Engine Mechanical - 4.3L (Unit Repair): Other GMC Sierra 2500

Boring Procedure

1. Before starting the honing or reboring operation, measure all the new pistons with the micrometer contacting at points exactly 90 degrees from the piston pin centerline.
2. File the top of the cylinder block in order to remove any dirt or burrs before using any type of boring bar.
3. Follow the instructions furnished by the manufacturer regarding use of the boring equipment.
4. When reboring the cylinders, make sure all the crankshaft bearing caps are installed in the original position and direction.
5. Tighten the crankshaft bearing caps to the proper torque specifications in order to avoid distortion of the cylinder bores in the final assembly.
6. When making the final cut with the boring bar, leave 0.03 mm (0.001 in) on the cylinder bore 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 the pistons, the piston rings, and the cylinder bores.

Measuring Crankshaft Bearing Clearances

1. The crankshaft bearings are of the precision insert type and do not use shims for adjustment. If the clearances are excessive, then new upper and lower crankshaft bearings will be required.

The service crankshaft bearings are available in the standard size and an undersize.

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1. The selective fitting of the crankshaft bearings are necessary in production in order to obtain close tolerances. For this reason, in one journal bore you may use one-half of a standard crankshaft bearing with one-half of an undersize crankshaft bearing.
2. In order to determine the correct replacement bearing size, the bearing clearance must be measured accurately. When checking main bearing clearances, either the micrometer or plastic gage method may be used; however, the micrometer method gives more reliable results and is preferred. When checking connecting rod bearing clearances, the plastic gage method will result in unreliable measurements. The use of J 43690 is preferred.
3. Normally the crankshaft bearing journals wear evenly and are not out-of-round. However, if a crankshaft bearing is being fitted to an out-of-round crankshaft bearing journal, be sure to fit to the maximum diameter of the crankshaft bearing journal. If the crankshaft bearing is fitted to the minimum diameter and the crankshaft bearing journal is excessively out-of-round, the interference between the crankshaft bearing and the crankshaft bearing journal will result in rapid crankshaft bearing failure.
4. If the crankshaft bearing clearance is within specifications, the crankshaft bearing is satisfactory. If the clearance is not within specifications, replace the crankshaft bearing. Always replace both the upper and lower crankshaft bearings as a set.
5. A standard or undersize crankshaft bearing combination may result in the proper clearance. If the proper crankshaft bearing clearance cannot be achieved using the standard or the undersize crankshaft bearings, it may be necessary to repair or replace the crankshaft.

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1. Measure the crankshaft journal diameter with a micrometer in several places, approximately 90 degrees apart. Average the measurements.
2. Determine the taper and out-of-round of the journal. Refer to «Engine Mechanical Specifications»(ref-176270-S25975192972005050300000) .
3. Install the bearings into the engine block or connecting rod assembly.
4. Install the bearing cap bolts and tighten to specifications. Refer to «Fastener Tightening Specifications»(ref-176270-S00946143732005050300000) .
5. Measure the bearing inside diameter (ID) at two points 90 degrees apart. Average the measurements.
6. In order to determine the bearing clearance, subtract the average journal diameter from the average bearing inside diameter.
7. Compare the readings to specifications. Refer to «Engine Mechanical Specifications»(ref-176270-S25975192972005050300000) .
8. Replace bearing halves as required to obtain the proper bearing clearances.

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1. Remove the oil pan and other necessary components to gain access to the connecting rods. Remove the oil pump, screen, and deflector, when applicable.
2. Rotate the crankshaft until the crankshaft journal/connecting rod to be measured is in the 10 o'clock position. Important: The crankshaft must be secure with no movement or rotation in order to obtain an accurate reading. Remove an intermediate bearing cap, as required, in order to secure the crankshaft and allow measurement of connecting rod bearing clearances.
3. Remove the bearing cap bolts, cap and bearing half.
4. Insert a piece of paper card stock onto the crankshaft journal. Install the bearing half, bearing cap, and bolts. Refer to «Fastener Tightening Specifications»(ref-176270-S00946143732005050300000) .
5. Install the foot (1) and bolt (2) to the pivot arm assembly (3). Tighten the bolt until snug.
6. Install the screw (1 or 3) to the pivot arm assembly (2).
7. Install the pivot arm assembly (1) onto the connecting rod.
8. Position the foot of the pivot arm assembly over the large end of the connecting rod bolt.
9. Position the screw (1) onto the small end of the connecting rod bolt and tighten securely.
10. Install the base (1) and bolt (2) to the oil pan rail.
11. Install the base (1) and bolt (2) to the oil pan rail. Tighten the bolt (2) until snug.
12. Align the link (1) of the pivot arm assembly on a plane (3) equal to that of the connecting rod beam (2).
13. With the link of the pivot arm assembly aligned to the beam of the connecting rod, position the pivot arm to the base and insert the pin (1).
14. Insert the handle (1) to the pivot arm assembly.
15. Select the adapter (2), as required, and install to the swivel base (1). Tighten until snug. Important: The clamp of the swivel base and the shaft of the indicator should be free of oil or other debris. A loose or improperly clamped indicator may indicate incorrect readings.
16. Install the indicator (2) to the swivel base (1). Tighten the clamp of the base until snug.
17. Install the swivel base (1) to the oil pan rail of the engine block. Tighten until snug.
18. Adjust the swivel base as required and position the indicator tip slightly above the connecting rod cap. Lock the swivel base in position by rotating the locking lever (1). Do not allow the tip of the indicator to contact the connecting rod at this time.
19. The tip of the indicator should be positioned above and NOT in contact with the cap end of the connecting rod.
20. Rotate the fine adjustment knobs on the dial indicator end of the swivel base to position the tip of the indicator in contact with the connecting rod.
21. Lightly actuate the handle of the pivot arm assembly, multiple times in both directions, to ensure the oil film is removed from the journal.
22. Load the handle in the forward position and zero the dial indicator. Load the handle multiple times in both directions and record the reading. Important: During this procedure, card stock may enter the crankshaft journal oil galleries. Be sure to remove all card stock from the bearing journal and oil galleries prior to reassembly.
23. Remove the bearing cap bolts, cap, and paper stock.
24. Replace bearing halves as required to obtain the proper bearing clearances.
25. Install the bearings, cap, and bolts. Refer to «Fastener Tightening Specifications»(ref-176270-S00946143732005050300000) .

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1. Install the crankshaft bearings into the engine block.
2. Install the crankshaft.
3. Install the gaging plastic the full width of the journal.
4. Install the crankshaft bearings into the crankshaft bearing caps.
5. Install the crankshaft bearing caps in the original positions and with the arrow on the crankshaft bearing caps in the direction of the front of the engine block.
6. Install the crankshaft bearing cap bolts. Tighten the crankshaft bearing caps to 105 N.m (77 ft lbs).
7. Remove the crankshaft bearing cap bolts.
8. Remove the crankshaft bearing caps. The gaging plastic may adhere to either the crankshaft bearing journal or the crankshaft bearing surface.
9. Without removing the gaging plastic, measure the compressed width at the widest point using the graduated scale on the edge of the gaging plastic envelope. If the flattened gaging plastic tapers toward the middle or the ends, there may be a difference in clearance indicating taper, low spot or other irregularity of the crankshaft bearing or the crankshaft bearing journal.
10. Remove the flattened gaging plastic.
11. Measure the remaining crankshaft bearing journals.

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1. Insert a feeler gage between the connecting rod caps and measure the connecting rod side clearance. The proper connecting rod side clearance specification is 0.15-0.44 mm (0.006-0.017 in).
2. Connecting rod side clearances may also be measured with a dial indicator set.

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1. Clean the crankshaft balancer in cleaning solvent.
2. Dry the crankshaft balancer with compressed air.
3. Inspect the crankshaft balancer for the following: Loose or improperly installed crankshaft balancer front groove pin (1). A properly installed front groove pin should be installed until flush or below flush with the face of the crankshaft balancer. Important: A crankshaft front oil sealing surface with excessive scoring, grooves, rust, or other damage must be replaced. Worn, grooved, or damaged crankshaft front oil sealing surface (2). Minor imperfections on the crankshaft balancer crankshaft front oil seal surface may be removed with a polishing compound or fine grade emery cloth. Worn, chunking, or deteriorated rubber (3) between the hub and the outer ring Worn or damaged keyway (4) Worn or damaged bolt hole threads (5)

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1. Clean the engine flywheel (1 or 2) in cleaning solvent.
2. Dry the engine flywheel with compressed air. Important: Do not attempt to repair the welded areas, if present, that retain the ring gear to the engine flywheel plate. Always install a NEW engine flywheel.
3. Inspect the engine flywheel, automatic transmission, if equipped, for the following: Stress cracks around the engine flywheel-to-torque converter bolt hole locations (1) Missing balance weights Stress cracks around the engine flywheel-to-crankshaft bolt hole locations (2 or 3) Welded areas that retain the ring gear onto the engine flywheel for cracking (4), if present Damaged ring gear teeth (5)
4. Inspect the engine flywheel, manual transmission, if equipped, for loose or improperly installed flywheel weights, if applicable. A properly installed flywheel weight should be installed until flush or below flush with the face of the engine flywheel.
5. Inspect the engine flywheel, manual transmission, if equipped, for the following: Pitted friction 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 the ring gear should be positioned completely flat against the flange of the engine flywheel.

Valve Guide Reaming/Valve & Seat Grinding

Tools Required

J 5830-02 Valve Guide Reamer Set

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1. Measure the valve stem-to-guide clearance. Refer to «Cylinder Head Cleaning & Inspection»(ref-176270-S26446188622005050300000) .
2. Improper valve stem (1) to valve guide (2) clearance may cause excessive oil consumption. Important: Exhaust valves with excessive valve stem-to-guide clearance must be replaced with the available service valve that has an 0.774 mm (0.0305 in) oversize valve stem. The intake valves are NOT available with oversize valve stems. Replace the cylinder head if after using a NEW intake valve in order to measure the valve stem-to-guide clearance, the valve stem-to-guide clearance is not within specifications.
3. Use the J 5830-3 in order to ream the exhaust valve guide in order to achieve the correct valve stem-to-guide clearance.
4. Always recondition the exhaust valve seat after reaming the exhaust valve guide bores and installing new exhaust valves.
5. Inspect the valves for the following: Burnt or damaged areas (1) Undersized margin (2) Bent stem (3) Scoring or other damage to the stem (4) Worn key groove (5) Worn stem tip (6)
6. Inspect the valve contact surface for the following: Undersized margin (1) Pitted surface (2) Burnt or eroded areas (3) Acceptable edge margin (4). Valves with excessive damage must be replaced. Minor imperfections of the valve or valve seat may be repaired.
7. Reconditioning of the valves and valve seats: The valves must seat perfectly for the engine to deliver optimum power and performance. Cooling the valve heads is another important factor. Good contact between each valve and valve seat in the cylinder head is necessary to insure that the heat in the valve head is properly carried away.
8. Regardless of what type of equipment is used, it is essential that the valve guide bores are free from carbon or dirt in order to ensure the proper centering of the pilot in the valve guide. The valve seats should be concentric to within 0.05 mm (0.002 in) total indicator reading.
9. Reface pitted valves on a valve refacing machine in order to ensure the correct relationship between the valve head and the valve stem. Replace the valve if the valve stem is excessively worn or warped. Replace the valve if the edge margin (4) of the valve head is less than 0.79 mm (0.031 in) thick after grinding.
10. Several different types of equipment are available for reconditioning valves and valve seats. Follow the equipment manufacturer's recommendations for equipment use to attain the proper results.

Thread Repair

General purpose thread repair kits are available commercially.

Important: Refer to the thread repair kit manufacturer's instructions regarding the size of the drill and which tap to use.

Always avoid any buildup of chips. Back out the tap every few turns and remove the chips.

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1. Determine the size, the pitch, and the depth of the damaged thread.
2. Adjust the stop collars on the cutting tool as needed. Tap the stop collars to the required depth.
3. Drill out the damaged thread.
4. Remove the chips.
5. Apply clean engine oil to the top thread.
6. Use the tap in order to cut new thread.
7. Clean the thread.
8. Screw the thread insert onto the mandrel of the thread insert installer. Engage the tang of the thread insert onto the end of the mandrel. Important: The thread insert should be flush to 1 turn below the surface.
9. Lubricate the thread insert with clean engine oil - except when installing in aluminum - and install the thread insert.
10. If the tang of the thread insert does not break off when backing out the thread insert installer, break off the tang using a drift punch.

Piston Selection

Important: Measurements of all components should be taken with the components at normal room temperature.

For proper piston fit, the engine block cylinder bores should not have excessive wear or taper.

A used piston and piston pin set may be reinstalled if, after cleaning and inspection, the piston and piston pin are within specifications.

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1. Use the J 8087 in order to measure the cylinder bore diameter. Measure at a point 64 mm (2.5 in) from the top of the cylinder bore and 90 degrees to the crankshaft centerline.
2. Measure the J 8087 with a micrometer and record the reading.
3. With a micrometer or caliper at a right angle to the piston pin bore, measure the piston 11 mm (0.433 in) from the bottom of the skirt.
4. Subtract the piston diameter from the cylinder bore diameter in order to determine piston-to-bore clearance. Refer to «Engine Mechanical Specifications»(ref-176270-S25975192972005050300000) .
5. If the proper clearance cannot be obtained, then select another piston and measure the clearances. If the proper fit cannot be obtained, the cylinder bore may require honing or boring.
6. When the piston-to-cylinder bore clearance is within specifications, permanently mark the top of the piston for installation into the proper cylinder.

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1. Apply clean engine oil to the following components: The piston The piston rings The cylinder bore The bearing surfaces
2. Install the J 5239 onto the connecting rod bolts.
3. Install the J 8037 onto the piston and compress the piston rings. Important: The mark on the top of the piston must face the front of the engine block. When assembled, the flanges on the connecting rod and connecting rod cap should face to the front of the engine block on the left bank, and to the rear of the engine block on the right bank.
4. Install the piston and connecting rod assembly, and the J 8037 into the proper cylinder bore.
5. Use the J 8037 and the J 5239 and lightly tap the top of the piston with a wooden hammer handle. 5.1. Hold the J 8037 firmly against the engine block until all of the piston rings have entered the cylinder bore. 5.2. Use the J 5239 in order to guide the connecting rod onto the crankshaft journal.
6. Remove the J 5239.
7. Install the connecting rod caps, bearings, and nuts. 7.1. Tighten the nuts evenly on the first pass to 27 N.m (20 ft lbs). 7.2. Use the J 36660-A in order to tighten the nuts on the final pass an additional 70 degrees.
8. After the piston and connecting rod assemblies have been installed, lightly tap each connecting rod assembly, parallel to the crankpin, in order to ensure that the connecting rods have side clearance.
9. Use a feeler gage or a dial indicator to measure the connecting rod side clearance between the connecting rod caps. The connecting rod side clearance should be 0.15-0.44 mm (0.006-0.017 in).

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1. Apply clean engine oil GM P/N 12345610 (Canadian P/N 993193) or equivalent, or engine oil supplement GM P/N 1052367 (Canadian P/N 992367) or equivalent, to the following components: The engine camshaft lobes The camshaft bearing journals The camshaft bearings The distributor drive gear
2. Install three 5/16-18 x 4.0 inch bolts into the engine camshaft front bolt holes. NOTE: All camshaft journals are the same diameter, so care must be used in removing or installing the camshaft to avoid damage to the camshaft bearings.
3. Use the bolts as a handle in order to install the engine camshaft.
4. Remove the 3 bolts from the front of the engine camshaft.
5. If reusing the fasteners, apply threadlock GM P/N 12345382 (Canadian P/N 10953489) or equivalent, to the threads of the camshaft retainer bolts.
6. Install the camshaft retainer and bolts. Tighten the camshaft retainer bolts to 12 N.m (106 in lbs).

Balance Shaft

The cast iron balance shaft is mounted in the crankcase above and in-line with the camshaft. A camshaft gear drives the gear attached to the balance shaft. The front end of the balance shaft is supported by a ball-type bearing. The rear end of the balance shaft uses a sleeve-type bearing.

Camshaft

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

Crankshaft

The cast nodular iron crankshaft is supported by four crankshaft bearings. The number four crankshaft bearing at the rear of the engine is the end thrust bearing. The crankshaft bearings are retained by bearing caps that are machined with the engine block for proper alignment and clearances. The crankshaft position sensor reluctor ring has three lugs used for crankshaft timing and is constructed of powdered metal. The crankshaft position sensor reluctor ring has a slight interference fit onto the crankshaft and an internal keyway for correct positioning.

Cylinder Heads

The cast iron cylinder heads have one intake and one exhaust valve for each cylinder. A spark plug is located between the valves in the side of the cylinder head. The valve guides and seats are integral to the cylinder head. The 4.3L heavy duty applications have pressed in exhaust valve seats. The valve rocker arms are positioned on the valve rocker arm supports and retained by a bolt.

Engine Block

The cast iron engine block has six cylinders arranged in a V shape with three cylinders in each bank. Starting at the front side of the engine block, the cylinders in the left bank are numbered 1-3-5 and cylinders in the right bank are numbered 2-4-6 (when viewed from the rear). The firing order of the cylinders is 1-6-5-4-3-2. The cylinders are encircled by coolant jackets.

Exhaust Manifolds

The cast iron exhaust manifolds direct exhaust gases from the combustion chambers to the exhaust system. The left side exhaust manifold has a port for the EGR valve inlet pipe.

Intake Manifold

The intake manifold is a two-piece design. The upper portion is made from a composite material and the lower portion is cast aluminum. The throttle body attaches to the upper manifold. The lower manifold has an exhaust gas recirculation (EGR) port cast into the manifold for mixture. The (EGR) valve bolts into the lower intake manifold. The Central Sequential Multiport Fuel Injection system uses multiple fuel injectors to meter and distribute fuel to each engine cylinder. The Central (SFI) is retained by a bracket bolted to the lower intake manifold. The fuel meter body also houses the pressure regulator. Metal inlet and outlet fuel lines and nylon delivery tubes connect to the Central (SFI) unit. The delivery tubes independently distribute fuel to each cylinder through nozzles located at the port entrance of each manifold runner where the fuel is atomized.

Valve Train

Motion is transmitted from the camshaft through the hydraulic roller valve lifters and the tubular valve pushrods to the roller type valve rocker arms. The roller type valve rocker arm pivots on a needle type bearing in order to open the valve. The valve rocker arms for each bank of cylinders are mounted to a one piece valve rocker arm support. Each valve rocker arm is retained on the valve rocker arm support and the cylinder head by a bolt. The hydraulic valve lifters keep all the parts of the valve train in constant contact. Each hydraulic valve lifter acts as an automatic adjuster and maintains zero lash in the valve train. This eliminates the need for periodic valve adjustment.

New Product Information

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

Changes may include one or more of the following items

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

Component Comparison

1. Revised the water pump seal
2. Revised the engine coolant thermostat
3. New roller pivot type valve rocker arm assemblies using a one piece valve rocker arm support to replace the ball pivot type valve rocker arm system
4. Cylinder heads revised using dry holes for the valve rocker arm bolts

New Sealants and/or Adhesives

No new sealants or adhesive have been added.

Cleanliness & 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, the components should be marked, organized or retained in a specific order for re-assembly.
4. At the time of installation, the 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. The surfaces should be protected to avoid component damage.
6. Apply a liberal amount of clean engine oil to friction areas during assembly.
7. Proper lubrication will protect and lubricate friction areas during initial operation.

Gasket Reuse & 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.

1. 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.

Sealant Types

Important: The correct sealant and amount of sealant must be used in the proper location to prevent oil leaks, coolant leaks, or the loosening of the fasteners. DO NOT interchange the sealants. Use only the sealant, or equivalent, as specified in the service procedure.

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

1. Aerobic sealant Room Temperature Vulcanizing (RTV)
2. Anaerobic sealant, which include the following: Gasket eliminator Pipe Threadlock

Aerobic Type Room Temperature Vulcanizing (RTV) Sealant

Aerobic type Room Temperature Vulcanizing (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

1. The exhaust manifold
2. The head gasket
3. Any other surfaces where a different type of sealant is specified in the service procedure

1. Always follow all the safety recommendations and the directions that are on the RTV sealant container.
2. Use a plastic or wood scraper in order to remove all the RTV sealant from the components.

Note. Do not allow the RTV sealant to enter any blind threaded hole. RTV sealant that is allowed to enter a blind threaded hole can cause hydraulic lock of the fastener when the fastener is tightened. Hydraulic lock of a fastener can lead to damage to the fastener and/or the components. Hydraulic lock of a fastener can also prevent the proper clamping loads to be obtained when the fastener is tightened. Improper clamping loads can prevent proper sealing of the components allowing leakage to occur. Preventing proper fastener tightening can allow the components to loosen or separate leading to extensive engine damage.

1. The surfaces to be sealed must be clean and dry.
2. Use a RTV sealant bead size as specified in the service procedure.
3. Apply the RTV sealant bead to the inside of any bolt holes areas.

Important: Do not wait for the RTV sealant to skin over.

1. Assemble the components while the RTV sealant is still wet to the touch, within 3 minutes.

Important: Do not overtighten the fasteners.

1. Tighten the fasteners in sequence, if specified, and to the proper torque specifications.

Anaerobic Type Gasket Eliminator Sealant

Anaerobic type gasket eliminator sealant cures in the absence of air. This type of sealant is used where 2 rigid parts, such as castings, are assembled together. When 2 rigid parts are disassembled and no sealant or gasket is readily noticeable, then 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 the safety recommendations and directions that are on the gasket eliminator sealant container.
2. Apply a continuous bead of gasket eliminator sealant to one flange. The surfaces to be sealed must be clean and dry.

Note. Do not allow the sealant to enter a blind hole. The sealant may prevent the fastener from achieving proper clamp load, cause component damage when the fastener is tightened, or lead to component failure.

Important

1. Gasket eliminator sealed joint fasteners that are partially torqued and the gasket eliminator sealant allowed to cure more than five minutes, may result in incorrect shimming and sealing of the joint.
2. Do not overtighten the fasteners. Apply the gasket eliminator sealant evenly to get a uniform thickness of the gasket eliminator sealant on the sealing surface. Tighten the fasteners in sequence, if specified, and to the proper torque specifications. After properly tightening the fasteners, remove the excess gasket eliminator sealant from the outside of the joint.

Anaerobic Type 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.

Important

1. Fasteners that are partially torqued and then the threadlock sealant allowed to cure more than five minutes, may result in incorrect clamp load of assembled components.
2. Do not overtighten the fasteners.
3. Tighten the fasteners in sequence, if specified, and to the proper torque specifications.

Anaerobic Type 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 parts 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

1. The exhaust manifold
2. The head gasket
3. Surfaces where a different sealant is specified

1. Always follow all the safety recommendations and the directions that are on the pipe sealant container.
2. The surfaces to be sealed must be clean and dry.
3. Use a pipe sealant bead of the size or quantity as specified in the service procedure.

Note. Do not allow the sealant to enter a blind hole. The sealant may prevent the fastener from achieving proper clamp load, cause component damage when the fastener is tightened, or lead to component failure.

1. Apply the pipe sealant bead to the inside of any bolt hole areas.
2. Apply a continuous bead of pipe sealant to 1 sealing surface.

Important: Do not overtighten the fasteners.

1. Tighten the fasteners in sequence, if specified, and to the proper torque specifications.

Separating Parts

Important: Many internal engine components will develop specific wear patterns on their friction surfaces.

When disassembling the engine, internal components MUST be separated, marked and organized in a way to ensure reinstallation to original location and position.

Mark or identify the following components

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

Tools & Equipment

Special tools are listed and illustrated throughout this section with a complete listing at the end of the section. The tools (or the equivalents) are specially designed to quickly and safely accomplish the operations for which the tools are intended. The use of special tools will 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.

To properly service the engine assembly, the following items should be readily available

1. Approved eye protection and safety gloves
2. A clean, well-lit, work area
3. A suitable parts cleaning tank
4. A compressed air supply
5. Trays or storage containers to keep parts and fasteners organized
6. An adequate set of hand tools
7. Approved engine repair stand
8. An approved engine lifting device that will adequately support the weight of the components

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