be smooth with no scoring or exceptional wear.
6. Inspect the push rods (1, 2) for worn or scored ends. These surfaces should be smooth with no scoring or exceptional wear.
7. Inspect the push rods for bends. Roll the push rods on a flat surface to determine if the push rod is bent. If the push rod rolls smoothly, it is acceptable. If the push rod does not roll smoothly, replace the push rod.
8. Inspect the push rod oil passages for restrictions. Clean out the push rod tube with compressed air. Inspect the push rod tube for obstructions. A clear push rod allows light through. Replace push rods that cannot be cleaned out.
9. Inspect the rocker arm studs for the following conditions: Damaged threads (1) Excessive wear or damage (2) made by contact between the rocker arm and rocker arm stud
10. Valve rocker arm studs with excessive wear and/or damage must be replaced.
11. Inspect the push rod guides for the following conditions: Wear between the push rod and the push rod guide (1) Bent push rod guide (2) Cracks
12. Push rod guides with excessive wear and/or damage must be replaced.

Valve Lifters and Guides Cleaning and Inspection

1. Dry the components with compressed air.
2. Inspect the valve lifters for the following conditions: A damaged, mis-positioned, or broken clip (1) A scored or worn pushrod socket (2) A severely scuffed or worn lifter body (3) If the valve lifter body shows scuffing or wear, inspect the engine block valve lifter bores for wear or damage. Flat spots on the roller (4) A loose pin (5) A plugged oil hole (6)
3. If flat spots are found on the lifters, inspect the corresponding lobe on the camshaft for damage.
4. Inspect the valve lifter guides for the following conditions: Excessive guide slot side wear Cracks Damage
5. Inspect the valve lifter guide retainer for the following conditions: Wear, damage, or stress cracking in the leg areas Wear or damage around the retainer bolt holes

Cylinder Head Disassemble

1. Use the J 8062 in order to compress the valve springs.
2. Remove the valve stem keys (220).
3. Release and remove the J 8062 .
4. Remove the cap (219).
5. Remove the valve spring (218).
6. Remove the valve stem oil seal (217) from the valve guide.
7. Remove the valve rotator (216).
8. Remove the valve (232).
9. Disconnect the engine coolant temperature (ECT) sensor from the bracket.
10. Remove the ECT sensor from the cylinder head.
11. Remove the ECT sensor bracket and bolt.
12. Remove the cylinder head coolant hole plug from the cylinder head.

Cylinder Head Cleaning and Inspection

Tools Required

1. J 8089 Carbon Removal Brush
2. J 9666 Valve Spring Tester
3. J 8001 Dial Indicator Set

Cleaning Procedure

1. Clean the valve stems and heads on a buffing wheel.
2. Clean the following components in solvent: Valve stem keys (220) Valve spring cap (219) Valve spring (218) Valve Rotators (216) Valve (232) Cylinder head
3. Dry the components with compressed air.
4. Use the J 8089 in order to clean the carbon from the combustion chambers.

Visual Inspection Procedure

Inspect the cylinder head for the following conditions

1. Damaged gasket surfaces
2. Damage to threaded bolt holes
3. Burnt or eroded areas in the combustion chamber
4. Cracks in the exhaust ports and combustion chambers
5. External cracks in the water chamber
6. Restrictions in the intake or exhaust passages
7. Restrictions in the cooling system passages

Flatness Measurement Procedure

1. Measure the cylinder head for warpage with a straight edge and feeler gage. A cylinder head block deck with warpage in excess of 0.050 mm (0.002 in) within a 150.0 mm (6.0 in) area must be repaired or replaced. A cylinder head exhaust manifold deck with an overall warpage in excess of 0.102 mm (0.004 in) must be repaired or replaced. A cylinder head intake manifold deck with warpage in excess of 0.080 mm (0.003 in) must be repaired or replaced.
2. A cylinder head block deck can be resurfaced up to 0.305 mm (0.012 in) maximum removal.
3. A cylinder head that requires excessive resurfacing must be replaced.

Valve Inspection Procedure

1. Inspect the valves for the following conditions: Burnt or damaged areas (1) Undersized valve margin (2) Bent stem (3) Scoring or other damage to the stem (4) Worn key groove (5) Worn stem tip (6)
2. Inspect the valve contact surface for the following conditions: Undersized margin (1) Pitted surface (2) Burnt or eroded areas (3) Acceptable edge, margin (4)
3. Valves with excessive damage must be replaced.

Valve Spring Inspection and Measurement

1. Inspect the valve springs for broken coils or coil ends.
2. Use the J 9666 in order to measure the valve spring force. Refer to «Engine Mechanical Specifications»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__engine-mechanical-specifications) .
3. If the valve spring tension is low, use a shim to increase tension.
4. Inspect the valve spring tension again. A valve spring that does not meet specification must be replaced.

Valve Guide Measurement Procedure

1. Measure the valve stem-to-guide clearance. Clamp the J 8001 on the exhaust port side of the cylinder head. IMPORTANT: The indicator stem must contact the side of the valve stem just above the valve guide. Locate the indicator so that the movement of the valve stem from side to side, crosswise to the cylinder head, causes a direct movement of the indicator stem. Drop the valve head approximately 1.6 mm (0.064 in) off the valve seat. Use light pressure when moving the valve stem from side to side in order to obtain a clearance reading. Refer to «Engine Mechanical Specifications»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__engine-mechanical-specifications) .
2. Valve guide (2) with excessive clearance must be repaired. Refer to «Valve Guide Reaming/Valve and Seat Grinding»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .
3. Replace the cylinder head if the valve guide cannot be repaired or reamed to accept an oversize valve stem.

Valve Guide Reaming Procedure for Oversized Valve Stems

1. Ream the valve guide, as necessary, in order to achieve proper valve stem-to-guide clearance with the new, oversized valve stems.
2. Always recondition the valve seat after reaming the valve guide bores or installing new valves.
3. Replace the cylinder head if the valve guide cannot be repaired or reamed to accept an oversize valve stem.

Valve Reconditioning Procedure

1. Replace the valve if the valve stem shows excessive wear or is warped.
2. Reface pitted valves on a valve refacing machine in order to ensure the correct relationship between the head and the stem.
3. Replace the valve if the edge of the head is less than 0.79 mm (0.031 in) thick after grinding.

Valve Seat Reconditioning Procedure

1. Recondition the valve seats.
2. The valves must seat perfectly for the engine to deliver optimum power and performance.
3. Correct contact (1) between each valve and valve seat in the cylinder head is essential in order to ensure the heat in the valve head is properly carried away.
4. The valve seats should be concentric to within 0.050 mm (0.002 in) total indicator runout.

Cylinder Head Assemble

Tools Required

1. J 8062 Valve Spring Compressor
2. J 43105 Valve Stem Seal Installer. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .

Inspecting Valve Spring Installed Height

1. Install the valve rotator (3), the valve (4), the valve spring cap (1), and the valve stem keys (5) into the cylinder head.
2. Using a snap gage or inside micrometer, measure the distance from the top of the valve rotator to the bottom of the valve spring cap. Refer to «Engine Mechanical Specifications»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__engine-mechanical-specifications) for proper valve spring installed height specifications.
3. Install a valve spring seat shim if the valve spring installed height measurement is greater than the specification.
4. Measure the valve spring installed height again. Replace the cylinder head if the valve spring installed height cannot be obtained.

Valve Installation

1. Lubricate the valve stems (232) with clean engine oil.
2. Insert the valves into their proper locations.
3. Install the necessary valve spring shims onto the cylinder head, if applicable.
4. Lubricate the rotators (216) with clean engine oil.
5. Install the rotators over the guide and on top of the cylinder head or valve spring shims, if applicable.
6. Lubricate the valve stem seal and the outside diameter (OD) of the valve guide with clean engine oil.
7. Install the valve stem oil seals (217) over the valve tip and onto the valve guides, using the J 43105 (1). See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) . Tap the valve stem seal onto the valve guide until the J 43105 fully seats the seal. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .
8. Install the valve springs (218).
9. Install the valve spring caps (219).
10. Use the J 8062 in order to compress the valve spring. Compress the spring enough to clearly see the valve stem key grooves of the valve.
11. Install the valve stem keys. Use grease to hold the keys in place. Ensure that the keys seat properly in the upper groove of the valve stem.
12. Release and remove the J 8062 .
13. Lightly tap the end of the valve stem with a plastic-face hammer in order to seat the keys.
14. Apply sealant GM P/N 12346004 (Canadian P/N 10953480), or equivalent, to the threads of the engine coolant temperature (ECT) sensor.
15. Install the ECT sensor into the right cylinder head. Tighten: Tighten the ECT sensor to 50 N.m (37 lb ft).
16. Install the ECT sensor bracket and bolt. Tighten: Tighten the ECT sensor bracket bolt to 50 N.m (37 lb ft).
17. Apply sealant GM P/N 12346004 (Canadian P/N 10953480), or equivalent, to the threads of the cylinder head coolant hole plug.
18. Install the cylinder head coolant hole plug into the left cylinder head. Tighten: Tighten the cylinder head coolant hole plug to 50 N.m (37 lb ft).

Oil Pump Disassemble

1. Remove the oil pump driveshaft and retainer.
2. Remove the oil pump cover bolts.
3. Remove the pump cover.
4. Remove the drive gear and the driven gear. Matchmark the gear teeth for assembly.
5. Remove the following items: The retaining pin The pressure relief valve spring The pressure relief valve

Oil Pump Cleaning and Inspection

1. Clean the oil pump components in cleaning solvent.
2. Dry the components with compressed air.
3. Inspect the gears (427, 428) for the following conditions: Scoring Chipping Galling Excessive wear
4. Inspect the oil pump housing (422) for the following conditions: Damaged bolt hole threads Worn oil pump driveshaft bore Scoring or excessive wear within the housing Worn driven gear shaft
5. Inspect for a collapsed pressure relief valve spring.
6. Inspect the pressure relief valve for scoring or wear. The valve should move freely within the bore of the housing.

Oil Pump Assemble

1. Install the following items: The pressure relief valve The pressure relief valve spring The retaining pin
2. Apply clean engine oil to the drive gear, the driven gear, and the housing gear surfaces.
3. Install the drive gear and the driven gear into the pump body. Align the matching marks on the gears. Install the smooth side of the gear toward the pump cover.
4. Install the oil pump cover.
5. Install the oil pump cover bolts. Tighten: Tighten the oil pump cover bolts to 12 N.m (106 lb in).
6. Inspect the oil pump for smooth operation by turning the oil pump driveshaft by hand.
7. Install the oil pump driveshaft and the new retainer.

Oil Pump Drive Cleaning and Inspection

1. Clean the oil pump drive in cleaning solvent.
2. Dry the oil pump drive with compressed air.
3. Inspect the oil pump drive (1) for the following conditions: Excessive play in the oil pump drive bearing Damage to the oil pump drive clamp bolt hole (2) Damaged gear (3) for the following conditions: Chipping Galling Wear Damage to the oil pump driveshaft tang
4. Damage to the oil pump drive body (4).
5. If the oil pump drive is to be used again, lubricate the bearing with clean engine oil and apply grease to all gear teeth (3).

Valve Rocker Arm Cover Cleaning and Inspection

1. Remove the white wiring harness clip locks.
2. Disconnect the ignition coil wiring harness from the ignition coils.
3. Remove the ignition coil wiring harness retainer bolts.
4. Open the 2 wiring harness retainers and remove the ignition coil wiring harness.
5. Remove the ignition coil bolts.
6. Remove the ignition coils.
7. Clean the valve rocker arm cover in solvent.
8. Dry the covers with compressed air.
9. Inspect the covers for the following conditions: Gouges or damage to the sealing surfaces Cracking or damage to the valve cover gasket Debris or damage to the bolt hole threads
10. Install the ignition coils.
11. Install the ignition coil bolts. Tighten: Tighten the ignition coil bolts to 12 N.m (106 lb in).
12. Install and secure the ignition coil wiring harness into the 2 wiring harness retainers.
13. Install the ignition coil wiring harness retainer bolts. Tighten: Tighten the ignition coil wiring harness retainer bolts to 12 N.m (106 lb in).
14. Connect the ignition coil wiring harness to the ignition coils. Ensure the connectors for cylinders 1 and 3, and cylinders 6 and 8 are connected to the corresponding ignition coils.
15. Install the white wiring harness clip locks.

Oil Pan Cleaning and Inspection

1. Remove the oil pan gasket (404) from the groove in the oil pan (400).
2. Clean the oil pan in solvent.
3. Dry the oil pan with compressed air.
4. Inspect the oil pan for the following conditions: The drain plug hole for damaged threads Gouges or damage to the oil pan sealing surfaces Cracks or damage to the exterior of the oil pan Damage to the oil level indicator tube area Damage to the oil pan gasket

Intake Manifold Disassemble

1. Remove the vacuum plug (513).
2. Remove the throttle body nuts (503).
3. Remove the throttle body (502) and gasket (501).
4. Discard the gasket.
5. Remove the throttle body studs (504), if required.
6. Remove the oil fill cap (418).
7. Remove the oil fill tube (416) and bolt (419).
8. Remove the bolt and manifold absolute pressure (MAP) sensor.
9. Inspect the MAP sensor grommet for damage.
10. Remove the evaporative emission (EVAP) tube.
11. Remove the EVAP canister purge solenoid valve and bolt.
12. Inspect the O-ring seal for damage. Replace as needed.

Intake Manifold Cleaning and Inspection

1. Clean the intake manifold in an approved solvent. Clean debris out of all bolt holes. Clean the intake manifold gasket sealing surfaces. Clean all intake manifold ports.
2. Dry the intake manifold with compressed air.
3. Inspect the following components: The intake manifold bolt holes (1) for cracks and/or damage The manifold absolute pressure (MAP) sensor sealing surface (2) for damage The evaporative emission (EVAP) purge valve sealing surface (4) for damage The purge valve bolt has a sealer that may come off during removal of the bolt. Ensure all sealant is removed from the bolt hole. The intake manifold-to-cylinder head sealing surfaces (3) for damage The throttle body studs (5) for damage Replace, as necessary. The throttle body mounting surface (6) for damage The oil fill tube hole (7) for signs of leakage Seal, as necessary. Positive crankcase ventilation (PCV) port (8) for debris or varnish buildup

Intake Manifold Assemble

1. Apply a very light film of clean engine oil to the evaporative emission (EVAP) canister purge solenoid valve O-ring seal.
2. Install the EVAP purge valve.
3. Apply thread sealer GM P/N 12345493 (Canadian P/N 10953488), or equivalent, to the threads of the EVAP purge valve bolt.
4. Install the EVAP purge valve bolt. Tighten: Tighten the bolt to 8 N.m (71 lb in).
5. Install the EVAP tube.
6. Install the MAP sensor.
7. Install the MAP sensor bolt. Tighten: Tighten the MAP sensor bolt to 12 N.m (106 lb in).
8. Lubricate the oil fill tube O-ring seal (415) with clean engine oil.
9. Install the oil fill tube (416).
10. Install the oil fill tube bolt (419). Tighten: Tighten the oil fill tube bolt to 12 N.m (106 lb in).
11. Install the oil fill cap (418).
12. Install the throttle body gasket (501).
13. Install the throttle body (502).
14. Install the throttle body nuts (503). Tighten: Tighten the throttle body nuts to 10 N.m (89 lb in).
15. Install the vacuum plug (513).

Exhaust Manifold Cleaning and Inspection

1. Clean the exhaust manifolds in solvent.
2. Dry the exhaust manifolds with compressed air.
3. Inspect the exhaust manifolds for the following conditions: Damage to the gasket sealing surfaces Damage to the exhaust manifold studs Broken or damaged heat shields Cracks in the exhaust manifold Restrictions within the exhaust passages
4. Measure the alignment, or surface flatness, of the exhaust manifold flanges, using a straight edge and a feeler gage. Exhaust manifold surface flatness must not exceed 0.254 mm (0.01 in).
5. If the surface flatness is not within specifications, the exhaust manifold is warped and must be replaced.

1. Clean the engine coolant crossover (308) and water outlet (311) in solvent.
2. Dry the components with compressed air.

Inspection Procedure

1. Inspect the engine coolant crossover (308) for the following conditions: Corrosion or damage to the gasket sealing surfaces Corrosion or damage to the thermostat bypass hose fitting Corrosion or damage to the heater hose fitting Corrosion or damage to the threads of the water outlet
2. Inspect the water outlet (311) for corrosion or damage.

Water Pump Cleaning and Inspection

1. Inspect the water pump pulley for damage at the belt contact area (1) and the pulley-to-water pump mounting surface.
2. Clean all excess dirt and debris from the water pump housing.
3. Inspect the water pump for the following conditions: Leakage at the hose fitting (1) Leakage at the water pump weep hole (3) A stain around the weep hole is acceptable. If leakage occurs, dripping with the engine running and the cooling system pressurized, replace the water pump. Gasket sealing surfaces (2) for excessive scratches or gouging Restrictions within the internal coolant passages (6) Excessive side-to-side play in the pulley shaft If the shaft end play exceeds 0.381 mm (0.015 in), replace the water pump. Rotate the pump shaft by hand and inspect for operation roughness. If the hub wobbles, is noisy, or feels rough when rotated, replace the water pump. The shaft and fan hub must turn straight and smoothly. Damage to threaded bolt holes (4) Damage to the fan clutch mounting threads (5)

Scheme 128

The thread repair process involves a solid, thin walled, self-locking, carbon steel, bushing type insert (1). During the bushing installation process, the driver tool expands the bottom external threads of the insert into the base material (2). This action mechanically locks the insert in place. Also, when installed to the proper depth, the flange of the insert will be seated against the counterbore of the repaired hole.

1. Drill out the threads of the damaged hole (1). M6 inserts require a minimum drill depth of 15 mm (0.59 in). M8 inserts require a minimum drill depth of 20 mm (0.79 in). M10 inserts require a minimum drill depth of 23.5 mm (0.93 in).
2. Using compressed air, clean out any chips.
3. Counterbore the hole to the full depth permitted by the tool (1).
4. Using compressed air, clean out any chips.
5. Using a tap wrench (2), tap the threads of the drilled hole. M6 inserts require a minimum tap depth of 15 mm (0.59 in). M8 inserts require a minimum tap depth of 20 mm (0.79 in). M10 inserts require a minimum tap depth of 23.5 mm (0.93 in).
6. Using compressed air, clean out any chips.
7. Spray cleaner GM P/N 12346139, GM P/N 12377981 (Canadian P/N 10953463), or equivalent, into the hole.
8. Using compressed air, clean any cutting oil and chips out of the hole.
9. Lubricate the threads of the installer tool (2) with the driver oil (1).
10. Install the insert (2) onto the driver tool (1).
11. Apply threadlock LOCTITE™ 277, J 42385-109 (1), or equivalent, to the insert OD threads (2).
12. Install the insert (2) into the hole. Install the insert until the flange of the insert contacts the counterbored surface. Continue to rotate the installer tool (1) through the insert. The installer tool will tighten up before screwing completely through the insert. This is acceptable. You are forming the bottom threads of the insert and mechanically locking the insert to the base material threads.
13. Inspect the insert for proper installation into the hole. A properly installed insert (1) will be either flush or slightly below flush with the surface of the base material (2).

Service Prior to Assembly

1. Dirt causes premature wear in the rebuilt engine. Clean all components.
2. Use the proper tools to measure the components when inspecting for excessive wear. Components not within the manufacturers specification must be repaired or replaced.
3. When the components are installed into an engine, return the components to their original location, position, and direction.
4. During assembly, lubricate all moving parts with clean engine oil, unless otherwise specified. This provides initial lubrication when the engine is first started.

Engine Block Plug Installation

1. Apply sealant GM P/N 12346004 (Canadian P/N 10953480), or equivalent, to the engine coolant drain hole plug threads.
2. Install the engine coolant drain hole plug into the block. Tighten: Tighten the engine coolant drain hole plug to 60 N.m (40 lb ft).
3. Apply sealant GM P/N 12346004 (Canadian P/N 10953480), or equivalent, to the engine block coolant heater threads, if applicable.
4. Install the engine block coolant heater into the block. Tighten: Tighten the engine block coolant heater to 50 N.m (37 lb ft).
5. Apply sealant GM P/N 12346004 (Canadian P/N 10953480), or equivalent, to the threads of the oil gallery plugs.
6. Install the engine block top oil gallery plugs. Tighten: Tighten the top oil gallery plugs to 20 N.m (15 lb ft).
7. Apply sealant GM P/N 12346004 (Canadian P/N 10953480), or equivalent, to the left side oil gallery plug threads.
8. Install the engine block left side oil gallery plug. Tighten: Tighten the left side oil gallery plug to 30 N.m (22 lb ft).
9. Apply sealant GM P/N 12346004 (Canadian P/N 10953480), or equivalent, to the front oil gallery plug threads.
10. Install the front oil gallery plugs. Tighten: Tighten the front oil gallery plugs to 30 N.m (22 lb ft).
11. Apply sealant GM P/N 12346004 (Canadian P/N 10953480), or equivalent, to the rear oil gallery plug threads.
12. Install the rear oil gallery plugs. Tighten: Tighten the rear oil gallery plugs to 20 N.m (15 lb ft).
13. Apply sealant GM P/N 12346004 (Canadian P/N 10953480), or equivalent, to the engine block oil cooler hose fitting threads.
14. Install the engine block oil cooler hose fittings. Tighten: Tighten the engine block oil cooler hose fittings to 23 N.m (17 lb ft).
15. Install the left knock sensor to the engine block. Tighten: Tighten the left knock sensor to 20 N.m (15 lb ft).
16. Install the left side knock sensor heat shield.
17. Install the left side knock sensor heat shield bolts. Tighten: Tighten the bolts to 12 N.m (106 lb in).
18. Install the right knock sensor (719) to the engine block. Tighten: Tighten the right side knock sensor to 20 N.m (15 lb ft).
19. Install the right side knock sensor heat shield (720) and bolts (721). Tighten: Tighten the bolts to 12 N.m (106 lb in).
20. Apply sealant GM P/N 12346004 (Canadian P/N 10953480), or equivalent, to the engine block coolant drain hole plug threads.
21. Install the engine block coolant drain hole plugs. Tighten: Tighten the coolant drain hole plugs to 30 N.m (22 lb ft).
22. Apply sealer GM P/N 12377901 (Canadian P/N 10953504) to the outside diameter (OD) of the new camshaft rear bearing hole plug.
23. Install the NEW camshaft rear bearing hole plug to the proper depth of 6.2-7.6 mm (0.244-0.299 in) (a).
24. Apply sealant GM P/N 12346004 (Canadian P/N 10953480), or equivalent, to the oil pressure sensor threads.
25. Install the oil pressure sensor. Tighten: Using the J 41712 (1), tighten the oil pressure sensor to 30 N.m (22 lb ft).

Oil Filter Adapter Installation

1. If removed, install the new oil filter bypass valves. Stake the tangs on the oil filter bypass valves.
2. Install the oil filter fitting. Tighten: Tighten the oil filter fitting to 66 N.m (49 lb ft).

Crankshaft and Bearings Installation

Tools Required

1. J 8001 Dial Indicator Set
2. J 45059 Angle Meter

1. Install the crankshaft upper bearings into the block. Apply clean engine oil to the bearing surfaces.
2. Install the crankshaft lower bearings into the crankshaft bearing caps. Apply clean engine oil to the bearing surfaces.
3. Install the crankshaft.
4. Apply a 13 mm (0.5 in) (a) light film of sealant GM P/N 1052942, (Canadian P/N 10953466), or equivalent, to the rear bearing cap sealing face or to the rear bearing cap channel of the engine block. Apply the sealant to the bearing cap mating surface and bearing cap channel from the rear seal bore to the oil pan surface.
5. Install the crankshaft bearing caps in the location the caps were marked and originally removed from.
6. Install the bearing cap bolts and studs. Tighten: Tighten the bearing cap 1-4 bolts a first pass to 30 N.m (22 lb ft). Tighten the bearing cap 1-4 studs a first pass to 30 N.m (22 lb ft). Tighten the bearing cap 1-4 bolts a final pass an additional 90 degrees, using the J 45059 . Tighten the bearing cap 1-4 studs a final pass an additional 80 degrees, using the J 45059 . Tighten the bearing cap 5 bolts and studs to 30 N.m (22 lb ft). Loosen the bearing cap 5 bolts and studs. Tighten the bearing cap 5 bolts and studs to 5 N.m (44 lb in).
7. Thrust the crankshaft firmly rearward.
8. Thrust the crankshaft firmly forward. Tighten: Tighten the bearing cap 5 bolts a first pass to 30 N.m (22 lb ft). Tighten the bearing cap 5 studs a first pass to 30 N.m (22 lb ft). Tighten the bearing cap 5 bolts a final pass an additional 90 degrees, using the J 45059 . Tighten the bearing cap 5 bolts a final pass an additional 80 degrees, using the J 45059 .
9. Measure the crankshaft end play as follows: Install the J 8001 , or equivalent, to the cylinder block, with the dial indicator plunger against one of the counterweights of the crankshaft. Firmly thrust the end of the crankshaft first rearward then forward. This lines up the rear crankshaft bearing and the crankshaft thrust surfaces. With the crankshaft pushed forward, zero the dial indicator. Move the crankshaft rearward, and read the end play measurement on the dial indicator. An optional method is to insert a feeler gage between the crankshaft and the bearing surface and measure the clearance. Refer to «Engine Mechanical Specifications»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__engine-mechanical-specifications) . If the correct end play cannot be obtained, inspect for the following conditions: Verify that the correct size crankshaft bearing has been installed. Refer to «Engine Mechanical Specifications»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__engine-mechanical-specifications) . Inspect the crankshaft thrust wall surface or surfaces for wear and/or excessive runout. Refer to «Engine Mechanical Specifications»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__engine-mechanical-specifications) . Turn the crankshaft in order to inspect for binding. If the crankshaft does not turn freely, loosen the crankshaft bearing bolts and studs, 1 cap at a time, until the tight bearing is located. The following conditions could cause a lack of clearance at the bearing: Burrs on the crankshaft bearing cap Foreign material between the bearing and the block Foreign material between the bearing and the bearing cap A faulty crankshaft bearing Improper bearing size
10. Inspect the CKP sensor O-ring for cuts, cracks, tears, or damage. Replace the O-ring, as needed. Lubricate the CKP sensor O-ring with clean engine oil.
11. Install the CKP sensor into the block. There may be a slight resistance as the O-ring seats into the engine block.
12. Apply thread adhesive GM P/N 12345493 (Canadian P/N 10953488), or equivalent, to the CKP sensor bolt.
13. Install the CKP sensor bolt. Tighten: Tighten the CKP sensor bolt to 12 N.m (106 lb in).

Piston, Connecting Rod, and Bearing Installation

Tools Required

1. J 8037 Piston Ring Compressor
2. J 8087 Cylinder Bore Gage
3. J 45059 Angle Meter

Piston Selection

1. Inspect the engine block cylinder bore. Refer to «Engine Block Cleaning and Inspection»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__engine-block-cleaning-and-inspection) .
2. Inspect the piston/connecting rod assembly for damage. Refer to «Piston, Connecting Rod, and Bearings Cleaning and Inspection»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__piston-connecting-rod-and-bearings-cleaning) .
3. Use the J 8087 in order to measure the cylinder bore diameter. Refer to «Engine Block Cleaning and Inspection»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__engine-block-cleaning-and-inspection) .
4. Measure the J 8087 with a micrometer. Record the reading.
5. Compare the cylinder bore measurement to the specifications. Refer to «Engine Mechanical Specifications»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__engine-mechanical-specifications) . If the cylinder bore is within specifications, select the original piston or a new, original size piston. If the cylinder bore is not within specifications, select the next oversized piston/connecting rod assembly, then bore and hone the cylinder bore to fit the oversize piston.

Piston Installation

1. Coat the following components with clean engine oil: The piston The piston rings The cylinder bore The bearing surfaces
2. Install rubber fuel lines (1) onto the connecting rod bolts.
3. Position the right bank piston and connecting rod assemblies for proper installation. The arrow (1) on the top of the piston should be facing the front of the engine and the master or larger flange (2) of the connecting rod facing rear of engine.
4. Position the left bank piston and connecting rod assemblies for proper installation. The arrow (1) on the top of the piston should be facing the front of the engine and the master or larger flange (2) of the connecting rod facing front of engine.
5. Install the piston, connecting rod, and upper connecting rod bearing through the top of the engine block.
6. Install the J 8037 onto the piston and compress the piston rings.
7. Use the J 8037 and lightly tap the top of the piston with a wooden hammer handle.
8. Hold the J 8037 firmly against the engine block until all of the piston rings have entered the cylinder bore.
9. Use the rubber fuel lines (1) in order to guide the connecting rod onto the crankshaft journal.
10. Remove the rubber fuel lines.
11. Install the connecting rod cap and lower connecting rod bearing.
12. Install the NEW connecting rod nuts. Tighten: Tighten the connecting rod nuts a first pass to 30 N.m (22 lb ft). Tighten the connecting rod nuts a final pass an additional 90 degrees, using the J 45059 .
13. Once the piston and connecting rod assemblies have been installed, lightly tap each connecting rod assembly, parallel to the crankpin, in order to ensure they have side clearance.
14. Use a feeler gage or a dial indicator in order to measure the side clearance between the connecting rod caps. The rod side clearance should be 0.384-0.686 mm (0.0151-0.0270 in).

Camshaft Installation

1. Lubricate the following components with clean engine oil: The camshaft lobes The camshaft bearing journals The camshaft bearings
2. Install the 3 8-1.25 x 100 mm bolts in the camshaft front bolt holes.
3. Using the bolts as a handle, install the camshaft.
4. Remove the 3 bolts from the front of the camshaft.
5. Install the camshaft retainer.
6. Install the camshaft retainer bolts. Tighten: Tighten the camshaft retainer bolts to 12 N.m (106 lb in).

Timing Chain and Sprockets Installation

1. Use the J 22102 in order to install the crankshaft sprocket. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) . Align the keyway of the crankshaft sprocket with the crankshaft pin.
2. Inspect the sprocket pin for proper installation. Refer to «Crankshaft and Bearings Cleaning and Inspection»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__crankshaft-and-bearings-cleaning-and-inspection) .
3. Rotate the crankshaft until the crankshaft sprocket alignment mark is in the 12 o'clock position.
4. Install the camshaft sprocket and timing chain.
5. Ensure the crankshaft sprocket is aligned to the 12 o'clock position and the camshaft sprocket is aligned to the 6 o'clock position.
6. Install camshaft sprocket bolts. Tighten: Tighten the camshaft sprocket bolts to 30 N.m (22 lb ft).

Engine Front Cover Installation

1. Lubricate the outer sealing surface of the crankshaft front oil seal lightly with clean engine oil. DO NOT lubricate the inner portion of the seal.
2. Position the NEW crankshaft front oil seal in the engine front cover so the mark (1) on the rear of the seal is in the 12 o'clock position. Second design oil seals do not have an alignment mark on the rear face. The seal may be installed in any position.
3. Using the J 42851 , install the crankshaft front oil seal (1). See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .
4. Install the front cover locating pins (129), if required.
5. Apply a 3-4 mm (0.12-0.16 in) bead of sealant GM P/N 12346141 (Canadian P/N 10953433), or equivalent, in 2 sealant points (1) on the engine block where the front cover meets the oil pan.
6. Apply a 3-4 mm (0.12-0.16 in) bead of sealant GM P/N 12346141 (Canadian P/N 10953433), or equivalent, in 2 sealant points (1) across the flange where the gasket ends at the bottom of the front cover.
7. Install the engine front cover gasket into the front cover.
8. Install the engine front cover. Hold the front cover (1) up to the crankshaft (2). Lift the front cover (1) while sliding the cover over the crankshaft (2). Slide the front cover towards the engine block (5) while keeping the cover raised. Lower the cover down over the dowel pin (4), allowing the front cover to rest on the sealant (3).
9. Install the engine front cover bolts. Tighten: Tighten the engine front cover bolts (1-6) in sequence a first pass to 6 N.m (53 lb in). Tighten the engine front cover bolts (1-6) in sequence a final pass to 12 N.m (106 lb in).
10. Inspect the camshaft position (CMP) sensor O-ring for cuts, cracks, tears, or damage. Replace the O-ring, as needed.
11. Apply a light film of clean engine oil to the CMP sensor O-ring.
12. Install the CMP sensor.
13. Install the CMP sensor bolt. Tighten: Tighten the CMP sensor bolt to 12 N.m (106 lb in).

Oil Pump, Screen and Crankshaft Oil Deflector Installation

1. Install the crankshaft oil deflector.
2. Install the crankshaft oil deflector nuts. Tighten: Tighten the crankshaft oil deflector nuts to 50 N.m (37 lb ft).
3. Apply clean engine oil into the oil pump through the outlet oil hole. Rotate the pump in both directions in order to prime and lubricate the pump.
4. Assemble the oil pump, driveshaft, and a NEW retainer.
5. Install the oil pump assembly. Position the oil pump onto the locating pins.
6. Install the bolt attaching the oil pump to the rear crankshaft bearing cap. Tighten: Tighten the oil pump bolt to 75 N.m (56 lb ft).
7. Pour clean engine oil into the oil pump pick-up screen.

Oil Pan Installation

1. Apply sealant GM P/N 12346141 (Canadian P/N 10953433) to the side of the front cover (1) and rear crankshaft bearing cap (2), on both the left and right sides, 4 locations total.
2. Install the new oil pan gasket (404) into the oil pan groove.
3. Install the oil pan (400).
4. Install the oil pan bolts (1-12).
5. Tighten the oil pan bolts in sequence. Tighten: Tighten the oil pan bolts (1-12) a first pass in sequence to 10 N.m (89 lb in). Tighten the oil pan bolts (1-12) a final pass in sequence to 25 N.m (18 lb ft).
6. Install the oil pan drain plug. Tighten: Tighten the oil pan drain plug to 28 N.m (21 lb ft).
7. Lubricate the oil level sensor O-ring with engine oil.
8. Install the oil level sensor. Tighten: Tighten the oil level sensor to 20 N.m (15 lb ft).

Oil Pump Drive Installation

1. Apply grease to the oil pump drive gear for ease of assembly.
2. Line up the oil pump drive gear with the oil pump driveshaft.
3. Install the oil pump drive. Ensure the oil pump drive is fully seated in the engine block.
4. Install the oil pump drive bolt. Tighten: Tighten the oil pump drive bolt to 25 N.m (18 lb ft).

Valve Lifter Installation

1. Apply clean engine oil to the valve lifter rollers.
2. Install the valve lifters.
3. Install the valve lifter guides over the flats on the valve lifters. Ensure the rollers of the valve lifters are properly aligned with the camshaft lobes.
4. Install the valve lifter guide retainer.
5. Install the valve lifter guide retainer bolts. Tighten: Tighten the valve lifter guide retainer bolts to 25 N.m (18 lb ft).

Cylinder Head Installation - Left Side

1. Place the cylinder head gasket in position over the cylinder head locating pins.
2. Install the cylinder head to the block.
3. If not pre-applied to the new cylinder head bolts (227, 228, 229), apply sealer GM P/N 12346004 (Canadian P/N 10953480), or equivalent, to the cylinder head bolts. Refer to «Sealers, Adhesives, and Lubricants»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__sealers-adhesives-and-lubricants) .
4. Install the cylinder head bolts. Tighten: Tighten the bolts (1-18) a first pass in sequence to 30 N.m (22 lb ft). Tighten the bolts (1-18) a second pass in sequence to 30 N.m (22 lb ft), then an additional 120 degrees, using the J 45059 . Tighten the bolts, 1, 2, 3, 6, 7, 8, 9, 10, 11, 14, 16, 17, an additional 60 degrees, bolts 15 and 18 an additional 45 degrees, and bolts, 4, 5, 12, 13, an additional 30 degrees a final pass in sequence, using the J 45059 .

Cylinder Head Installation - Right Side

1. Place the cylinder head gasket in position over the cylinder head locating pins.
2. Install the cylinder head to the block.
3. If not pre-applied to the new cylinder head bolts (227, 228, 229), apply sealer GM P/N 12346004 (Canadian P/N 10953480), or equivalent, to the cylinder head bolts. Refer to «Sealers, Adhesives, and Lubricants»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__sealers-adhesives-and-lubricants) .
4. Install the cylinder head bolts. Tighten: Tighten the bolts (1-18) a first pass in sequence to 30 N.m (22 lb ft). Tighten the bolts (1-18) a second pass in sequence to 30 N.m (22 lb ft), then an additional 120 degrees, using the J 45059 . Tighten the bolts, 1, 2, 3, 6, 7, 8, 9, 10, 11, 14, 16, 17, an additional 60 degrees, bolts 15 and 18 an additional 45 degrees, and bolts, 4, 5, 12, 13, an additional 30 degrees a final pass in sequence, using the J 45059 .

Valve Rocker Arm and Push Rod Installation

1. Apply sealer GM P/N 12346004 (Canadian P/N 10953480), or equivalent, to the valve rocker arm stud-to-cylinder head threads. Apply the sealer to a minimum of 6 threads.
2. Install the push rod guides and valve rocker arm studs onto the cylinder head. Tighten: Tighten the valve rocker arm studs to 50 N.m (37 lb ft).
3. Install the valve push rods.
4. Apply grease or clean engine oil to the valve rocker arm and valve rocker arm ball bearing surface.
5. Install the valve rocker arms, the valve rocker arm balls, and the valve rocker arm nuts. Tighten: Tighten the valve rocker arm nuts slowly to 35 N.m (26 lb ft), while guiding the tips of the rocker arms over the tips of the valves.

Intake Manifold Installation

1. Install the splash shield.
2. Ensure the splash shield (2) snap fits between the cylinder heads (1).
3. Apply a 5 mm (0.2 in) bead of GM P/N 12346141 (Canadian P/N 10953433) sealer (1) to the 4 engine block/cylinder head locations.
4. Install the new intake manifold end seals.
5. Apply a 5 mm (0.2 in) bead of GM P/N 12346141 (Canadian P/N 10953433) sealer (1) onto the end seals at the 4 engine block/cylinder head locations.
6. Install the new intake manifold side gaskets onto the cylinder heads.
7. Ensure the intake manifold gasket tabs align with the hole in the head gasket.
8. Ensure the intake manifold gasket tabs align with the slot in the intake manifold end seals.
9. Install the intake manifold onto the engine block.
10. Install the NEW intake manifold bolts.
11. Tighten the intake manifold bolts (1-10) in sequence, using 4 passes. Tighten: Tighten the intake manifold bolts a first pass in sequence to 5 N.m (44 lb in). Tighten the intake manifold bolts a second pass in sequence to 8 N.m (71 lb in). Inspect the intake manifold joints for signs of intake manifold shifting. Correct, as required. Tighten the intake manifold bolts a third pass in sequence to 12 N.m (106 lb in). Tighten the intake manifold bolts a final pass in sequence to 15 N.m (11 lb ft).
12. Install the fuel injection fuel rail with injectors.
13. Install the fuel injection fuel rail bolts/studs. Tighten: Tighten the fuel injection fuel rail bolts/studs to 12 N.m (106 lb in).
14. Install the throttle body gasket (501) and throttle body (502).
15. Install the throttle body nuts (503). Tighten: Tighten the throttle body nuts to 10 N.m (89 lb in).
16. Install the vacuum plug (513).

Valve Rocker Arm Cover Installation - Left Side

1. Install a new valve rocker arm cover gasket if the gasket was removed from the valve rocker arm cover.
2. Install the valve rocker arm cover.
3. Install the valve rocker arm cover bolts.
4. Tighten the valve rocker arm cover bolts (1-7) in sequence, using 2 passes. Tighten: Tighten the valve rocker arm cover bolts (1-7) a first pass to 6 N.m (54 lb in). Tighten the valve rocker arm cover bolts (1-7) a final pass to 12 N.m (106 lb in).

Valve Rocker Arm Cover Installation - Right Side

1. Install a new valve rocker arm cover gasket if the gasket was removed from the valve rocker arm cover.
2. Install the valve rocker arm cover.
3. Install the valve rocker arm cover bolts.
4. Tighten the valve rocker arm cover bolts (1-7) in sequence, using 2 passes. Tighten: Tighten the valve rocker arm cover bolts (1-7) a first pass to 6 N.m (54 lb in). Tighten the valve rocker arm cover bolts (1-7) a final pass to 12 N.m (106 lb in).

Water Pump Installation

1. Install the water pump and gaskets.
2. Install the water pump bolts. Tighten: Tighten the water pump bolts (1-4) a first pass in sequence to 25 N.m (18 lb ft). Tighten the water pump bolts (1-4) a final pass in sequence to 50 N.m (37 lb ft).
3. Install the water pump pulley (303) and bolts (302).
4. Use the J 41240 in order to retain the water pump pulley. Tighten: Tighten the water pump pulley bolts to 25 N.m (18 lb ft).

Water Crossover Installation

1. Install the thermostat (312) with the seal into the engine coolant crossover (308).
2. Install the water outlet (311).
3. Install the water outlet bolts (310). Tighten: Tighten the bolts to 30 N.m (22 lb ft).
4. Install the gaskets and the engine coolant crossover.
5. Install the bolts. Tighten: Tighten the engine coolant crossover bolts to 50 N.m (37 lb ft).
6. Install the thermostat bypass hose and clamps.
7. Install the drive belt tensioner.
8. Install the drive belt tensioner bolts. Tighten: Tighten the drive belt tensioner bolts to 50 N.m (37 lb ft).

Exhaust Manifold Installation - Left Side

1. Install the exhaust manifold studs into the cylinder head, if necessary. Tighten: Tighten the exhaust manifold studs to 20 N.m (15 lb ft).
2. Install the NEW left exhaust manifold gasket.
3. Install the left exhaust manifold.
4. Install the left exhaust manifold nuts and center bolt. Tighten: Tighten the left exhaust manifold center bolt to 35 N.m (26 lb ft). Tighten the left exhaust manifold nuts to 16 N.m (12 lb ft).
5. Install the left exhaust manifold heat shield.
6. Install the left exhaust manifold heat shield bolts and nuts. Tighten: Tighten the left exhaust manifold heat shield bolts and nuts to 25 N.m (18 lb ft).
7. Install the spark plugs. Tighten: Tighten the spark plugs to 30 N.m (22 lb ft).
8. Install the spark plug wires to the spark plugs and ignition coils.

Exhaust Manifold Installation - Right Side

1. Install the exhaust manifold studs into the cylinder head, if necessary. Tighten: Tighten the exhaust manifold studs to 20 N.m (15 lb ft).
2. Install the NEW right exhaust manifold gasket.
3. Install the right exhaust manifold.
4. Install the right exhaust manifold nuts and center bolt. Tighten: Tighten the right exhaust manifold center bolt to 35 N.m (26 lb ft). Tighten the right exhaust manifold nuts to 16 N.m (12 lb ft).
5. Install the right exhaust manifold heat shield.
6. Install the right exhaust manifold heat shield bolts and nuts. Tighten: Tighten the right exhaust manifold heat shield bolts and nuts to 25 N.m (18 lb ft).
7. Install the spark plugs. Tighten: Tighten the spark plugs to 30 N.m (22 lb ft).
8. Install the spark plug wires to the spark plugs and ignition coils.

Oil Level Indicator and Tube Installation

1. Install a NEW O-ring seal onto the oil level indicator tube.
2. Install the oil level indicator tube into the oil pan.
3. Install the oil level indicator tube bracket to the exhaust manifold stud.
4. Install the oil level indicator tube bracket bolt. Tighten: Tighten the oil level indicator tube bolt to 25 N.m (18 lb ft).
5. Install the oil level indicator into the oil level indicator tube.

Clutch Pilot Bearing Installation

1. Install the NEW clutch pilot bearing.
2. Measure to ensure the proper installation depth is obtained. The bearing (138) should be 14.650-15.650 mm (0.577-0.616 in) (a) from the lip of the crankshaft or 6.400-7.400 mm (0.252-0.291 in) (b) from the crankshaft flange.

Crankshaft Rear Oil Seal Installation

1. Make sure the crankshaft rear chamfer is free of grit, loose rust, and burrs. Correct as needed.
2. Apply a very light film of oil onto the crankshaft sealing surface. DO NOT apply oil to the sealing surface of the engine block.
3. Install the seal on the J 42849 . See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .
4. Position J 42849 against the crankshaft. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) . Thread the attaching screws into the tapped holes in the crankshaft.
5. Tighten the screws securely with a screwdriver in order to ensure that the seal is installed squarely over the crankshaft.
6. Rotate the center nut until the J 42849 bottoms. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .
7. Remove the J 42849 . See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .

Engine Flywheel Installation (Automatic Transmission)

1. Install the engine flex plate.
2. Install the engine flex plate bolts. Tighten the bolts following a criss-cross pattern. Tighten: Tighten the engine flex plate bolts a first pass to 40 N.m (30 lb ft). Tighten the engine flex plate bolts a second pass to 80 N.m (59 lb ft). Tighten the engine flex plate bolts a final pass to 100 N.m (74 lb ft).

Engine Flywheel Installation (Manual Transmission)

1. Install the engine flywheel.
2. Install the engine flywheel bolts. Tighten the bolts following a criss-cross pattern. Tighten: Tighten the engine flywheel bolts a first pass to 40 N.m (30 lb ft). Tighten the engine flywheel bolts a second pass to 80 N.m (59 lb ft). Tighten the engine flywheel bolts a final pass to 100 N.m (74 lb ft).

Crankshaft Balancer Installation

Tools Required

1. J 42845 Crankshaft Balancer Installer. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .
2. J 42847 Flywheel Holding Tool. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .

1. Install the J 42847 (1) to the starter bolt holes. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) . Tighten: Tighten the J 42847 bolts to 50 N.m (37 lb ft).
2. Install the balancer onto the end of the crankshaft.
3. Use the J 42845 (1) in order to install the balancer. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .
4. Tighten the J 42845 until the crankshaft balancer is completely seated against the crankshaft sprocket. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .
5. Remove the J 42845 from the crankshaft. See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .
6. Install the crankshaft balancer washer and bolt. Tighten: Tighten the crankshaft balancer bolt to 255 N.m (189 lb ft).
7. Remove the J 42847 (1). See «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .

Engine Prelubing

1. Remove the engine oil filter and fill with clean engine oil.
2. Install the oil filter. Tighten: Tighten the oil filter to 38 N.m (28 lb ft).
3. Locate the oil gallery plug on the left side of the engine block above the oil filter housing.
4. Install the 1/4 - 18 adapter P/N 509373.
5. Install the flexible hose to the adapter and open the valve.
6. Pump the handle on the J 45299 in order to flow a minimum of 1-1.9 liters (1-2 quarts) of engine oil. Observe the flow of engine oil through the flexible hose and into the engine assembly.
7. Close the valve and remove the flexible hose and adapter from the engine.
8. Install the gallery plug to the engine. Tighten: Tighten the oil gallery plug to 30 N.m (22 lb ft).
9. Top-off the engine oil to the proper level.

Crankcase Ventilation System Description

The crankcase ventilation system has no serviceable components so routine maintenance of the system is not required.

A closed crankcase ventilation system is used in order to provide a more complete scavenging of crankcase vapors. The air cleaner supplies the fresh air through a filter to the crankcase. The crankcase mixes the fresh air blow-by gases. This mixture then passes through a pipe/passage located in the intake manifold.

Drive Belt System Description

The drive belt system consists of the following components

1. The drive belt
2. The drive belt tensioner
3. The drive belt idler pulley
4. The crankshaft balancer pulley
5. The accessory drive component mounting brackets
6. The accessory drive components The power steering pump, if belt driven The generator The A/C compressor, if equipped The engine cooling fan, if belt driven The water pump, if belt driven The vacuum pump, if equipped The air compressor, if equipped

The drive belt system may use 1 belt or 2 belts. The drive belt is thin so that it can bend backwards and has several ribs to match the grooves in the pulleys. The drive belts are made of different types of rubbers, chloroprene or EPDM, and have different layers or plys containing either fiber cloth or cords for reinforcement.

Both sides of the drive belt may be used to drive the different accessory drive components. When the back side of the drive belt is used to drive a pulley, the pulley is smooth.

The drive belt is pulled by the crankshaft balancer pulley across the accessory drive component pulleys. The spring loaded drive belt tensioner keeps constant tension on the drive belt to prevent the drive belt from slipping. The drive belt tensioner arm will move when loads are applied to the drive belt by the accessory drive components and the crankshaft.

The drive belt system may have an idler pulley, which is used to add wrap to the adjacent pulleys. Some systems use an idler pulley in place of an accessory drive component when the vehicle is not equipped with the accessory.

Scheme 129

Cylinder Block

The engine block is made of cast iron and it has 8 cylinders arranged in a 90 degree V shape with 4 cylinders in each bank. The engine block is a 1 piece casting with the cylinders encircled by coolant jackets.

Cylinder Head

The cylinder heads are made of cast iron and have parent metal intake valve guides and intake valve seats. The cast iron exhaust valve guides and powdered metal valve seats are pressed into the exhaust ports. A spark plug is located between the valves in the side of the cylinder head. The engine coolant crossover attaches to the front of each cylinder head.

Camshaft

A steel camshaft is supported by 5 bearings pressed into the engine block. The camshaft sprocket is mounted to the front of the camshaft and is driven by the crankshaft sprocket through the timing chain.

Motion from the camshaft is transmitted to the valves by hydraulic roller valve lifters, valve push rods, and ball-type rocker arms. Gear teeth are machined into the camshaft near the rear journal in order to drive a shaft assembly which operates the oil pump driveshaft. The camshaft position (CMP) sensor reads a circular target, half raised and half lowered, that is integral to the camshaft sprocket. The CMP sensor signal is used by the powertrain control module (PCM) for start-up only.

Crankshaft

The crankshaft is made of cast nodular iron. The crankshaft is supported by 5 crankshaft bearings. The crankshaft bearings are retained by the crankshaft bearing caps. The crankshaft bearing caps are machined with the engine block for proper alignment and clearance. The crankshaft bearing caps are each retained by 2 bolts and 2 studs. The number 5 crankshaft bearing at the rear of the engine block is the end thrust bearing. The 4 connecting rod journals, 2 rods per journal, are spaced 90 degrees apart. The crankshaft position (CKP) sensor reluctor ring is pushed onto the rear of the crankshaft. The CKP sensor reluctor is constructed of powdered metal. The reluctor ring has an interference fit onto the crankshaft and an internal keyway for correct positioning.

Pistons and Connecting Rods

The pistons are cast aluminum and use 2 compression rings and 1 3-piece oil control ring assembly. The piston pins are a full-floating design. The piston skirts are coated in order to create an interference fit into the cylinder bore. The connecting rods are forged steel and have precision insert type crankshaft bearings. The piston and pin are to be serviced as an assembly.

Valve Train

The valve train is a ball pivot type. Motion is transmitted from the camshaft through the hydraulic roller valve lifters and tubular valve push rods to the valve rocker arms. The valve rocker arm pivots on a ball in order to open the valve. The hydraulic roller valve lifters keep all parts of the valve train in constant contact. Each valve lifter acts as an automatic adjuster and maintains zero lash in the valve train. This eliminates the need for periodic valve adjustment. The valve rocker arm stud and nut retains the valve rocker arm and ball seat. The valve rocker arm stud is threaded into the cylinder head. The valve stem seal is pressed onto the valve guide of the cylinder head.

Intake Manifold

The intake manifold is a 1-piece cast aluminum design. The throttle body is attached to the front of the intake manifold. The fuel rail assembly with 8 separate fuel injectors is retained to the intake manifold by 4 studs. The fuel injectors are seated in their individual manifold bores with O-ring seals to provide sealing. A Manifold Absolute Pressure (MAP) sensor is mounted on the top of the intake manifold and sealed by an O-ring seal. The MAP sensor is held in place with a retainer bolt. The evaporative emission (EVAP) canister purge solenoid valve is located in the front of the intake manifold. The positive crankcase ventilation (PCV) system is internally cast into the intake manifold. There is no serviceable PCV valve. A splash shield is installed under the intake manifold. The shield prevents hot oil from contacting the bottom of the intake manifold.

Exhaust Manifold

The exhaust manifolds are constructed of cast stainless steel. The exhaust manifolds direct exhaust gases from the combustion chambers to the exhaust system.

New Product Information

The purpose of New Product Information is to highlight important technical changes from the previous model year.

Changes may include 1 or more of the following items

1. Torque values and/or fastener tightening strategies
2. Changed engine specifications
3. New sealants and/or adhesives
4. Disassembly and assembly procedure revisions
5. Engine mechanical diagnostic procedure revisions
6. New special tools required
7. A component comparison from the previous year

Torque Values and/or Fastener Tightening Strategies

No torque or fastener tightening changes from the previous year. Refer to Fastener Tightening Specifications .

Changed Engine Specifications

No changed engine specifications. Refer to Engine Mechanical Specifications .

New Sealants and/or Adhesives

No sealant or adhesive changes from the previous year. Refer to Sealers, Adhesives, and Lubricants .

Engine Mechanical Diagnostic Procedure Revisions

All diagnosis on a vehicle should follow a logical process. Strategy based diagnostics is a uniform approach for repairing all systems. The diagnostic flow may always be used in order to resolve a system condition. The diagnostic flow is the place to start when repairs are necessary. For a detailed explanation, refer to Strategy Based Diagnosis or Diagnostic Starting Point - Engine Mechanical .

New Special Tools Required

1. A variety of new tools have been developed to assist in engine disassembly, assembly, and on-vehicle service. Refer to «Special Tools»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l__special-tools) .
2. Angle meter J 45059 has been developed to provide technicians with a convenient method to tighten bolts that require the torque angle tightening strategy.

A Component Comparison from the Previous Year

1. The exhaust gas recirculation system (EGR) has been removed. Refer to «Disassembled Views»(/chevrolet/cab-chassis-silverado-3500/2003-2012/remont/mechanical/#engine-mechanical-81l) .
2. The front cover is now aligned to the engine block with 2 front cover locating pins.
3. All applications use a full-floating design piston and pin assembly.

Scheme 130

The gear-type oil pump is driven through an extension driveshaft. The extension driveshaft is driven by the oil pump drive, which is gear driven by the camshaft. The oil is drawn from the oil pan through a pickup screen and tube, into the oil pump (7). Pressurized oil flows through the oil filter, into the oil cooler (5), back into the engine (6), up to the oil pressure gage port (2) and rear crankshaft bearing, and is then distributed to the upper oil galleries. Oil must flow around the oil pump drive (1) in order to reach the right side valve lifters properly. The oil is delivered through internal passages in order to lubricate camshaft and crankshaft bearings and to provide lash control in the hydraulic valve lifters. Oil is metered from the valve lifters through the valve push rods in order to lubricate the valve rocker arms and ball pivots. Oil returning to the oil pan from the cylinder heads and the front camshaft bearing, lubricates the camshaft timing chain and the crankshaft and the camshaft sprockets. There are two bypass valves located in the engine block, above the oil filter. The oil filter bypass valve (4) and the oil cooler bypass valve (3).

Scheme 131

If the oil filter becomes plugged, the pressurized oil is diverted around the top of the oil filter. The oil filter bypass valve (1) is forced open, allowing the oil to continue on to the oil cooler and engine oil passages. No oil filtration occurs because the oil is not allowed into the oil filter.

Scheme 132

If the oil cooler flow becomes blocked, either from a plugged oil cooler or blocked or kinked oil cooler line, the oil cooler bypass valve (1) is forced open, allowing oil to flow directly into the engine oil passages. Oil does not flow into or out of the engine oil cooler.

Scheme 133

If both the oil filter and the oil cooler are plugged, the pressurized oil is routed around the top of the oil filter, through the oil filter bypass valve (2), through the oil cooler bypass valve (1) and directly into the engine oil passages. Lubrication still occurs, but the oil is not filtered or directed through the oil cooler.

Cleanliness and Care

1. Throughout this section, it should be understood that proper cleaning and protection of machined surfaces and friction areas is part of the repair procedure. This is considered standard shop practice even if not specifically stated.
2. When any internal engine parts are serviced, care and cleanliness is important.
3. When components are removed for service, they should be marked, organized or retained in a specific order for reassembly.
4. At the time of installation, components should be installed in the same location and with the same mating surface as when removed.
5. An automobile engine is a combination of many machined, honed, polished and lapped surfaces with tolerances that are measured in millimeters or thousandths of an inch. These surfaces should be covered or protected to avoid component damage.
6. A liberal coating of clean engine oil should be applied to friction areas during assembly.
7. Proper lubrication will protect and lubricate friction surfaces during initial operation.

Separating Parts

Separate, mark, or organize the following components

1. Piston to the specific cylinder bore
2. Piston rings to the piston
3. Connecting rod to the crankshaft journal
4. Connecting rod to the bearing cap
5. Crankshaft and connecting rod bearings
6. Camshaft and valve lifters
7. Valve lifters, guides, pushrods, pivot supports and rocker arms
8. Valve to the valve guide
9. Valve spring and shim to the cylinder head location
10. Engine block crankshaft bearing cap location and direction
11. Oil pump drive and driven gears

Gasket Reuse and Applying Sealant

1. Do not reuse any gasket unless specified.
2. Gaskets that can be reused will be identified in the service procedure.
3. Do not apply sealant to any gasket or sealing surface unless specified in the service procedure.

Separating Components

1. Use a rubber mallet in order to separate the components.
2. Bump the part sideways in order to loosen the components.
3. Bumping of the component should be done at bends or reinforced areas of the component to prevent distortion of the components.

Cleaning Gasket Surfaces

1. Use care to avoid gouging or scraping the sealing surfaces.
2. Use a plastic or wood scraper in order to remove all the sealant from the components. Do not use any other method or technique to remove the sealant or the gasket material from a part.
3. Do not use abrasive pads, sand paper, or power tools to clean the gasket surfaces. These methods of cleaning can cause damage to the component sealing surfaces. Abrasive pads also produce a fine grit that the oil filter cannot remove from the engine oil. This fine grit is an abrasive and can cause internal engine damage.

Assembling Components

1. Assemble components using only the sealant (or equivalent) that is specified in the service procedure.
2. Sealing surfaces must be clean and free of debris or oil.
3. Specific components such as crankshaft oil seals or valve stem oil seals may require lubrication during assembly.
4. Components requiring lubrication will be identified in the service procedure.
5. Apply only the amount of sealant specified in the service procedure to a component.
6. Do not allow the sealant to enter into any blind threaded holes, as the sealant may prevent the fastener from clamping properly or cause component damage when tightened.
7. Tighten the fasteners to the proper specifications.

Sealant Types

The following 2 major types of sealant are commonly used in engines

1. Aerobic room temperature vulcanizing (RTV) sealant
2. Anaerobic sealant, which include the following: Gasket eliminator Pipe Threadlock

RTV Sealant

Aerobic type RTV sealant cures when exposed to air. This type of sealant is used where 2 components, such as the intake manifold and the engine block, are assembled together.

Use the following information when using RTV sealant

1. Do not use RTV sealant in areas where extreme temperatures are expected. These areas include: The exhaust manifold The head gasket Any other surfaces where a different type of sealant is specified in the service procedure
2. Always follow all safety recommendations and the directions that are on the RTV sealant container.
3. Use a plastic or wood scraper in order to remove all RTV sealant from the plastic and aluminum components.
4. The surfaces to be sealed must be clean and dry.
5. Use an RTV sealant bead size as specified in the service procedure.
6. Apply the RTV sealant bead to the inside of any bolt holes areas.
7. Assemble the components while the RTV sealant is still wet to the touch, within 3 minutes. Do not wait for the RTV sealant to skin over.
8. Tighten the fasteners in sequence, if specified, and to the proper torque specifications. DO NOT overtighten the fasteners.

Gasket Eliminator Sealant

Anaerobic type gasket eliminator sealant cures in the absence of air. This type of sealant is used where 2 rigid components, such as castings, are assembled together. When 2 rigid components are disassembled and no sealant or gasket is readily noticeable, the 2 parts were probably assembled using an anaerobic type gasket eliminator sealant.

Use the following information when using gasket eliminator sealant

1. Always follow all safety recommendations and directions that are on the gasket eliminator sealant container.
2. Apply a continuous bead of gasket eliminator sealant to 1 flange. The surfaces to be sealed must be clean and dry.
3. Apply the gasket eliminator sealant evenly to get a uniform thickness of the gasket eliminator sealant on the sealing surface.
4. Tighten the fasteners in sequence, if specified, and to the proper torque specifications. DO NOT overtighten the fasteners.
5. After properly tightening the fasteners, remove the excess gasket eliminator sealant from the outside of the joint.

Threadlock Sealant

Anaerobic type threadlock sealant cures in the absence of air. This type of sealant is used for threadlocking and sealing of bolts, fittings, nuts, and studs. This type of sealant cures only when confined between 2 close fitting metal surfaces.

Use the following information when using threadlock sealant

1. Always follow all safety recommendations and directions that are on the threadlock sealant container.
2. The threaded surfaces to be sealed must be clean and dry.
3. Apply the threadlock sealant as specified on the threadlock sealant container.
4. Tighten the fasteners in sequence, if specified, and to the proper torque specifications. DO NOT overtighten the fasteners.

Pipe Sealant

Anaerobic type pipe sealant cures in the absence of air and remains pliable when cured. This type of sealant is used where 2 components are assembled together and require a leak proof joint.

Use the following information when using pipe sealant

1. Do not use pipe sealant in areas where extreme temperatures are expected. These areas include: The exhaust manifold The head gasket Surfaces where a different sealant is specified
2. Always follow all safety recommendations and the directions that are on the pipe sealant container.
3. The surfaces to be sealed must be clean and dry.
4. Use a pipe sealant bead of the size or quantity as specified in the service procedure.
5. Apply the pipe sealant bead to the inside of any bolt hole areas.
6. Apply a continuous bead of pipe sealant to 1 sealing surface.
7. Tighten the fasteners in sequence, if specified, and to the proper torque specifications. DO NOT overtighten the fasteners.

Tools and Equipment

1. Special tools are listed and illustrated throughout this section, with a complete listing at the end of the section. These tools, or their equivalents, are designed to quickly and safely accomplish the operations for which they are intended. The use of these special tools also minimize possible damage to engine components. Some precision measuring tools are required for inspection of certain critical components. Torque wrenches and a torque angle meter are necessary for the proper tightening of various fasteners.
2. To properly service the engine assembly, the following items should be readily available: Approved eye protection and safety gloves A clean, well-lit, work area A suitable component cleaning tank A compressed air supply Trays or storage containers to keep components and fasteners organized An adequate set of hand tools Approved engine repair stand An approved engine lifting device that adequately supports the weight of the components

Special Tools

Special Tools Illustration Tool Number/Description GE-48326 Sealant Dispenser J 3049-A Valve Lifter Remover J 5892-D Valve Spring Compressor J 7872 Magnetic Base Dial Indicator J 8001 Dial Indicator Set J 8037 Piston Ring Compressor J 8062 Valve Spring Compressor - Head Off J 8087 Cylinder Bore Gage J 8089 Carbon Removal Brush J 9666 Valve Spring Tester J 22102 Front Cover Aligner and Seal Installer J 22794 Spark Plug Port Adapter J 24270 Cylinder Bore Ridge Reamer J 28428-E High Intensity Black Light J 33049 Camshaft Bearing Service Set J 35667-A Cylinder Head Leakdown Tester J 36857 Engine Lift Bracket J 38416-B Harmonic Balancer Remover J 41240 Fan Clutch Remover and Installer J 41712 Oil Pressure Switch Socket J 42385-200 Common Thread Repair Kit J 42845 Crankshaft Balancer Installer J 42846 Crankshaft Protector Button J 42847 Flywheel Holding Tool J 42849 Crankshaft Rear Seal Installer J 42851 Front Cover Oil Seal Installer J 43105 Valve Stem Seal Installer J 43276 Clutch Pilot Bearing Remover J 43320 Crankshaft Rear Seal Puller J 43690 Rod Bearing Clearance Checking Tool J 43690-100 Rod Bearing Clearance Checking Tool - Adapter Kit J 45059 Angle Meter J 45299 Engine Preluber

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Scheme 154

See also:
• Diagnostic System Check - Vehicle
• Strategy Based Diagnosis
• Checking Aftermarket Accessories
• Spark Plug Inspection
• Loss of Coolant
• Detonation/Spark Knock
• Battery Disconnect Caution
• Spark Plug Replacement
• Belt Dressing Notice
• Fastener Notice
• Vibration Analysis - Engine
• Water Pump Replacement (8.1L)
• Tire and Wheel Removal and Installation
• Metal Collar Quick Connect Fitting Service
• Exhaust Manifold Replacement - Left Side (8.1L Engine)
• Draining and Filling Cooling System (Static Fill)
• Draining and Filling Cooling System (w/RPO HP2)
• Draining and Filling Cooling System (Vac-N-Fill)
• Starter Motor Replacement (8.1L Engine)
• Grille Replacement (Chevrolet)
• Condenser Replacement
• Differential Carrier Assembly Replacement
• Transmission Replacement (8.1L)
• Clutch Assembly Replacement
• Lifting and Jacking the Vehicle
• Power Steering Cooler Pipe/Hose Replacement (Rack and Pinion)
• Transmission Replacement
• Crankshaft Position System Variation Learn
• Fluid and Lubricant Recommendations
• Safety Glasses Caution
• Sealant Notice
• Disassembled Views
• New Product Information
• Base Engine Misfire without Internal Engine Noises
• Base Engine Misfire with Abnormal Internal Lower Engine Noises
• Base Engine Misfire with Abnormal Valve Train Noise
• Base Engine Misfire with Coolant Consumption
• Base Engine Misfire with Excessive Oil Consumption
• Engine Noise on Start-Up, but Only Lasting a Few Seconds
• Upper Engine Noise, Regardless of Engine Speed
• Lower Engine Noise, Regardless of Engine Speed
• Engine Noise Under Load
• Engine Will Not Crank - Crankshaft Will Not Rotate
• Coolant in Combustion Chamber
• Coolant in Engine Oil
• Engine Compression Test
• Cylinder Leakage Test
• Oil Consumption Diagnosis
• Oil Pressure Diagnosis and Testing
• Crankshaft Balancer Replacement
• Cylinder Head Cleaning and Inspection
• Fastener Tightening Specifications
• Drive Belt Tensioner Diagnosis
• Sealers, Adhesives, and Lubricants
• Intake Manifold Disassemble
• Intake Manifold Cleaning and Inspection
• Intake Manifold Assemble
• Valve Rocker Arm Cover Cleaning and Inspection
• Valve Rocker Arm and Push Rods Cleaning and Inspection
• Special Tools
• Valve Lifters and Guides Cleaning and Inspection
• Timing Chain and Sprockets Cleaning and Inspection
• Oil Pump Drive Cleaning and Inspection
• Timing Chain and Sprockets Replacement
• Camshaft and Bearings Cleaning and Inspection
• Oil Pump Cleaning and Inspection
• Engine Flywheel Cleaning and Inspection (Automatic Transmission)
• Engine Flywheel Cleaning and Inspection (Manual Transmission)
• Engine Prelubing
• Crankshaft and Bearings Cleaning and Inspection
• Engine Mechanical Specifications
• Crankshaft and Bearings Installation
• Piston, Connecting Rod, and Bearing Installation
• Camshaft Bearing Removal
• Engine Block Cleaning and Inspection
• Piston, Connecting Rod, and Bearings Cleaning and Inspection
• Diagnostic Starting Point - Engine Mechanical