Engine Mechanical - 4.3L: Removal & Installation Chevrolet Silverado Classic 1500 HD

Removal Procedure

1. Install a 3/8 inch drive breaker bar to the drive belt tensioner arm.
2. Rotate the drive belt tensioner (2) counterclockwise in order to relieve tension on the belt.
3. If equipped without air conditioning (A/C), remove the belt (1) from the pulleys and the drive belt tensioner.
4. If equipped with A/C, remove the belt (1) from the pulleys and the drive belt tensioner.
5. Slowly release the tension on the drive belt tensioner (2).
6. Remove the breaker bar from the drive belt tensioner.
7. Clean and inspect the belt surfaces of all the pulleys.

Installation Procedure

1. Route the belt (1) around all the pulleys except the flat idler pulley.
2. Install a 3/8 inch drive breaker bar to the drive belt tensioner arm.
3. Rotate the belt tensioner (2) counterclockwise in order to relieve the tension on the tensioner.
4. If equipped with A/C, install the belt under the flat idler pulley.
5. If equipped without A/C, install the belt (1) to the pulleys and the drive belt tensioner.
6. Slowly release the tension on the belt tensioner (2).
7. Remove the breaker bar from the drive belt tensioner.
8. Inspect the drive belt for proper installation and alignment.

1. Remove the drive belt. Refer to «Drive Belt Replacement»(ref-277938-S02095851762008012100000) .
2. Remove the belt tensioner bolt.
3. Remove the belt tensioner. Ensure that there is a locating pin (1) on the tensioner.

1. Install the belt tensioner. Position the locating pin (1) on the tensioner into the hole in the generator bracket.
2. Install the belt tensioner bolt. Tighten: Tighten the bolt to 50 N.m (37 lb ft).
3. Install the drive belt. Refer to «Drive Belt Replacement»(ref-277938-S02095851762008012100000) .

1. Loosen the idler pulley bolt.
2. Remove the drive belt. Refer to «Drive Belt Replacement»(ref-277938-S02095851762008012100000) .
3. Remove the idler pulley.

1. Install the idler pulley.
2. Install the idler pulley bolt until snug.
3. Install the drive belt. Refer to «Drive Belt Replacement»(ref-277938-S02095851762008012100000) . NOTE: Refer to «Fastener Notice»(ref-277849-S30907907212008012100000) .
4. Tighten the idler pulley bolt. Tighten: Tighten the bolt to 50 N.m (37 lb ft).

1. Loosen the idler pulley bolt.
2. Remove the drive belt. Refer to «Drive Belt Replacement»(ref-277938-S02095851762008012100000) .
3. Remove the idler pulley.

1. Install the idler pulley.
2. Install the idler pulley bolt until snug.
3. Install the drive belt. Refer to «Drive Belt Replacement»(ref-277938-S02095851762008012100000) . NOTE: Refer to «Fastener Notice»(ref-277849-S30907907212008012100000) .
4. Tighten the idler pulley bolt. Tighten: Tighten the bolt to 50 N.m (37 lb ft).

Note. Refer to Engine Mounting Notice .

1. From under the hood, remove the engine mount to engine mount bracket bolts. (right side shown, left side similar).
2. Raise and suitably support the vehicle. Refer to «Lifting and Jacking the Vehicle»(ref-277851-S21776392712008012100000) .
3. Remove the oil pan skid plate bolts and plate.
4. Using an adjustable jack on the square tab at the rear of the engine block, raise the engine.
5. Remove the engine mount bolts. (right side shown, left side similar).
6. Remove the engine mount.
7. If equipped and necessary, remove the engine mount side bracket bolts and bracket. (right side shown, left side similar).
8. Remove the engine mount bracket bolts.
9. Remove the engine mount bracket.

1. Install the engine mount bracket.
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 GM P/N 12345382 (Canadian P/N 10953489) or equivalent to the bolts.
3. Install the engine mount bracket bolts. Tighten: Tighten the engine mount bracket bolts to 75 N.m (55 lb ft).
4. Position the engine mount side bracket to the engine, if removed and equipped. (right side shown, left side similar).
5. Install the engine mount side bracket bolts. Tighten: Tighten the engine mount side bracket bolts to 50 N.m (37 lb ft).
6. Install the engine mount. (right side shown, left side similar).
7. Install the engine mount bolts. Tighten: Tighten the engine mount bolts to 50 N.m (37 lb ft).
8. Lower the engine.
9. Install the oil pan skid plate and bolts. Tighten: Tighten the oil pan skid plate bolts to 20 N.m (15 lb ft).
10. Lower the vehicle.
11. Install the engine mount to engine mount bracket bolts. (right side shown, left side similar). Tighten: Tighten the engine mount to engine mount bracket bolts to 65 N.m (48 lb ft).

Note. Refer to Engine Mounting Notice .

1. From under the hood, remove the engine mount to engine mount bracket bolts. (left side shown, right side similar).
2. Raise and suitably support the vehicle. Refer to «Lifting and Jacking the Vehicle»(ref-277851-S21776392712008012100000) .
3. Remove the oil pan skid plate bolts and plate.
4. Using an adjustable jack on the square tab (left side shown) at the rear of the engine block, raise the engine. In order to access the square tab, remove the starter. (left side shown, right side similar). Refer to «Starter Motor Replacement (4.3L Engine)»(ref-277854-S36909298662008012100000) .
5. Remove the engine mount bolts.
6. Remove the engine mount.
7. If necessary, remove the engine mount side bracket bolts and bracket.
8. Remove the engine mount bracket bolts.
9. Remove the engine mount bracket.

1. Install the engine mount bracket.
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 GM P/N 12345382 (Canadian P/N 10953489) or equivalent to the bolts.
3. Install the engine mount bracket bolts. Tighten: Tighten the engine mount bracket bolts to 75 N.m (55 lb ft).
4. Position the engine mount side bracket to the engine, if removed.
5. Install the engine mount side bracket bolts. Tighten: Tighten the engine mount side bracket bolts to 50 N.m (37 lb ft).
6. Install the engine mount.
7. Install the engine mount bolts. Tighten: Tighten the engine mount bolts to 50 N.m (37 lb ft).
8. Lower the engine.
9. Install the starter. Refer to «Starter Motor Replacement (4.3L Engine)»(ref-277854-S36909298662008012100000) .
10. Install the oil pan skid plate and bolts. Tighten: Tighten the oil pan skid plate bolts to 20 N.m (15 lb ft).
11. Lower the vehicle.
12. 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).

1. Remove the fuel pipes/hoses. Refer to «Fuel Hose/Pipes Replacement - Engine Compartment»(ref-277873-S29478769382008012100000) .
2. Disconnect the cruise control cable from the throttle lever, if equipped.
3. Remove the cruise control cable from the accelerator control cable bracket, if equipped.
4. Remove the accelerator cable from the throttle body lever.
5. Remove the accelerator cable from the accelerator control cable bracket.
6. Disconnect the following electrical connectors: The air conditioning (A/C) compressor clutch (1), if equipped The A/C pressure switch (4), if equipped
7. Remove the engine wiring harness clip (3) from the accelerator control cable bracket.
8. Remove the accelerator control cable bracket nuts.
9. Remove the accelerator control cable bracket with the cables attached, from the throttle body.
10. Reposition and secure the bracket and cables out of the way.
11. Disconnect the following electrical connectors: The throttle position (TP) sensor (1) The idle air control (IAC) motor (2) The control port injector module (3)
12. Remove the engine wiring harness clip bolt (4).
13. Disconnect the following electrical connectors: The evaporative emission (EVAP) canister purge solenoid valve (1) The manifold absolute pressure (MAP) sensor (2)
14. Disconnect the EVAP canister tube (1) from the purge solenoid valve (2).
15. Remove the engine wiring harness bracket nuts.
16. Remove the engine wiring harness bracket.
17. Remove the engine wiring harness ground nut and ground wire (4) from the rear of the right cylinder head.
18. Remove the engine wiring harness rear bracket nut at the EVAP canister purge solenoid valve.
19. Remove the stud holding the engine wiring harness bracket.
20. Reposition the engine wiring harness with the bracket aside.
21. Remove the positive crankcase ventilation (PCV) valve hose from the valve and rocker cover.
22. Disconnect the power brake booster vacuum hose from the vacuum fitting.
23. Remove the accelerator cable bracket nuts.
24. Remove the accelerator cable bracket.
25. Remove the intake manifold-upper studs.
26. Remove the front 2 throttle body studs.
27. Remove the intake manifold-upper.
28. Remove and discard the intake manifold-upper gasket.
29. Remove and discard the O-ring seal from the fuel meter body.
30. If required, remove the power brake booster vacuum fitting.
31. Remove and discard the O-ring seal.
32. If required, remove the PCV valve cover.
33. Remove and discard the O-ring seal.
34. If required, remove the rear throttle body stud.
35. Remove the throttle body.
36. Remove and discard the throttle body gasket.
37. If required, remove the MAP sensor.
38. Remove and discard the MAP sensor seal.
39. If required, remove the EVAP canister purge solenoid valve studs.
40. Remove the purge solenoid valve.
41. Clean and inspect the intake manifold-upper, if necessary. Refer to «Intake Manifold Cleaning and Inspection»(ref-277938-S33070168392008012100000) .

1. If required, install the purge solenoid valve.
2. Install the EVAP canister purge solenoid valve studs. If reusing the old studs, apply threadlock to the threads. Refer to «Sealers, Adhesives, and Lubricants»(ref-277938-S13821020292008012100000) for the correct part number. Tighten: Tighten the studs to 10 N.m (89 lb in).
3. If required, install a NEW MAP sensor seal. Apply a small drop of clean engine oil to the seal.
4. Install the MAP sensor.
5. If required, install a NEW throttle body gasket.
6. Install the throttle body.
7. Install the rear throttle body stud. If reusing the old stud, apply threadlock to the threads. Refer to «Sealers, Adhesives, and Lubricants»(ref-277938-S13821020292008012100000) for the correct part number. Tighten: Tighten the stud to 9 N.m (80 lb in).
8. If required, install a NEW O-ring seal to the PCV cover. Apply clean engine oil to the seal.
9. Install the PCV valve cover.
10. If required, install a NEW O-ring seal. Apply clean engine oil to the seal.
11. Install the power brake booster vacuum fitting.
12. Install a NEW O-ring seal to the fuel meter body.
13. Install a NEW upper intake manifold gasket.
14. Install the intake manifold - upper.
15. If reusing the old throttle body/intake manifold studs, apply threadlock to the threads. Refer to «Sealers, Adhesives, and Lubricants»(ref-277938-S13821020292008012100000) for the correct part number.
16. Install the front two throttle body studs.
17. Install the intake manifold - upper studs. Tighten: Tighten the studs to 9 N.m (80 lb in).
18. Install the accelerator cable bracket.
19. Install the accelerator cable bracket nuts. Tighten: Tighten the nuts to 12 N.m (106 lb in).
20. Connect the power brake booster vacuum hose to the vacuum fitting.
21. Install the PCV valve hose to the valve cover and rocker cover.
22. Position the engine wiring harness and bracket.
23. Install the engine wiring harness bracket stud. Tighten: Tighten the stud to 25 N.m (18 lb ft).
24. Install the engine wiring harness rear bracket nut at the EVAP canister purge solenoid valve. Tighten: Tighten the nut to 9 N.m (80 lb in).
25. Install the engine wiring harness ground nut and ground wire (4) to the rear of the right cylinder head. Tighten: Tighten the nut to 16 N.m (12 lb ft).
26. Install the engine wiring harness bracket.
27. Install the engine wiring harness bracket nuts. Tighten: Tighten the nuts to 12 N.m (106 lb in).
28. Connect the EVAP canister tube (1) to the purge solenoid valve (2).
29. Connect the following electrical connectors: The EVAP canister purge solenoid valve (1) The MAP sensor (2)
30. Connect the following electrical connectors: The TP sensor (1) The IAC motor (2) The control port injector module (3)
31. Install the engine wiring harness clip bolt (4). Tighten: Tighten the bolt to 9 N.m (80 lb in).
32. Position the bracket and cables.
33. Install the accelerator control cable bracket with the cables attached, to the throttle body.
34. Install the accelerator control cable bracket nuts. Tighten: Tighten the nuts to 9 N.m (80 lb in).
35. Connect the following electrical connectors: The A/C compressor clutch (1), if equipped The A/C pressure switch (4), if equipped
36. Install the engine wiring harness clip (3) to the accelerator control cable bracket.
37. Install the accelerator cable to the accelerator control cable bracket.
38. Install the accelerator cable to the throttle body lever.
39. Install the cruise control cable to the accelerator control cable bracket, if equipped.
40. Connect the cruise control cable to the throttle lever, if equipped.
41. Install the fuel pipes/hoses. Refer to «Fuel Hose/Pipes Replacement - Engine Compartment»(ref-277873-S29478769382008012100000) .

1. Drain the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(ref-277850-S07555853772008012100000) or «Draining and Filling Cooling System (w/RPO HP2)»(ref-277850-S31192445052008012100000) or «Draining and Filling Cooling System (Vac-N-Fill)»(ref-277850-S00482587952008012100000) .
2. Remove the fuel pipes/hoses. Refer to «Fuel Hose/Pipes Replacement - Engine Compartment»(ref-277873-S29478769382008012100000) .
3. Remove the distributor. Refer to «Distributor Replacement»(ref-277873-S23388997282008012100000) .
4. Disconnect the evaporative emission (EVAP) canister harness from the purge solenoid valve.
5. Remove the heater hose clamp (1).
6. Open the heater outlet hose clamp and remove the hose from the intake manifold.
7. Open the heater inlet hose clamp and remove the hose from the water pump.
8. Reposition the heater inlet and outlet hoses.
9. Disconnect the cruise control cable from the throttle body lever, if equipped.
10. Remove the cruise control cable from the accelerator control cable bracket, if equipped.
11. Remove the accelerator cable from the throttle body lever.
12. Remove the accelerator cable from the accelerator control cable bracket.
13. Disconnect the following electrical connectors: The air conditioning (A/C) compressor clutch (1), if equipped The A/C pressure switch (4), if equipped
14. Remove the engine wiring harness clip (3) from the accelerator control cable bracket.
15. Remove the accelerator control cable bracket nuts.
16. Remove the accelerator control cable bracket with the cables attached, from the throttle body.
17. Reposition and secure the bracket and cables out of the way.
18. Disconnect the following electrical connectors: The throttle position (TP) sensor (1) The idle air control (IAC) motor (2) The control port injector module (3)
19. Remove the engine wiring harness clip bolt (4).
20. Disconnect the following electrical connectors: The EVAP canister purge solenoid valve (1) The manifold absolute pressure (MAP) sensor (2)
21. Remove the engine wiring harness bracket nuts.
22. Remove the engine wiring harness bracket.
23. Remove the engine wiring harness ground nut and ground wire (4) from the rear of the right cylinder head.
24. Remove the engine wiring harness rear bracket nut at the EVAP canister purge solenoid valve.
25. Remove the stud holding the engine wiring harness bracket.
26. Reposition the engine wiring harness with the bracket aside.
27. Remove the positive crankcase ventilation (PCV) valve hose from the valve cover and rocker cover.
28. Disconnect the power brake booster vacuum hose from the vacuum fitting.
29. Reposition the radiator inlet hose clamps.
30. Remove the radiator inlet hose from the thermostat housing.
31. Reposition the water pump inlet hose clamps.
32. Remove the water pump inlet hose.
33. In order to remove the front intake manifold bolt, perform the following: Remove the drive belt. Refer to «Drive Belt Replacement»(ref-277938-S02095851762008012100000) . Loosen the power steering (P/S) pump rear bracket nut. Remove the P/S pump rear bracket front nut. Remove the bolts and the nut for the P/S pump bracket. Leave the A/C compressor, if equipped, and the P/S pump on the bracket. Slide the P/S pump bracket forward to access the front intake manifold bolt.
34. Remove the intake manifold-lower bolts.
35. Remove the intake manifold.
36. Remove and discard the intake manifold gaskets.
37. Clean and inspect the intake manifold-lower, if necessary. Refer to «Intake Manifold Cleaning and Inspection»(ref-277938-S33070168392008012100000) .

Note. Apply the proper amount of the sealant when assembling this component. Excessive use of the sealant can prohibit the component from sealing properly. A component that is not sealed properly can leak leading to extensive engine damage.

1. Apply a 4.0 mm (0.157 in) patch of adhesive to the cylinder head side of the intake manifold gasket at each end. Refer to «Sealers, Adhesives, and Lubricants»(ref-277938-S13821020292008012100000) for the correct part number.
2. Install the intake manifold gasket onto the cylinder head. Use the gasket locating pins in order to properly seat the gasket.
3. Apply a 5 mm (0.197 in) bead of adhesive to the front top of the engine block. Refer to «Sealers, Adhesives, and Lubricants»(ref-277938-S13821020292008012100000) for the correct part number.
4. Extend the adhesive bead 13 mm (0.50 in) up onto each intake manifold gasket.
5. Apply a 5 mm (0.197 in) bead of adhesive to the rear top of the engine block. Refer to «Sealers, Adhesives, and Lubricants»(ref-277938-S13821020292008012100000) for the correct part number.
6. Extend the adhesive bead 13 mm (0.50 in) up onto each intake manifold gasket.
7. Install the intake manifold.
8. If reusing the old fasteners, apply threadlock to the threads of the intake manifold - lower bolts. Refer to «Sealers, Adhesives, and Lubricants»(ref-277938-S13821020292008012100000) for the correct part number.
9. Install the intake manifold - lower bolts.
10. Tighten the intake manifold-lower bolts in the sequence shown. Tighten: Tighten the bolts a first pass to 3 N.m (27 lb in). Tighten the bolts a second pass to 12 N.m (106 lb in). Tighten the bolts a final pass to 15 N.m (11 lb ft).
11. Slide the P/S pump bracket rearward.
12. Install the bolts and the nut for the P/S pump bracket.
13. Install the P/S pump rear bracket front nut.
14. Tighten the P/S pump rear bracket nut. Tighten: Tighten the bolts and nuts to 41 N.m (30 lb ft).
15. Install the drive belt. Refer to «Drive Belt Replacement»(ref-277938-S02095851762008012100000) .
16. Install the water pump inlet hose.
17. Position the water pump inlet hose clamps.
18. Install the radiator inlet hose to the thermostat housing.
19. Position the radiator inlet hose clamps.
20. Connect the power brake booster vacuum hose to the vacuum fitting.
21. Install the PCV valve hose to the valve cover and rocker cover.
22. Position the engine wiring harness and bracket.
23. Install the engine wiring harness bracket stud. Tighten: Tighten the stud to 25 N.m (18 lb ft).
24. Install the engine wiring harness rear bracket nut at the EVAP canister purge solenoid valve. Tighten: Tighten the nut to 9 N.m (80 lb in).
25. Install the engine wiring harness ground nut and ground wire (4) to the rear of the right cylinder head. Tighten: Tighten the nut to 16 N.m (12 lb ft).
26. Install the engine wiring harness bracket.
27. Install the engine wiring harness bracket nuts. Tighten: Tighten the nuts to 12 N.m (106 lb in).
28. Connect the EVAP canister harness to the purge solenoid valve.
29. Connect the following electrical connectors: The EVAP canister purge solenoid valve (1) The MAP sensor (2)
30. Connect the following electrical connectors: The TP sensor (1) The IAC motor (2) The control port injector module (3)
31. Install the engine wiring harness clip bolt (4). Tighten: Tighten the bolt to 9 N.m (80 lb in).
32. Position the bracket and cables.
33. Install the accelerator control cable bracket with the cables attached, to the throttle body.
34. Install the accelerator control cable bracket nuts. Tighten: Tighten the nuts to 9 N.m (80 lb in).
35. Connect the following electrical connectors: The A/C compressor clutch (1), if equipped The A/C pressure switch (4), if equipped
36. Install the engine wiring harness clip (3) to the accelerator control cable bracket.
37. Install the accelerator cable to the accelerator control cable bracket.
38. Install the accelerator cable to the throttle body lever.
39. Install the cruise control cable to the accelerator control cable bracket, if equipped.
40. Connect the cruise control cable to the throttle lever, if equipped.
41. Position the heater inlet and outlet hoses.
42. Open the heater inlet hose clamp and install the hose to the water pump.
43. Open the heater out let hose clamp and install the hose to the intake manifold.
44. Install the heater hose clamp (1).
45. Install the fuel pipes/hoses. Refer to «Fuel Hose/Pipes Replacement - Engine Compartment»(ref-277873-S29478769382008012100000) .
46. Install the distributor. Refer to «Distributor Replacement»(ref-277873-S23388997282008012100000) .
47. Fill the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(ref-277850-S07555853772008012100000) or «Draining and Filling Cooling System (w/RPO HP2)»(ref-277850-S31192445052008012100000) or «Draining and Filling Cooling System (Vac-N-Fill)»(ref-277850-S00482587952008012100000) .

1. Remove the engine wiring harness bracket nuts.
2. Remove the engine wiring harness bracket.
3. Remove the engine wiring harness clip bolt (4).
4. Disconnect the engine coolant temperature (ECT) sensor electrical connector (5).
5. Reposition the engine wiring harness and bracket.
6. Disconnect the power brake booster vacuum hose from the vacuum fitting.
7. Remove the positive crankcase ventilation (PCV) valve hose from the valve cover and rocker cover.
8. Remove the rocker arm cover bolts.
9. Remove and discard the rocker arm cover bolt grommets, if necessary.
10. Remove the rocker arm cover.
11. Remove and discard the rocker arm cover gasket.
12. Clean and inspect the rocker arm cover, if necessary. Refer to «Valve Rocker Arm Cover Cleaning and Inspection»(ref-277938-S04106848842008012100000) .

1. Install a NEW rocker arm cover gasket to the cover.
2. Install NEW rocker arm cover bolt grommets to the cover, if necessary.
3. Install the rocker arm cover.
4. Install the rocker arm cover bolts. Tighten: Tighten the bolts to 12 N.m (106 lb in).
5. Install the PCV valve hose to the valve cover and rocker cover.
6. Connect the power brake booster vacuum hose to the vacuum fitting.
7. Position the engine wiring harness and bracket.
8. Connect the ECT sensor electrical connector (5).
9. Install the engine wiring harness clip bolt (4). Tighten: Tighten the bolt to 9 N.m (80 lb in).
10. Install the engine wiring harness bracket.
11. Install the engine wiring harness bracket nuts. Tighten: Tighten the nuts to 12 N.m (106 lb in).

1. Loosen the air cleaner outlet duct clamp at the mass airflow (MAF)/intake air temperature (IAT) sensor.
2. Remove the positive crankcase ventilation (PCV) hose.
3. Remove the air cleaner adapter nut.
4. In order to remove the air cleaner outlet duct, pivot the duct upward until the hinge clip releases from the lip on the throttle body.
5. Remove the heater outlet hose from the clip.
6. Move and secure the heater hoses out of the way.
7. Disconnect the following electrical connectors: The ignition coil (1) The ignition coil drive (2) The generator (3)
8. Disconnect the engine wiring harness clips.
9. Reposition the engine wiring harness.
10. Remove the rocker arm cover bolts.
11. Remove and discard the rocker arm cover bolt grommets, if necessary.
12. Remove the rocker arm cover.
13. Remove and discard the rocker arm cover gasket.
14. Clean and inspect the rocker arm cover, if necessary. Refer to «Valve Rocker Arm Cover Cleaning and Inspection»(ref-277938-S04106848842008012100000) .

1. Install a NEW rocker arm cover gasket.
2. Install NEW rocker arm cover bolt grommets, if necessary.
3. Install the rocker arm cover.
4. Install the rocker arm cover bolts. Tighten: Tighten the bolts to 12 N.m (106 lb in).
5. Position the engine wiring harness.
6. Connect the engine wiring harness clips.
7. Connect the following electrical connectors: The ignition coil (1) The ignition coil drive (2) The generator (3)
8. Position the heater hoses.
9. Install the heater outlet to the hose clip.
10. Align the hinge clip with the lip on the throttle body. In order to install the air cleaner outlet duct, pivot the air cleaner outlet duct downward until the mounting stud is through the hole.
11. Install the air cleaner adapter nut.
12. Install the PCV hose.
13. Tighten the air cleaner outlet duct clamp at the MAF/IAT sensor. Tighten: Tighten the clamp to 4 N.m (35 lb in).

1. Remove the rocker arm cover. Refer to «Valve Rocker Arm Cover Replacement - Left Side»(ref-277938-S20911449062008012100000) or «Valve Rocker Arm Cover Replacement - Right Side»(ref-277938-S21491217102008012100000) .
2. Remove the rocker arms.
3. Remove the rocker arm supports.
4. Remove the pushrods.
5. Clean and inspect the rocker arms and/or pushrods, if necessary. Refer to «Valve Rocker Arm and Push Rods Cleaning and Inspection»(ref-277938-S16696352532008012100000) .

1. Install the pushrods.
2. Install the rocker arm supports.
3. Apply lubricant to the following rocker arm contact surfaces: Pushrod socket (1) Roller pivot (2) Valve stem tip (3) Refer to «Sealers, Adhesives, and Lubricants»(ref-277938-S13821020292008012100000) for the correct part number.
4. Install the rocker arms as follows: Finger start the bolt at location (1) Finger start the bolt at location (2) Finger start the bolt at location (3) Finger start the remaining rocker arm bolts
5. Rotate the crankshaft balancer to position the crankshaft balancer alignment mark (1) 57-63 degrees clockwise or counterclockwise from the engine front cover alignment tab (2).
6. Tighten the rocker arm bolts. Tighten: Tighten bolts to 30 N.m (22 lb ft).
7. Install the rocker arm cover. Refer to «Valve Rocker Arm Cover Replacement - Left Side»(ref-277938-S20911449062008012100000) or «Valve Rocker Arm Cover Replacement - Right Side»(ref-277938-S21491217102008012100000) .

Valve Stem Oil Seal and Valve Spring Replacement

Tools Required

1. J 22794 Spark Plug Port Adapter. See «Special Tools»(ref-277938-S12463979202008012100000) .
2. J 38606 Valve Spring Compressor. See «Special Tools»(ref-277938-S12463979202008012100000) .
3. J 5892-D Valve Spring Compressor. See «Special Tools»(ref-277938-S12463979202008012100000) .
4. J 42073 Valve Stem Oil Seal Installer. See «Special Tools»(ref-277938-S12463979202008012100000) .

1. Remove the required valve rocker arms. Refer to «Valve Rocker Arm and Push Rod Replacement»(ref-277938-S18489440062008012100000) .
2. Remove the required spark plugs. Refer to «Spark Plug Replacement»(ref-277873-S32460422202008012100000) .
3. Install the J 22794 into the spark plug hole. See «Special Tools»(ref-277938-S12463979202008012100000) .
4. Connect a shop air supply hose and apply compressed air in order to hold the valves in place.
5. Install a flat washer onto the removed rocker arm bolt.
6. Install the bolt and rocker arm for the valve spring requiring removal.
7. Using J 5892-D compress the valve spring. See «Special Tools»(ref-277938-S12463979202008012100000) . Hook the slotted end of J 5892-D under the washer on the rocker arm bolt. See «Special Tools»(ref-277938-S12463979202008012100000) . Apply steady pressure on the valve spring cap until the valve keys are accessible.
8. Use J 38606 when J 5892-D will not fit. See «Special Tools»(ref-277938-S12463979202008012100000) .
9. Remove the valve keys (1).
10. Carefully release the valve spring tension.
11. Remove the J 5892-D or the J 38606 . See «Special Tools»(ref-277938-S12463979202008012100000) .
12. Remove the valve spring cap (2) and valve spring (3).
13. Remove the valve stem oil seal (4).

1. Assemble the valve into the proper valve guide.
2. Select the proper valve stem oil seal for the specific valve guide.
3. Lubricate the valve stem oil seal and the outside diameter of the valve guide with clean engine oil.
4. Assemble the valve stem oil seal onto the valve stem.
5. Using the J 42073 , install the valve stem oil seal onto the valve guide. See «Special Tools»(ref-277938-S12463979202008012100000) . Tap the valve stem oil seal onto the valve guide until the J 42073 bottoms against the valve spring seat. See «Special Tools»(ref-277938-S12463979202008012100000) . Inspect the valve stem oil seal. The valve stem oil seal should not be bottomed against the valve guide. There should be a 1-2 mm (0.03937-0.07874 in) gap between the bottom edge of the valve stem oil seal and the valve guide.
6. Install the valve spring (3).
7. Install the valve spring cap (2) onto the valve spring (3), over the valve stem.
8. Use the J 5892-D in order to compress the valve spring. See «Special Tools»(ref-277938-S12463979202008012100000) . Hook the slotted end of J 5892-D under the washer on the valve rocker arm bolt. See «Special Tools»(ref-277938-S12463979202008012100000) .
9. Apply steady pressure on the valve spring cap until the valve keys are accessible.
10. Use the J 38606 if the clearance does not permit use of the J 5892-D . See «Special Tools»(ref-277938-S12463979202008012100000) .
11. Install the valve stem O-ring seal.
12. Install the valve stem keys. Use grease in order to hold the valve stem keys in place.
13. Carefully release the valve spring pressure, making sure the valve stem keys stay in place.
14. Remove the J 5892-D or the J 38606 . See «Special Tools»(ref-277938-S12463979202008012100000) . Look to ensure that the valve stem keys seat properly in the upper groove of the valve stem. Tap the end of the valve stem with a plastic faced hammer in order to seat the valve stem keys, if necessary.
15. Remove the J 22794 . See «Special Tools»(ref-277938-S12463979202008012100000) .
16. Install the spark plugs. Refer to «Spark Plug Replacement»(ref-277873-S32460422202008012100000) .
17. Install the valve rocker arms. Refer to «Valve Rocker Arm and Push Rod Replacement»(ref-277938-S18489440062008012100000) .

1. Remove the intake manifold. Refer to «Lower Intake Manifold Replacement»(ref-277938-S12104474932008012100000) .
2. Remove the pushrods. Refer to «Valve Rocker Arm and Push Rod Replacement»(ref-277938-S18489440062008012100000) . IMPORTANT: Place the components in a rack so that the components can be installed to their original location.
3. Remove the bolts and lifter pushrod guide.
4. Remove the lifters.
5. Use the J 3049-A in order to remove the stuck valve lifters. See «Special Tools»(ref-277938-S12463979202008012100000) .
6. Use a cleaning solvent and a shop towel to clean any varnish from the valve lifter bores.
7. Inspect the lifter bores for excessive wear or scoring. Replace the engine block if there is excessive wear or deep scoring.
8. Inspect the camshaft for wear or damage. If the wear is questionable remove the camshaft and inspect. Refer to «Camshaft and Bearings Cleaning and Inspection»(ref-277938-S00043505512008012100000) .
9. Clean and inspect the lifters, if necessary. Refer to «Valve Lifters and Guides Cleaning and Inspection»(ref-277938-S03263266352008012100000) .

1. Apply lubricant to the lifter rollers. Refer to «Sealers, Adhesives, and Lubricants»(ref-277938-S13821020292008012100000) for the correct part number.
2. Install the lifters.
3. Install the lifter pushrod guides. Tighten: Tighten the bolts to 16 N.m (12 lb ft).
4. Install the pushrods. Refer to «Valve Rocker Arm and Push Rod Replacement»(ref-277938-S18489440062008012100000) .
5. Install the intake manifold. Refer to «Lower Intake Manifold Replacement»(ref-277938-S12104474932008012100000) .

1. Drain the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(ref-277850-S07555853772008012100000) or «Draining and Filling Cooling System (w/RPO HP2)»(ref-277850-S31192445052008012100000) or «Draining and Filling Cooling System (Vac-N-Fill)»(ref-277850-S00482587952008012100000) .
2. Remove the drive belt. Refer to «Drive Belt Replacement»(ref-277938-S02095851762008012100000) .
3. Remove the lower intake manifold. Refer to «Lower Intake Manifold Replacement»(ref-277938-S12104474932008012100000) .
4. Remove the left exhaust manifold. Refer to «Exhaust Manifold Replacement - Left Side (4.3L Engine)»(ref-277937-S05131508102008012100000) .
5. Remove the left side pushrods. Refer to «Valve Rocker Arm and Push Rod Replacement»(ref-277938-S18489440062008012100000) .
6. Remove the junction block bracket bolt.
7. Position the bracket and wiring harness aside.
8. Loosen the power steering (P/S) pump rear bracket nut.
9. Remove the P/S pump rear bracket front nut.
10. Remove the bolts and nut for the P/S pump bracket.
11. Leave the air conditioning (A/C) compressor, if equipped, and the P/S pump on the bracket.
12. Slide the P/S pump bracket off of the stud and set aside.
13. Remove the P/S pump bracket stud.
14. Remove the harness ground bolt.
15. Position the harness ground (4) and ground strap (5).
16. Remove the engine coolant temperature (ECT) sensor.
17. Remove the spark plugs.
18. Remove the spark plug wire support bolts and support.
19. Remove the cylinder head bolts.
20. Remove the cylinder head.
21. Remove and discard the cylinder head gasket.
22. Remove the cylinder head locator pins, if necessary.
23. Clean and inspect the cylinder head, if necessary. Refer to «Cylinder Head Cleaning and Inspection»(ref-277938-S26138348812008012100000) .
24. Disassemble the cylinder head, if necessary. Refer to «Cylinder Head Disassemble»(ref-277938-S40181263202008012100000) .

1. Assemble the cylinder head, if necessary. Refer to «Cylinder Head Assemble»(ref-277938-S05968016992008012100000) .
2. Install the cylinder head locator pins, if necessary.
3. Install a NEW cylinder head gasket.
4. Install the cylinder head.
5. Apply sealant to the threads of the cylinder head bolts. Refer to «Sealers, Adhesives, and Lubricants»(ref-277938-S13821020292008012100000) for the correct part number.
6. Install the cylinder head bolts until snug.
7. Tighten the cylinder head bolts using the sequence shown. Tighten: Tighten the bolts a first pass to 30 N.m (22 lb ft). Tighten the long bolts (1, 4, 5, 8, 9) a final pass to 75 degrees using J 45059 . See «Special Tools»(ref-277938-S12463979202008012100000) . Tighten the medium bolts (12, 13) a final pass to 65 degrees using J 45059 . See «Special Tools»(ref-277938-S12463979202008012100000) . Tighten the short bolts (2, 3, 6, 7, 10, 11) a final pass to 55 degrees using J 45059 . See «Special Tools»(ref-277938-S12463979202008012100000) .
8. Install the spark plug wire support and bolts. Tighten: Tighten the bolts to 12 N.m (106 lb in).
9. Install the spark plugs.
10. If installing NEW spark plugs measure for the correct gap. Adjust the spark plug gap if necessary. Specification: Spark plug gap to 1.52 mm (0.060 in). Tighten: Tighten the plugs in a USED cylinder head to 15 N.m (11 lb ft). Tighten the plugs on the initial installation of a NEW cylinder head to 30 N.m (22 lb ft).
11. Install the ECT sensor. If reusing the old sensor, apply sealant to the threads. Refer to «Sealers, Adhesives, and Lubricants»(ref-277938-S13821020292008012100000) for the correct part number. Tighten: Tighten the sensor to 20 N.m (15 lb ft).
12. Position the ground strap (5) and harness ground (4).
13. Install the harness ground bolt. Tighten: Tighten the bolt to 16 N.m (12 lb ft).
14. Install the P/S pump bracket stud. Tighten: Tighten the stud to 20 N.m (15 lb ft).
15. Slide the P/S pump bracket rearward.
16. Install the bolts and nuts for the P/S pump bracket.
17. Install the P/S pump rear bracket front nut.
18. Tighten the P/S pump rear bracket nut. Tighten: Tighten the bolts and nuts to 41 N.m (30 lb ft).
19. Position the bracket and wiring harness.
20. Install the junction block bracket bolt. Tighten: Tighten the bolt to 25 N.m (18 lb ft).
21. Install the left side pushrods. Refer to «Valve Rocker Arm and Push Rod Replacement»(ref-277938-S18489440062008012100000) .
22. Install the left exhaust manifold. Refer to «Exhaust Manifold Replacement - Left Side (4.3L Engine)»(ref-277937-S05131508102008012100000) .
23. Install the lower intake manifold. Refer to «Lower Intake Manifold Replacement»(ref-277938-S12104474932008012100000) .
24. Install the drive belt. Refer to «Drive Belt Replacement»(ref-277938-S02095851762008012100000) .
25. Fill the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(ref-277850-S07555853772008012100000) or «Draining and Filling Cooling System (w/RPO HP2)»(ref-277850-S31192445052008012100000) or «Draining and Filling Cooling System (Vac-N-Fill)»(ref-277850-S00482587952008012100000) .

1. Drain the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(ref-277850-S07555853772008012100000) or «Draining and Filling Cooling System (w/RPO HP2)»(ref-277850-S31192445052008012100000) or «Draining and Filling Cooling System (Vac-N-Fill)»(ref-277850-S00482587952008012100000) .
2. Remove the generator bracket. Refer to «Generator Bracket Replacement (4.3L Engine)»(ref-277854-S25339034002008012100000) .
3. Remove the intake manifold. Refer to «Lower Intake Manifold Replacement»(ref-277938-S12104474932008012100000) .
4. Remove the right exhaust manifold. Refer to «Exhaust Manifold Replacement - Right Side (4.3L Engine)»(ref-277937-S04569380022008012100000) .
5. Remove the right pushrods. Refer to «Valve Rocker Arm and Push Rod Replacement»(ref-277938-S18489440062008012100000) .
6. Remove the generator bracket stud from the cylinder head.
7. Remove the spark plugs.
8. Remove the spark plug wire support bolts and support.
9. Remove the cylinder head bolts.
10. Remove the cylinder head.
11. Remove and discard the cylinder head gasket.
12. Remove the cylinder head locator pins, if necessary.
13. Clean and inspect the cylinder head, if necessary. Refer to «Cylinder Head Cleaning and Inspection»(ref-277938-S26138348812008012100000) .
14. Disassemble the cylinder head, if necessary. Refer to «Cylinder Head Disassemble»(ref-277938-S40181263202008012100000) .

1. Assemble the cylinder head, if necessary. Refer to «Cylinder Head Assemble»(ref-277938-S05968016992008012100000) .
2. Install the cylinder head locator pins, if necessary.
3. Install a NEW cylinder head gasket.
4. Install the cylinder head.
5. Apply sealant to the threads of the cylinder head bolts. Refer to «Sealers, Adhesives, and Lubricants»(ref-277938-S13821020292008012100000) for the correct part number.
6. Install the cylinder head bolts until snug.
7. Tighten the cylinder head bolts using the sequence shown. Tighten: Tighten the bolts a first pass to 30 N.m (22 lb ft). Tighten the long bolts (1, 4, 5, 8, 9) a final pass to 75 degrees using J 45059 . See «Special Tools»(ref-277938-S12463979202008012100000) . Tighten the medium bolts (12, 13) a final pass to 65 degrees using J 45059 . See «Special Tools»(ref-277938-S12463979202008012100000) . Tighten the short bolts (2, 3, 6, 7, 10, 11) a final pass to 55 degrees using J 45059 . See «Special Tools»(ref-277938-S12463979202008012100000) .
8. Install the spark plug wire support and bolts. Tighten: Tighten bolts to 12 N.m (106 lb in).
9. Install the spark plugs.
10. If installing NEW spark plugs measure for the correct gap. Adjust the spark plug gap, if necessary. Specification: Spark plug gap to 1.52 mm (0.060 in). Tighten: Tighten the plugs on a USED cylinder head to 15 N.m (11 lb ft). Tighten the plugs on the initial installation of a NEW cylinder head to 30 N.m (22 lb ft).
11. Install the generator bracket stud. Tighten: Tighten the stud to 20 N.m (15 lb ft).
12. Install the right pushrods. Refer to «Valve Rocker Arm and Push Rod Replacement»(ref-277938-S18489440062008012100000) .
13. Install the exhaust manifold. Refer to «Exhaust Manifold Replacement - Right Side (4.3L Engine)»(ref-277937-S04569380022008012100000) .
14. Install the intake manifold. Refer to «Lower Intake Manifold Replacement»(ref-277938-S12104474932008012100000) .
15. Install the generator bracket. Refer to «Generator Bracket Replacement (4.3L Engine)»(ref-277854-S25339034002008012100000) .
16. Fill the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(ref-277850-S07555853772008012100000) or «Draining and Filling Cooling System (w/RPO HP2)»(ref-277850-S31192445052008012100000) or «Draining and Filling Cooling System (Vac-N-Fill)»(ref-277850-S00482587952008012100000) .

1. Remove the drive belt. Refer to «Drive Belt Replacement»(ref-277938-S02095851762008012100000) .
2. Remove the cooling fan. Refer to «Fan Replacement (Diesel)»(ref-277850-S12386650402008012100000) or «Fan Replacement (Mechanical)»(ref-277850-S26259650622008012100000) . NOTE: To prevent damage to the end of the crankshaft when using a crankshaft balancer removal tool install a bolt in the crankshaft. Use a shorter bolt with the same threads as the crankshaft balancer bolt. This bolt will allow a place for the tool to push against. The shorter bolt is to keep from going past the threads in the crankshaft and damaging the crankshaft threads.
3. Remove the crankshaft balancer bolt and washer.
4. Remove the crankshaft pulley bolts and pulley.
5. Using J 23523-F , remove the crankshaft balancer. See «Special Tools»(ref-277938-S12463979202008012100000) . Install the J 23523-F plate and bolts onto the crankshaft balancer. See «Special Tools»(ref-277938-S12463979202008012100000) . Tighten: Tighten the bolts to 25 N.m (18 lb ft). Install the J 23523-F forcing screw into the plate. See «Special Tools»(ref-277938-S12463979202008012100000) . Rotate the J 23523-F forcing screw clockwise in order to remove the crankshaft balancer. See «Special Tools»(ref-277938-S12463979202008012100000) .
6. Remove the J 23523-F from the crankshaft balancer. See «Special Tools»(ref-277938-S12463979202008012100000) .
7. Note the position and length of any crankshaft balancer weights, if necessary.
8. Clean and inspect the crankshaft balancer, if necessary. Refer to «Crankshaft Balancer Cleaning and Inspection»(ref-277938-S10937001032008012100000) .

1. Apply a small amount of grease to the crankshaft front cover seal sealing surface if reusing the seal.
2. Ensure that the crankshaft balancer weight(s) is installed in the proper location, if necessary.
3. Apply a small amount of adhesive into the crankshaft balancer keyway in order to seal the crankshaft balancer keyway and crankshaft joint. Refer to «Sealers, Adhesives, and Lubricants»(ref-277938-S13821020292008012100000) for the correct part number.
4. Align the keyway of the crankshaft balancer with the crankshaft balancer key.
5. Install the crankshaft balancer onto the end of the crankshaft.
6. Using J 23523-F , press the crankshaft balancer onto the crankshaft. See «Special Tools»(ref-277938-S12463979202008012100000) . Install the J 23523-F plate and bolts onto the front of the crankshaft balancer. See «Special Tools»(ref-277938-S12463979202008012100000) . Tighten: Tighten the bolts to 25 N.m (18 lb ft). Install the J 23523-F forcing screw into the end for the crankshaft. See «Special Tools»(ref-277938-S12463979202008012100000) . Install the J 23523-F bearing, the washer, and the nut onto the forcing screw. See «Special Tools»(ref-277938-S12463979202008012100000) . Rotate the J 23523-F nut clockwise until the crankshaft balancer hub is completely seated against the crankshaft position sensor reluctor ring. See «Special Tools»(ref-277938-S12463979202008012100000) .
7. Remove the J 23523-F . See «Special Tools»(ref-277938-S12463979202008012100000) .
8. Install the crankshaft pulley and bolts. Finger tighten all bolts until snug in order to fully seat the pulley.
9. Tighten the bolts. Tighten: Tighten the bolts to 58 N.m (43 lb ft).
10. Ensure that the crown of the crankshaft balancer washer (2) is faced away from the engine.
11. Install the crankshaft balancer washer and bolt. Tighten: Tighten the bolt to 95 N.m (70 lb ft).
12. Install the cooling fan. Refer to «Fan Replacement (Diesel)»(ref-277850-S12386650402008012100000) or «Fan Replacement (Mechanical)»(ref-277850-S26259650622008012100000) .
13. Install the drive belt. Refer to «Drive Belt Replacement»(ref-277938-S02095851762008012100000) .

1. Remove the crankshaft balancer. Refer to «Crankshaft Balancer Replacement»(ref-277938-S28690890442008012100000) .
2. Use a suitable seal puller, remove the crankshaft front oil seal.
3. Inspect the engine front cover seal bore area for damage.

1. Lubricate the exterior of the NEW seal with clean engine oil.
2. Using J 35468 and a hammer, install the crankshaft front oil seal. See «Special Tools»(ref-277938-S12463979202008012100000) .
3. Ensure the crankshaft front oil seal is flush and square to the engine front cover.
4. Install the crankshaft balancer. Refer to «Crankshaft Balancer Replacement»(ref-277938-S28690890442008012100000) .

1. Remove the water pump. Refer to «Water Pump Replacement (4.3L)»(ref-277850-S21869186492008012100000) .
2. Remove the crankshaft balancer. Refer to «Crankshaft Balancer Replacement»(ref-277938-S28690890442008012100000) .
3. Remove the oil pan. Refer to «Oil Pan Replacement»(ref-277938-S40752598632008012100000) .
4. Remove the engine shield bolts and shield.
5. Disconnect the crankshaft position (CKP) sensor electrical connector (5).
6. Remove the CKP sensor bolt and sensor.
7. Remove and discard the CKP sensor O-ring seal.
8. Remove the front cover bolts.
9. Remove and discard the front cover.
10. Clean all sealing surfaces.

1. Install a NEW front cover.
2. Install the front cover bolts. Tighten: Tighten the bolts to 12 N.m (106 lb in).
3. Lubricate a NEW CKP sensor O-ring seal with clean engine oil.
4. Install the NEW O-ring seal onto the CKP sensor.
5. Install the CKP sensor and bolt. Tighten: Tighten the bolt to 8 N.m (71 lb in).
6. Connect the CKP sensor electrical connector (5).
7. Install the engine shield and bolts. Tighten: Tighten the bolts to 20 N.m (15 lb ft).
8. Install the oil pan. Refer to «Oil Pan Replacement»(ref-277938-S40752598632008012100000) .
9. Install the crankshaft balancer. Refer to «Crankshaft Balancer Replacement»(ref-277938-S28690890442008012100000) .
10. Install the water pump. Refer to «Water Pump Replacement (4.3L)»(ref-277850-S21869186492008012100000) .

1. Remove the engine front cover. Refer to «Engine Front Cover Replacement»(ref-277938-S06977473012008012100000) .
2. Remove the crankshaft position (CKP) sensor reluctor ring.

1. Install the CKP sensor reluctor ring. Align the keyway on the CKP sensor reluctor ring with the key in the crankshaft. Using J 5590 , push the CKP sensor reluctor ring onto the crankshaft until completely seated against the crankshaft sprocket. See «Special Tools»(ref-277938-S12463979202008012100000) .
2. Install the engine front cover. Refer to «Engine Front Cover Replacement»(ref-277938-S06977473012008012100000) .

Timing Chain, Sprockets, and/or Tensioner Replacement

Tools Required

1. J 5590 Rear Pinion Bearing Race Installer. See «Special Tools»(ref-277938-S12463979202008012100000) .
2. J 5825-A Crankshaft Gear Remover. See «Special Tools»(ref-277938-S12463979202008012100000) .

Note. In order to rotate the engine install a bolt with the same threads as the crankshaft, but do not use the crankshaft balancer bolt or a bolt longer than 1 inch, in the crankshaft. Failing to do so will cause damage to the bolt threads and the crankshaft threaded hole when removing the bolt.

1. Remove the crankshaft position (CKP) sensor reluctor ring. Refer to «Crankshaft Position Reluctor Ring Replacement»(ref-277938-S19197499972008012100000) .
2. Install a 7/16-20 x 1 inch bolt into the end of the crankshaft.
3. Rotate the crankshaft until: The timing marks on both sprockets line up. The number 4 cylinder is at top dead center (TDC) of the compression stroke.
4. Unsnap the timing chain tensioner shoe from the pin (1).
5. Remove the camshaft sprocket bolts.
6. Remove the camshaft sprocket and the camshaft timing chain.
7. Using J 5825-A and an open end wrench, remove the crankshaft sprocket. See «Special Tools»(ref-277938-S12463979202008012100000) .
8. Remove the crankshaft balancer key.
9. If necessary, remove the timing chain tensioner bracket bolt and bracket.
10. Clean and inspect the timing chain and sprockets, if necessary. Refer to «Timing Chain and Sprockets Cleaning and Inspection»(ref-277938-S23112102332008012100000) .

1. If necessary, install the timing chain tensioner bracket and bolt. Tighten: Tighten the bolt to 12 N.m (106 lb in).
2. Install the key into the crankshaft keyway. The crankshaft balancer key should be parallel to the crankshaft or with a slight incline.
3. Align the keyway of the crankshaft sprocket with the crankshaft balancer key.
4. Using J 5590 , install the crankshaft sprocket. See «Special Tools»(ref-277938-S12463979202008012100000) .
5. Install the camshaft sprocket and the camshaft timing chain. Wrap the timing chain around the crankshaft sprocket and position to the drivers side of the engine.
6. Install the timing chain tensioner shoe onto the bracket and position the top of the shoe under the tab at the top of the bracket.
7. Insert the camshaft timing chain sprocket into the timing chain and position so when the camshaft timing chain sprocket is installed on the camshaft, the camshaft timing marks will line up.
8. Install the camshaft sprocket bolts. Tighten: Tighten the bolts to 25 N.m (18 lb ft).
9. Ensure that the crankshaft sprocket is aligned at the 12 o'clock position and camshaft sprocket is aligned at the 6 o'clock position.
10. Remove the bolt that was installed in the end of the crankshaft.
11. Install the CKP sensor reluctor ring. Refer to «Crankshaft Position Reluctor Ring Replacement»(ref-277938-S19197499972008012100000) .

Balance Shaft Replacement

Tools Required

1. J 8092 Universal Driver Handle
2. J 36996 Balance Shaft Installer. See «Special Tools»(ref-277938-S12463979202008012100000) .
3. J 45059 Angle Meter. See «Special Tools»(ref-277938-S12463979202008012100000) .

1. Remove the radiator. Refer to «Radiator Replacement (4.3L, 4.8, 5.3, and 6.0L)»(ref-277850-S42000307572008012100000) .
2. Remove the air conditioning (A/C) condenser. Refer to «Condenser Replacement»(ref-277853-S35551967062008012100000) .
3. Remove the lifter pushrod guide. Refer to «Valve Lifter Replacement»(ref-277938-S29867338042008012100000) .
4. Remove the timing chain and camshaft sprocket. Refer to «Timing Chain, Sprockets, and/or Tensioner Replacement»(ref-277938-S05858876362008012100000) .
5. Remove the balance shaft drive gear.
6. Remove the balance shaft driven gear bolt. Use a wrench in order to secure the balance shaft. Place the wrench onto the balance shaft near to the balance shaft front bearing. Remove the balance shaft bolt. Remove the wrench from the balance shaft.
7. Remove the balance shaft driven gear.
8. Remove the balance shaft retainer bolts and retainer.
9. Use a soft-faced hammer in order to remove the balance shaft from the engine block.
10. Clean and inspect the balance shaft, if necessary. Refer to «Balance Shaft Cleaning and Inspection»(ref-277938-S04166474782008012100000) .

1. Apply clean engine oil to the balance shaft front bearing.
2. Using J 36996 and J 8092 , install the balance shaft. See «Special Tools»(ref-277938-S12463979202008012100000) .
3. Install the balance shaft retainer and bolts. Tighten: Tighten the bolts to 12 N.m (106 lb in).
4. Install the balance shaft driven gear.
5. If reusing the fastener, apply threadlocker to the threads of the balance shaft driven gear bolt. Refer to «Sealers, Adhesives, and Lubricants»(ref-277938-S13821020292008012100000) for the correct part number.
6. Install the balance shaft driven gear bolt. Use a wrench to secure the balance shaft. Place the wrench onto the balance shaft near to the balance shaft front bearing. Install the balance shaft driven gear bolt. Tighten: Tighten the bolt a first pass to 20 N.m (15 lb ft). Tighten the bolt a final pass an additional 35 degrees using J 45059 . See «Special Tools»(ref-277938-S12463979202008012100000) .
7. Remove the wrench from the balance shaft.
8. Rotate the balance shaft by hand in order to ensure that there is clearance between the balance shaft and the valve lifter pushrod guide. If the balance shaft does not rotate freely, check to ensure that the retaining ring on the balance shaft front bearing is seated on the case.
9. Install the balance shaft drive gear. DO NOT install the camshaft sprocket bolts at this time.
10. Rotate the camshaft so that the timing mark on the balance shaft drive gear is in the 12 o'clock position.
11. Remove the balance shaft drive gear.
12. Rotate the balance shaft so that the timing mark on the balance shaft driven gear is in the 6 o'clock position.
13. Position the balance shaft drive gear onto the engine camshaft.
14. Look to ensure that the balance shaft drive gear and the balance shaft driven gear timing marks are aligned.
15. Install the timing chain and the camshaft sprocket. Refer to «Timing Chain, Sprockets, and/or Tensioner Replacement»(ref-277938-S05858876362008012100000) .
16. Install the valve lifter pushrod guide. Refer to «Valve Lifter Replacement»(ref-277938-S29867338042008012100000) .
17. Install the A/C condenser. Refer to «Condenser Replacement»(ref-277853-S35551967062008012100000) .
18. Install the radiator. Refer to «Radiator Replacement (4.3L, 4.8, 5.3, and 6.0L)»(ref-277850-S42000307572008012100000) .

Balance Shaft Bearing and/or Bushing Replacement

Tools Required

1. J 26941 Bushing and Bearing Remover
2. J 38834 Balance Shaft Service Kit. See «Special Tools»(ref-277938-S12463979202008012100000) .

1. Remove the balance shaft. Refer to «Balance Shaft Replacement»(ref-277938-S28972333332008012100000) .
2. Using J 26941 and the J 38834 , remove the balance shaft rear bearing. See «Special Tools»(ref-277938-S12463979202008012100000) . Install the J 26941 legs behind the balance shaft rear bearing and secure. Install the J 38834-1 with the short threaded end through the balance shaft bore in the front of the engine block. Install J 38834-1 into the J 26941 . Slide the J 38834-2 onto the J 38834-1 and into the balance shaft bore of the engine block. Install the J 38834 bearing, washer, and nut onto the J 38834-1. See «Special Tools»(ref-277938-S12463979202008012100000) . Using a wrench, secure the J 38834-1, and then rotate the J 38834 nut clockwise until the balance shaft rear bearing is removed from the engine block. See «Special Tools»(ref-277938-S12463979202008012100000) . Remove the J 26941 from the balance shaft rear bearing.
3. Discard the balance shaft rear bearing.

1. Using J 38834 , install the balance shaft rear bearing. See «Special Tools»(ref-277938-S12463979202008012100000) . Install the J 38834-3 onto the short threaded end of the J 38834-1. Install the J 38834 nut, the washer, and the bearing on the long threaded end of the J 38834-1. See «Special Tools»(ref-277938-S12463979202008012100000) . Install the J 38834-2 onto the J 38834-1 so that the smaller diameter of the J 38834-2 will be facing the front of the engine block. Install the J 38834-2 on the inside of the balance shaft front bearing bore. Lubricate the NEW balance shaft rear bearing with clean engine oil. Install the balance shaft rear bearing onto the J 38834-2. Align the balance shaft rear bearing for installation. Using a wrench, secure the J 38834-1 into place. Rotate the J 38834 nut until the balance shaft rear bearing is properly and completely pushed into the balance shaft rear bearing bore. See «Special Tools»(ref-277938-S12463979202008012100000) .
2. Remove the J 38834 . See «Special Tools»(ref-277938-S12463979202008012100000) .
3. Install the balance shaft. Refer to «Balance Shaft Replacement»(ref-277938-S28972333332008012100000) .

1. Remove the radiator. Refer to «Radiator Replacement (4.3L, 4.8, 5.3, and 6.0L)»(ref-277850-S42000307572008012100000) .
2. Remove the air conditioning (A/C) condenser. Refer to «Condenser Replacement»(ref-277853-S35551967062008012100000) .
3. Remove the lifters. Refer to «Valve Lifter Replacement»(ref-277938-S29867338042008012100000) .
4. Remove the timing chain and the camshaft sprocket. Refer to «Timing Chain, Sprockets, and/or Tensioner Replacement»(ref-277938-S05858876362008012100000) .
5. Remove the balance shaft drive gear.
6. Remove the camshaft retainer bolts and retainer.
7. Remove the engine camshaft. Install the three 5/16-18 x 4.0 inch bolts into the engine camshaft front bolt holes. Using the bolts as a handle, carefully rotate and pull the engine camshaft out of the camshaft bearings. Remove the bolts from the front of the engine camshaft. Clean and inspect the camshaft and/or bearings, if necessary. Refer to «Camshaft and Bearings Cleaning and Inspection»(ref-277938-S00043505512008012100000) .

1. Apply lubricant or engine oil supplement to the following components: The engine camshaft lobes The camshaft bearing journals The camshaft bearings Refer to «Sealers, Adhesives, and Lubricants»(ref-277938-S13821020292008012100000) for the correct part number.
2. Install three 5/16-18 x 4.0 inch bolts into the engine camshaft front bolt holes.
3. Using the bolts as a handle, install the engine camshaft.
4. Remove the 3 bolts from the front of the engine camshaft.
5. If reusing the fasteners, apply threadlocker to the threads of the camshaft retainer bolts. Refer to «Sealers, Adhesives, and Lubricants»(ref-277938-S13821020292008012100000) for the correct part number.
6. Install the camshaft retainer and bolts. Tighten: Tighten the bolts to 12 N.m (106 lb in).
7. Install the balance shaft drive gear. Refer to «Balance Shaft Installation»(ref-277938-S19885128502008012100000) , for alignment of the balance shaft drive gear and the driven gear.
8. Install the timing chain and camshaft sprocket. Refer to «Timing Chain, Sprockets, and/or Tensioner Replacement»(ref-277938-S05858876362008012100000) .
9. Install the lifters. Refer to «Valve Lifter Replacement»(ref-277938-S29867338042008012100000) .
10. Install the A/C condenser. Refer to «Condenser Replacement»(ref-277853-S35551967062008012100000) .
11. Install the radiator. Refer to «Radiator Replacement (4.3L, 4.8, 5.3, and 6.0L)»(ref-277850-S42000307572008012100000) .

1. Raise and suitably support the vehicle. Refer to «Lifting and Jacking the Vehicle»(ref-277851-S21776392712008012100000) .
2. Remove the oil pan drain plug and drain the oil into a suitable container.
3. Remove the oil filter.
4. Remove the oil filter adapter.

1. Install the oil pan drain plug into the drain pan. Tighten: Tighten the plug to 25 N.m (18 lb ft).
2. Install the oil filter adapter. Tighten: Tighten the adapter to 55 N.m (41 lb ft).
3. Install the oil filter. Tighten: Tighten the filter to 30 N.m (22 lb ft).
4. Lower the vehicle.
5. Fill the engine with the proper quantity and quality of engine oil. Refer to «Approximate Fluid Capacities»(ref-277950-S03550976542008012100000) .

1. Raise and suitably support the vehicle. Refer to «Lifting and Jacking the Vehicle»(ref-277851-S21776392712008012100000) .
2. Position a suitable container under the vehicle to catch the oil.
3. Remove the oil filter.
4. Using a suitable prying tool, remove the oil filter bypass valve.
5. Clean and inspect the valve bore for damage.

1. Install a NEW oil filter bypass valve using the following procedure: Use a brass drift that is the same diameter as the outside diameter of the oil filter bypass valve. Install the oil filter bypass valve into the oil gallery bore until slightly below flush with the surface of the engine block. Using a pointed punch, stake the engine block area around the oil filter bypass valve. Stake in 3 locations 120 degrees apart.
2. Install the oil filter. Refer to «Engine Oil and Oil Filter Replacement»(ref-277938-S40832981612008012100000) .
3. Lower the vehicle.

1. Raise and suitably support the vehicle. Refer to «Lifting and Jacking the Vehicle»(ref-277851-S21776392712008012100000) .
2. If equipped, remove the oil pan skid plate bolts and plate.
3. Remove the drain plug and drain the oil into a suitable container.
4. Remove the oil filter.
5. If equipped with (2WD), remove the crossmember bolts and bar.
6. If equipped with 4WD, remove the crossmember bolts and bar.
7. If equipped with 4WD, remove the front differential carrier. Refer to «Differential Carrier Assembly Replacement»(ref-277880-S42731471152008012100000) .
8. Remove the battery cable bracket bolts.
9. Remove the starter. Refer to «Starter Motor Replacement (4.3L Engine)»(ref-277854-S36909298662008012100000) .
10. Remove the transmission cover.
11. Remove the positive battery cable clip bolt (2).
12. Disconnect the oil level sensor electrical connector (7).
13. Remove the manual transmission bolts, if equipped.
14. Remove the automatic transmission bolts, if equipped.
15. Remove and discard the oil level sensor.
16. Remove the oil pan bolts and nuts.
17. Remove the oil pan.
18. Remove and discard the oil pan gasket.
19. Clean and inspect the oil pan, if necessary. Refer to «Oil Pan Cleaning and Inspection»(ref-277938-S09289567122008012100000) .

Note. Any time the transmission and the engine oil pan are off of the engine at the same time, install the transmission before the oil pan. This is to allow for the proper oil pan alignment. Failure to achieve the correct oil pan alignment can result in transmission failure.

1. Apply a 5 mm (0.197 in) wide and 25 mm (1.0 in) long bead of adhesive to both the right and left sides of the front cover to engine block junction at the oil pan sealing surfaces. Refer to «Sealers, Adhesives, and Lubricants»(ref-277938-S13821020292008012100000) for the correct part number.
2. Apply a 5 mm (0.197 in) wide and 25 mm (1.0 in) long bead of adhesive to the entire length of rear oil seal housing to engine block junction at the oil pan sealing surfaces. Refer to «Sealers, Adhesives, and Lubricants»(ref-277938-S13821020292008012100000) for the correct part number.
3. Install a NEW oil pan gasket into the groove in the oil pan.
4. Install the oil pan. Press the oil pan gasket into the grooves of the engine front cover and crankshaft rear oil seal housing.
5. Slide the oil pan back against a suitable straight edge.
6. Install the oil pan bolts and nuts until snug.
7. Measure the oil pan-to-transmission housing clearance using a feeler gage and a straight edge. Use the feeler gage to check the clearance at the oil pan-to-transmission housing measurement points (1). If the clearance exceeds 0.3 mm (0.011 in) at any of the oil pan-to-transmission housing measurement points (1), then repeat the step until the oil pan-to-transmission housing clearance is within specifications. The oil pan must always be forward of the rear face of the engine block.
8. Tighten the oil pan bolts and nuts in the sequence shown. Tighten: Tighten the bolts to 25 N.m (18 lb ft).
9. Measure the clearance at the oil pan-to-transmission housing measurement points in order to ensure proper alignment.
10. Install a NEW drain plug O-ring seal onto the drain plug.
11. Install the drain plug. Tighten: Tighten the plug to 25 N.m (18 lb ft).
12. Install a NEW oil level sensor. Tighten: Tighten the sensor to 13 N.m (115 lb in).
13. Install the transmission cover. Tighten: Tighten the bolts to 12 N.m (106 lb in).
14. Install the automatic transmission bolts, if equipped.
15. Install the manual transmission bolts, if equipped. Tighten: Tighten the bolts to 50 N.m (37 lb ft).
16. Install the positive battery cable clip bolt (2). Tighten: Tighten the bolt to 9 N.m (80 lb in).
17. Install the starter. Refer to «Starter Motor Replacement (4.3L Engine)»(ref-277854-S36909298662008012100000) .
18. Connect the oil level sensor electrical connector (7).
19. Install the battery cable bracket bolts. Tighten: Tighten the bolts to 12 N.m (106 lb in).
20. If equipped with 2WD, Install the crossmember and bolts. Tighten: Tighten the bolts to 100 N.m (74 lb ft).
21. Install the front differential carrier, if equipped with 4WD. Refer to «Differential Carrier Assembly Replacement»(ref-277880-S42731471152008012100000) .
22. If equipped with 4WD, install the crossmember and bolts. Tighten: Tighten the bolts to 100 N.m (74 lb ft).
23. If equipped, install the oil pan skid plate and bolts. Tighten: Tighten the bolts to 20 N.m (15 lb ft).
24. Lubricate the oil filter gasket with clean engine oil.
25. Install the oil filter. Tighten: Tighten the filter to 30 N.m (22 lb ft).
26. Lower the vehicle.
27. Fill the engine with the proper capacity and quality of engine oil. Refer to «Approximate Fluid Capacities»(ref-277950-S03550976542008012100000) .

1. Remove the distributor. Refer to «Distributor Replacement»(ref-277873-S23388997282008012100000) .
2. Disconnect the fuel pump/oil pressure sensor electrical connector (3).
3. Using J 41712 , remove the fuel pump/oil pressure sensor. See «Special Tools»(ref-277938-S12463979202008012100000) .
4. Remove the fuel pump/oil pressure sensor fitting, if necessary.

1. If installing the old fitting, apply sealant to the threads of the fitting. Refer to «Sealers, Adhesives, and Lubricants»(ref-277938-S13821020292008012100000) for the correct part number.
2. Install the fitting until snug, if necessary.
3. Tighten the fuel pump/oil pressure sensor fitting. Tighten: Tighten the fitting to 15 N.m (11 lb ft). Increase torque until the centerline of the fitting (1) is 50 degrees from the centerline of the crankshaft (2).
4. If installing the old sensor, apply sealant to the threads of the sensor. Refer to «Sealers, Adhesives, and Lubricants»(ref-277938-S13821020292008012100000) for the correct part number.
5. Using J 41712 , install the sensor. See «Special Tools»(ref-277938-S12463979202008012100000) . Tighten: Tighten the sensor to 30 N.m (22 lb ft).
6. Connect the fuel pump/oil pressure sensor electrical connector (3).
7. Install the distributor. Refer to «Distributor Replacement»(ref-277873-S23388997282008012100000) .
8. Check and adjust the engine oil level, if necessary.

1. Raise and suitably support the vehicle. Refer to «Lifting and Jacking the Vehicle»(ref-277851-S21776392712008012100000) .
2. Remove the drain plug and drain the oil into a suitable container.
3. Disconnect the oil level sensor electrical connector (7).
4. Remove the oil level sensor.

1. Install the drain plug. Tighten: Tighten the plug to 25 N.m (18 lb ft).
2. Install the oil level sensor. Tighten: Tighten the sensor to 20 N.m (15 lb ft).
3. Connect the oil level sensor electrical connector (7).
4. Lower the vehicle.
5. Fill the engine with the proper quantity and grade of oil. Refer to «Approximate Fluid Capacities»(ref-277950-S03550976542008012100000) .

1. Remove the oil level indicator.
2. Remove the right exhaust manifold. Refer to «Exhaust Manifold Replacement - Right Side (4.3L Engine)»(ref-277937-S04569380022008012100000) .
3. Remove the oil level indicator tube bolt.
4. Remove the oil level indicator tube using a twisting motion.
5. Clean the old sealer from the indicator tube and engine block.

1. Apply sealant around the indicator tube 13 mm (0.5 in) below the tube bead. Refer to «Sealers, Adhesives, and Lubricants»(ref-277938-S13821020292008012100000) for the correct part number.
2. Install the indicator tube. Rotate the oil level indicator tube into position. NOTE: Refer to «Fastener Notice»(ref-277849-S30907907212008012100000) .
3. Install the indicator tube bolt. Tighten: Tighten the bolt to 12 N.m (106 lb in).
4. Install the right exhaust manifold. Refer to «Exhaust Manifold Replacement - Right Side (4.3L Engine)»(ref-277937-S04569380022008012100000) .
5. Install the oil level indicator.

1. Remove the oil pan. Refer to «Oil Pan Replacement»(ref-277938-S40752598632008012100000) .
2. Remove the oil pump bolt.
3. Remove the oil pump.
4. Inspect the oil pump locator pins for damage, and replace if required.
5. Clean and inspect the oil pump, if necessary. Refer to «Oil Pump Cleaning and Inspection»(ref-277938-S27710694292008012100000) .

1. Inspect for properly installed oil pump locator pins.
2. Install the oil pump. Position the oil pump onto the locator pins.
3. Install the oil pump bolt. Tighten: Tighten the bolt to 90 N.m (66 lb ft).
4. Install the oil pan. Refer to «Oil Pan Replacement»(ref-277938-S40752598632008012100000) .

1. Remove the flywheel. Refer to «Engine Flywheel Replacement»(ref-277938-S13572816472008012100000) .
2. Insert a flat-tipped screwdriver into the access notches and carefully pry the seal from the housing.
3. Discard the seal.
4. Clean off any dirt or rust in the area.

1. Apply 2 to 3 drops of clean engine oil to the bore of the housing.
2. Apply 2 to 3 drops of clean engine oil to the outside diameter of the engine flywheel pilot flange.
3. Apply 1 drop of clean engine oil to the outside diameter of the flywheel locator pin.
4. Apply 2 to 3 drops of clean engine oil to the crankshaft seal surface.
5. Inspect the J 35621-B flange for imperfections that may damage the NEW seal. See «Special Tools»(ref-277938-S12463979202008012100000) . Minor imperfections may be removed with a fine grade emery cloth.
6. Remove the sleeve from the seal.
7. Apply 2 to 3 drops of clean engine oil to the outside diameter of the seal.
8. Install the seal onto the J 35621-B . See «Special Tools»(ref-277938-S12463979202008012100000) .
9. Install the J 35621-B onto the rear of the crankshaft and hand tighten the tool bolts until snug. See «Special Tools»(ref-277938-S12463979202008012100000) .
10. Install the seal onto the crankshaft and into the housing: Turn the J 35621-B wing nut clockwise until the seal is installed close to flush and square to the housing. See «Special Tools»(ref-277938-S12463979202008012100000) . Increased resistance will be felt when the seal has reached the bottom of the housing bore. Turn the J 35621-B wing nut counterclockwise to release the J 35621-B from the seal. See «Special Tools»(ref-277938-S12463979202008012100000) .
11. Remove the J 35621-B . See «Special Tools»(ref-277938-S12463979202008012100000) .
12. Wipe off any excess engine oil with a clean rag.
13. Install the engine flywheel. Refer to «Engine Flywheel Replacement»(ref-277938-S13572816472008012100000) .

1. Remove the oil pan. Refer to «Oil Pan Replacement»(ref-277938-S40752598632008012100000) .
2. Remove the engine flywheel. Refer to «Engine Flywheel Replacement»(ref-277938-S13572816472008012100000) .
3. Remove the housing bolts and nut.
4. Remove the housing.
5. Remove and discard the housing gasket.
6. Clean all the sealing surfaces.
7. Inspect and replace the housing for warping, cracks, wear, or damage.

1. Install a NEW housing gasket.
2. Install the NEW housing with the seal using the following procedure. IMPORTANT: Do not oil or grease the seal lip or the crankshaft seal area. Leave the sleeve in the seal and use the sleeve as a guide to ease installing the seal lip over the end of the crankshaft. Push the housing fully onto the crankshaft until the housing is against the seal gasket and the engine. Remove the sleeve.
3. Install the crankshaft rear oil seal housing bolts and nut. Tighten: Tighten the bolts and nut to 12 N.m (106 lb in).
4. Install the engine flywheel. Refer to «Engine Flywheel Replacement»(ref-277938-S13572816472008012100000) .
5. Install the oil pan. Refer to «Oil Pan Replacement»(ref-277938-S40752598632008012100000) .

1. Remove the automatic transmission, if equipped. Refer to «Transmission Replacement (4.8L, 5.3L, and 6.0L Engines)»(ref-277952-S42126619312008012100000) or «Transmission Replacement (5.3L Engine w/RPO HP2)»(ref-277952-S15346040172008012100000) .
2. Remove the clutch, if equipped. Refer to «Clutch Assembly Replacement»(ref-277945-S32449211492008012100000) .
3. Remove the flywheel bolts.
4. Remove the flywheel (1 or 2).
5. If equipped with a manual transmission, note the position of any flywheel weights for assembly.
6. Clean and inspect the flywheel, if necessary. Refer to «Engine Flywheel Cleaning and Inspection»(ref-277938-S15961123262008012100000) .

1. Note the position of the old flywheel weights and install the NEW flywheel weights as required. A properly installed flywheel weight will be flush or slightly below flush with the face of the flywheel.
2. Install the flywheel (1 or 2). Align the flywheel locator hole to the flywheel locator pin.
3. Install the flywheel bolts. Tighten: Tighten the bolts in the sequence shown to 100 N.m (74 lb ft).
4. Install the clutch, if equipped. Refer to «Clutch Assembly Replacement»(ref-277945-S32449211492008012100000) .
5. Install the automatic transmission, if equipped. Refer to «Transmission Replacement (4.8L, 5.3L, and 6.0L Engines)»(ref-277952-S42126619312008012100000) or «Transmission Replacement (5.3L Engine w/RPO HP2)»(ref-277952-S15346040172008012100000) .

1. 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).
2. Disconnect the negative battery cable. Refer to «Battery Negative Cable Disconnection and Connection (Auxiliary Battery)»(ref-277854-S37314824542008012100000) or «Battery Negative Cable Disconnection and Connection (Single Battery)»(ref-277854-S29426527292008012100000) .
3. Drain the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(ref-277850-S07555853772008012100000) or «Draining and Filling Cooling System (w/RPO HP2)»(ref-277850-S31192445052008012100000) or «Draining and Filling Cooling System (Vac-N-Fill)»(ref-277850-S00482587952008012100000) .
4. Remove the fuel pipes/hoses. Refer to «Fuel Hose/Pipes Replacement - Engine Compartment»(ref-277873-S29478769382008012100000) .
5. Remove the lower fan shroud. Refer to «Engine Coolant Fan Lower Shroud Replacement»(ref-277850-S42558773622008012100000) .
6. Remove the drive belt. Refer to «Drive Belt Replacement»(ref-277938-S02095851762008012100000) .
7. Raise and suitably support the vehicle. Refer to «Lifting and Jacking the Vehicle»(ref-277851-S21776392712008012100000) .
8. If equipped, remove the oil pan skid plate bolts and plate.
9. If equipped, remove the engine shield. Refer to «Engine Protection Shield Replacement»(ref-277879-S31943219262008012100000) .
10. Remove the starter. Refer to «Starter Motor Replacement (4.3L Engine)»(ref-277854-S36909298662008012100000) .
11. Remove the transmission cover.
12. Remove the positive battery cable clip bolt (2).
13. Remove the catalytic converter. Refer to «Catalytic Converter Replacement (4.3L, 4.8L, and 5.3L Engines)»(ref-277937-S01902361742008012100000) .
14. Remove the battery cable bracket bolts.
15. Disconnect the crankshaft position (CKP) sensor electrical connector (5) and remove the harness from the retainer clip.
16. Remove the ground bolt (3) holding the negative battery cable (6) and ground cable (4) to the engine.
17. If equipped, remove the torque converter bolts.
18. Remove the transmission bolts.
19. Lower the vehicle.
20. Reposition the radiator inlet hose clamp.
21. Remove the radiator inlet hose from the thermostat housing.
22. Reposition the radiator outlet hose clamps.
23. Remove the radiator outlet hose from the surge tank.
24. Remove the radiator outlet hose from the water pump.
25. If equipped, disconnect the cruise control cable from the throttle lever.
26. If equipped, remove the cruise control cable from the accelerator control cable bracket.
27. Remove the accelerator cable from the throttle body lever.
28. Remove the accelerator cable from the accelerator control cable bracket.
29. Remove the accelerator cable from the throttle body lever.
30. Remove the accelerator control cable bracket nuts.
31. Remove the accelerator control cable bracket with the cables attached, from the throttle body.
32. Reposition and secure the bracket and cable out of the way.
33. If equipped, remove the air conditioning (A/C) hoses. Refer to «Discharge Hose Replacement (LB7)»(ref-277853-S28439312062008012100000) or «Discharge Hose Replacement (LR4, LM7, LQ4, L18)»(ref-277853-S31817298582008012100000) and «Suction Hose Replacement (LB7 w/Denso)»(ref-277853-S32123682532008012100000) or «Suction Hose Replacement (LR4, LM7, LQ4, L18 w/Denso)»(ref-277853-S02774687642008012100000) .
34. Disconnect the following electrical connectors: A/C pressure switch (4), if equipped A/C compressor clutch (1), if equipped
35. Remove the positive cable nut and cable from the generator.
36. Disconnect the following electrical connectors: Throttle position (TP) sensor (1) Idle air control (IAC) motor (2) Control port injector module (3) Engine coolant temperature (ECT) sensor (5)
37. Remove the engine wiring harness clip bolt (4).
38. Disconnect the following electrical connectors: Evaporative emission (EVAP) canister purge solenoid valve (1) Manifold absolute pressure (MAP) sensor (2)
39. Disconnect the following electrical connectors: Ignition coil (1) Ignition coil driver (2) Generator (3)
40. Remove the engine wiring harness ground nut and ground wire (4) from the rear of the right cylinder head.
41. Disconnect the following electrical connectors: Knock sensor (1) Camshaft position (CMP) sensor (2) Fuel pump/oil pressure sensor (3) Distributor (2)
42. Remove the harness ground bolt.
43. Reposition the harness ground (4) and ground strap (5).
44. Remove the engine wiring harness bracket nuts.
45. Remove the engine wiring harness bracket from the studs.
46. Remove the junction block bracket bolt.
47. Reposition the bracket and wiring harness aside.
48. Remove the engine wiring harness rear bracket nut at the EVAP canister purge solenoid valve.
49. Remove the stud holding the engine wiring harness bracket.
50. Reposition the engine wiring harness with the bracket aside.
51. Remove the heater hoses. Refer to «Heater Outlet Hose Replacement (4.3L)»(ref-277853-S16179397142008012100000) .
52. Remove the distributor cap. Refer to «Distributor Replacement»(ref-277873-S23388997282008012100000) .
53. Disconnect the EVAP canister harness from the purge solenoid valve.
54. Disconnect the power brake booster vacuum hose from the vacuum fitting.
55. Loosen the power steering (P/S) pump rear bracket nut.
56. Remove the P/S pump rear bracket front nut.
57. Remove the bolts and the nut for the P/S pump bracket.
58. Leave the A/C compressor, if equipped, and the P/S pump on the bracket.
59. Slide the P/S pump bracket forward off the stud and set aside.
60. Remove the thermostat and water outlet. Refer to «Thermostat Replacement (4.3L Engine)»(ref-277850-S16113110102008012100000) .
61. Remove the left front and right rear intake manifold lower bolts.
62. Install J 41427 to the left front and right rear intake manifold bolts, using the following procedure: Install the J 41427 marked RIGHT REAR. NOTE: Refer to «Fastener Notice»(ref-277849-S30907907212008012100000) . Install the lift bracket bolts. Tighten: Tighten the bolts to 15 N.m (11 lb ft). Install the J 41427 marked LEFT FRONT with the arrow pointing to the front of the engine. Install the lift bracket bolts. Tighten: Tighten the bolts to 15 N.m (11 lb ft).
63. Install a suitable lifting devise to the engine lift brackets.
64. Remove the engine mount to engine mount bracket nuts.
65. Support the transmission with a suitable floor jack.
66. Remove the engine.

1. Install the engine.
2. Install the engine mount to engine mount bracket bolts. Tighten: Tighten the bolts to 65 N.m (48 lb ft).
3. Remove the lifting devise and the J 41427 .
4. Apply threadlock to the threads of the intake manifold lower bolts.
5. Install the intake manifold bolts. Refer to «Sealers, Adhesives, and Lubricants»(ref-277938-S13821020292008012100000) for the correct part number. Tighten: Tighten the bolts a first pass to 3 N.m (27 lb in). Tighten the bolts a second pass to 12 N.m (106 lb in). Tighten the bolts a final pass to 15 N.m (11 lb ft).
6. Install one transmission bolt until snug.
7. Remove the support jack from under the transmission.
8. Install the thermostat and water outlet. Refer to «Thermostat Replacement (4.3L Engine)»(ref-277850-S16113110102008012100000) .
9. Slide the P/S pump bracket onto the stud.
10. Install the bolts and the nut for the P/S pump bracket.
11. Install the P/S pump rear bracket front nut.
12. Tighten the P/S pump rear bracket nut. Tighten: Tighten the bolts and nuts to 41 N.m (30 lb ft).
13. Connect the power brake booster vacuum hose to the vacuum fitting.
14. Connect the EVAP canister harness to the purge solenoid valve.
15. Install the distributor cap. Refer to «Distributor Replacement»(ref-277873-S23388997282008012100000) .
16. Install the heater hoses. Refer to «Heater Outlet Hose Replacement (4.3L)»(ref-277853-S16179397142008012100000) .
17. Position the engine wiring harness.
18. Install the stud holding the engine wiring harness bracket.
19. Install the engine wiring harness rear bracket nut at the EVAP canister purge solenoid valve. Tighten: Tighten the nut to 9 N.m (80 lb in).
20. Position the bracket and wiring harness.
21. Install the junction block bracket bolt. Tighten: Tighten the bolt to 25 N.m (18 lb ft).
22. Install the engine wiring harness bracket to the studs.
23. Install the engine wiring harness bracket nuts. Tighten: Tighten the nuts to 12 N.m (106 lb in).
24. Position the harness ground (4) and ground strap (5).
25. Install the harness ground bolt. Tighten: Tighten the bolt to 16 N.m (12 lb ft).
26. Connect the following electrical connectors: Knock sensor (1) CMP sensor (2) Fuel pump/oil pressure sensor (3) Distributor (2)
27. Install the engine wiring harness ground nut and ground wire (4) to the rear of the right cylinder head. Tighten: Tighten the nut to 16 N.m (12 lb ft).
28. Connect the following electrical connectors: Ignition coil (1) Ignition coil driver (2) Generator (3)
29. Connect the following electrical connectors: EVAP canister purge solenoid valve (1) MAP sensor (2)
30. Install the engine wiring harness clip bolt (4). Tighten: Tighten the bolt to 9 N.m (80 lb in).
31. Connect the following electrical connectors: TP sensor (1) IAC motor (2) Control port injector module (3) ECT sensor (5)
32. Install the positive cable and nut to the generator. Tighten: Tighten the nut to 18 N.m (13 lb ft).
33. Connect the following electrical connectors: A/C pressure switch (4), if equipped A/C compressor clutch (1), if equipped
34. If equipped, install the A/C hoses. Refer to «Discharge Hose Replacement (LB7)»(ref-277853-S28439312062008012100000) or «Discharge Hose Replacement (LR4, LM7, LQ4, L18)»(ref-277853-S31817298582008012100000) and «Suction Hose Replacement (LB7 w/Denso)»(ref-277853-S32123682532008012100000) or «Suction Hose Replacement (LR4, LM7, LQ4, L18 w/Denso)»(ref-277853-S02774687642008012100000) .
35. Position the bracket and cables.
36. Install the accelerator control cable bracket with the cables attached, to the throttle body.
37. Install the accelerator control cable bracket nuts. Tighten: Tighten the nuts to 9 N.m (80 lb in).
38. Install the accelerator cable to the throttle body lever.
39. Install the accelerator cable to the accelerator control cable bracket.
40. Install the accelerator cable to the throttle body lever.
41. If equipped, install the cruise control cable to the accelerator control cable bracket.
42. If equipped, connect the cruise control cable to the throttle body lever.
43. Install the radiator outlet hose to the water pump.
44. Install the radiator outlet hose to the surge tank.
45. Position the radiator outlet hose clamps.
46. Install the radiator inlet hose to the thermostat housing.
47. Position the radiator inlet hose clamp.
48. Install the drive belt. Refer to «Drive Belt Replacement»(ref-277938-S02095851762008012100000) .
49. Install the lower fan shroud. Refer to «Engine Coolant Fan Lower Shroud Replacement»(ref-277850-S42558773622008012100000) .
50. Install the fuel pipes/hoses. Refer to «Fuel Hose/Pipes Replacement - Engine Compartment»(ref-277873-S29478769382008012100000) .
51. Remove the hood hinge bolt from the service position (2).
52. Lower the hood to the normal position.
53. Install the hood hinge bolts. Tighten: Tighten the bolts to 25 N.m (18 lb ft).
54. Raise the vehicle.
55. Install the transmission bolts. Tighten: Tighten the bolts to 50 N.m (37 lb ft).
56. If equipped, install the torque converter bolts. Tighten: Tighten the bolts to 63 N.m (47 lb ft).
57. Install the ground bolt (3) holding the negative battery cable (6) and ground cable (4) to the engine.
58. Connect the CKP sensor electrical connector (5) and install the harness to the retainer clip.
59. Install the battery cable bracket bolts. Tighten: Tighten the bolts to 12 N.m (106 lb in).
60. Install the catalytic converter. Refer to «Catalytic Converter Replacement (4.3L, 4.8L, and 5.3L Engines)»(ref-277937-S01902361742008012100000) .
61. Install the positive battery cable clip bolt (2).
62. Install the transmission cover. Tighten: Tighten the bolts to 12 N.m (106 lb in).
63. Install the starter. Refer to «Starter Motor Replacement (4.3L Engine)»(ref-277854-S36909298662008012100000) .
64. If equipped, install the engine shield. Refer to «Engine Protection Shield Replacement»(ref-277879-S31943219262008012100000) .
65. If equipped, install the oil pan skid plate and bolts. Tighten: Tighten the bolts to 20 N.m (15 lb ft).
66. Lower the vehicle.
67. Connect the negative battery cable. Refer to «Battery Negative Cable Disconnection and Connection (Auxiliary Battery)»(ref-277854-S37314824542008012100000) or «Battery Negative Cable Disconnection and Connection (Single Battery)»(ref-277854-S29426527292008012100000) .
68. Perform the engine prelube procedure. Refer to «Engine Prelubing»(ref-277938-S11747732842008012100000) .
69. Add engine oil supplement to the engine oil. Refer to «Sealers, Adhesives, and Lubricants»(ref-277938-S13821020292008012100000) for the correct part number.
70. Fill the cooling system. Refer to «Draining and Filling Cooling System (Static Fill)»(ref-277850-S07555853772008012100000) or «Draining and Filling Cooling System (w/RPO HP2)»(ref-277850-S31192445052008012100000) or «Draining and Filling Cooling System (Vac-N-Fill)»(ref-277850-S00482587952008012100000) .
71. If equipped, bleed the hydraulic clutch. Refer to «Hydraulic Clutch Bleeding»(ref-277945-S27171015692008012100000) .
72. Recharge the A/C system. Refer to «Refrigerant Recovery and Recharging»(ref-277853-S11438759342008012100000) . IMPORTANT: After an overhaul, the engine should be tested. Use the following procedure after the engine is installed in the vehicle.
73. Disable the ignition system.
74. Crank the engine several times. Listen for any unusual noises or evidence that parts are binding.
75. Start the engine and listen for unusual noises.
76. Check the oil pressure gauge or light and confirm that the engine has acceptable oil pressure.
77. If necessary, install an oil pressure gage and measure the oil pressure.
78. Run the engine speed at about 1,000 RPM until the engine has reached normal operating temperature.
79. Listen for sticking valve lifters, or other unusual noises.
80. Inspect for fuel, oil, and/or coolant leaks while the engine is running.
81. Verify that the distributor is properly positioned.
82. Perform a final inspection for the proper oil and coolant levels.
83. Close the hood.

1. Raise and suitably support the vehicle. Refer to «Lifting and Jacking the Vehicle»(ref-277851-S21776392712008012100000) .
2. Remove the drain plug and drain the engine oil in a suitable container.
3. Remove the oil filter.
4. Inspect to ensure the engine oil filter gasket is removed.

1. Lubricate the oil filter gasket with clean engine oil.
2. Install the oil filter. Tighten: Tighten the filter to 30 N.m (22 lb ft).
3. Install the drain plug. Tighten: Tighten the plug to 25 N.m (18 lb ft).
4. Lower the vehicle.
5. Fill the engine with the proper capacity and quality of engine oil. Refer to «Approximate Fluid Capacities»(ref-277950-S03550976542008012100000) .
6. Operate the engine, check for leaks, and oil pressure.

Draining Fluids and Oil Filter Removal

1. Remove the oil pan drain plug and allow the engine oil to drain into a suitable container.
2. Remove the oil filter.
3. Discard the oil filter.
4. Remove both the engine block coolant drain hole plugs and allow the coolant to drain into a suitable container.

Engine Flywheel Removal

1. Remove the engine flywheel bolts.
2. Remove the engine flywheel (1), automatic transmission, if applicable.
3. Remove the engine flywheel (2), manual transmission, if applicable.
4. Note the position of any flywheel weights for assembly, if applicable.

Clutch Pilot Bearing Removal

1. Remove the clutch pilot bearing using the J 43276 . See «Special Tools»(ref-277938-S12463979202008012100000) . 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 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.

Exhaust Manifold Removal - Left Side

1. Remove the spark plug wires from the spark plugs. Rotate the spark plug wire boot one half turn. Pull outward on the spark plug wire boot to release from the spark plug.
2. Remove the spark plug wires from the spark plug wire retainers.
3. Remove the exhaust manifold bolts and the stud.
4. Remove the spark plug wire shields, if applicable, and the exhaust manifold.
5. Remove and discard the exhaust manifold gaskets.

Exhaust Manifold Removal - Right Side

1. Remove the spark plug wires from the spark plugs. Rotate the spark plug wire boot one half turn. Pull outward on the spark plug wire boot to release from the spark plug.
2. Remove the spark plug wires from the spark plug wire retainers.
3. Remove the exhaust manifold bolts.
4. Remove the spark plug wire shields and the exhaust manifold.
5. Remove and discard the exhaust manifold gaskets.

Oil Level Indicator and Tube Removal

1. Remove the oil level indicator from the oil level indicator tube, if required.
2. Remove the oil level indicator tube bolt.
3. Remove the oil level indicator tube from the engine block.

Water Pump Removal

1. Remove the bolts and the fan and water pump pulley using the J 41240 .
2. Remove the clamps and the water pump inlet hose.
3. Remove the water pump bolts.
4. Remove the water pump.
5. Remove the water pump gaskets.
6. Discard the water pump gaskets.

Crankshaft Balancer Removal

1. Remove the crankshaft balancer bolt and washer.
2. Remove the bolts and the crankshaft pulley.
3. Use the J 23523-F in order to remove the crankshaft balancer. Install the J 23523-F plate and bolts onto the crankshaft balancer. Tighten: Tighten the bolts to 25 N.m (18 lb ft). Install the J 23523-F forcing screw into the plate. Rotate the J 23523-F forcing screw clockwise in order to remove the crankshaft balancer.
4. Remove the J 23523-F from the crankshaft balancer.
5. Note the position and length of any crankshaft balancer front groove pins, if applicable.

Valve Rocker Arm Cover Removal - Left Side

1. Remove the valve rocker arm cover bolts.
2. Remove the valve rocker arm cover bolt grommets.
3. Discard the valve rocker arm cover bolt grommets.
4. Remove the valve rocker arm cover.
5. Remove the valve rocker arm cover gasket.
6. Discard the valve rocker arm cover gasket.

Valve Rocker Arm Cover Removal - Right Side

1. Remove the valve rocker arm cover bolts.
2. Remove the valve rocker arm cover bolt grommets.
3. Discard the valve rocker arm cover bolt grommets.
4. Remove the valve rocker arm cover.
5. Remove the valve rocker arm cover gasket.
6. Discard the valve rocker arm cover gasket.

Distributor Removal

1. Remove the ignition coil wire harness from the ignition coil and distributor cap.
2. Remove the distributor clamp bolt.
3. Remove the distributor and the distributor clamp.
4. Remove the distributor gasket and discard.

Intake Manifold Removal

1. Remove the evaporative emission (EVAP) canister purge solenoid valve harness. Push the quick disconnect clip and hold in place. Pull outward on the harness elbow.
2. Remove the engine coolant temperature (ECT) sensor wire connector, if equipped, from the engine wiring harness bracket.
3. Remove the lower intake manifold bolts.
4. Remove the intake manifold assembly.
5. Remove and discard the lower intake manifold gaskets.

Valve Rocker Arm and Push Rod Removal

1. Remove the valve rocker arms.
2. Remove the valve rocker arm supports.
3. Remove the valve pushrods.

Cylinder Head Removal - Left Side

1. Remove the engine coolant temperature sensor, if applicable.
2. Remove the engine coolant temperature gage sensor, if applicable.
3. Remove the spark plugs.
4. Remove the bolts and the spark plug wire support.
5. Remove the cylinder head bolts and discard.
6. Remove the cylinder head.
7. Remove and discard the cylinder head gasket.
8. Remove the cylinder head locator dowel pins, if required.

Cylinder Head Removal - Right Side

1. Remove the spark plugs.
2. Remove the rear bolt and the spark plug wire support.
3. Remove the cylinder head bolts and discard.
4. Remove the cylinder head.
5. Remove and discard the cylinder head gasket.
6. Remove the cylinder head locator dowel pins, if required.

Valve Lifter Removal

1. Remove the bolts and valve lifter pushrod guide.
2. Remove the valve lifters.
3. Use the J 3049-A in order to remove the stuck valve lifters. See «Special Tools»(ref-277938-S12463979202008012100000) .

Oil Pan Removal

1. Remove the oil pan bolts and nuts.
2. Remove the oil pan.
3. Remove the oil pan gasket.
4. Discard the oil pan gasket.

Oil Pump Removal

1. Remove the oil pump bolt.
2. Remove the oil pump.
3. Inspect the oil pump locator pins for damage, and replace the pins if required.

Engine Front Cover Removal

1. Remove the crankshaft position sensor bolt.
2. Remove the crankshaft position sensor.
3. Remove the crankshaft position sensor seal, O-ring.
4. Discard the crankshaft position sensor seal, O-ring.
5. Remove the engine front cover bolts.
6. Remove the engine front cover.
7. Discard the engine front cover.

Timing Chain and Sprockets Removal

1. Remove the crankshaft position sensor reluctor ring.
2. Remove the timing chain tensioner shoe (229) using a downward motion.
3. Remove the timing chain tensioner bracket bolt and bracket (227 and 228).
4. Check the camshaft timing chain free play. Rotate the camshaft sprocket (1) counterclockwise until all slack is removed from the camshaft timing chain (2). Measure the free play on the slack side (3) of the camshaft timing chain. If the camshaft timing chain can be moved side to side in excess of 11 mm (0.43 in), replacement of the camshaft timing chain and the sprockets is recommended during assembly.
5. Remove the camshaft sprocket bolts.
6. Remove the camshaft sprocket and the camshaft timing chain.
7. Remove the crankshaft sprocket using the J 5825-A . See «Special Tools»(ref-277938-S12463979202008012100000) .
8. Remove the crankshaft balancer key.

Balance Shaft Removal

1. Remove the balance shaft drive gear.
2. Remove the balance shaft driven gear bolt from the balance shaft. Use a wrench in order to secure the balance shaft. Place the wrench onto the balance shaft near to the balance shaft front bearing. Remove the balance shaft bolt. Remove the wrench from the balance shaft.
3. Remove the balance shaft driven gear from the balance shaft.
4. Remove the bolts and the balance shaft retainer.
5. Use a soft-faced hammer in order to remove the balance shaft from the engine block.

Camshaft Removal

1. Remove the camshaft retainer bolts and retainer.
2. Remove the engine camshaft. Install the three 5/16-18 x 4.0 inch bolts into the engine camshaft front bolt holes. Using the bolts as a handle, carefully rotate and pull the engine camshaft out of the camshaft bearings. Remove the bolts from the front of the engine camshaft.

Piston, Connecting Rod, and Bearing Removal

1. Use the J 24270 in order to remove the cylinder ring ridge. See «Special Tools»(ref-277938-S12463979202008012100000) . Turn the crankshaft until the piston is at the bottom of the stroke. Place a cloth on top of the piston. Use the J 24270 to remove all of the cylinder ring ridge. See «Special Tools»(ref-277938-S12463979202008012100000) . Turn the crankshaft so the piston is at the top of the stroke. Remove the cloth. Remove the cutting debris.
2. Remove the connecting rod bolts, cap, and bearing.
3. Remove the connecting rod and the piston out of the top of the engine block.
4. Remove the connecting rod bearings from the connecting rod. Keep all connecting rod bearings and rod bearing caps with the original connecting rods, and in the original orientation at the connecting rod/rod bearing cap mating area. Wipe the oil from the connecting rod bearings. Wipe the oil from the crankpins.

Crankshaft Rear Oil Seal and Housing Removal

1. Remove the crankshaft rear oil seal from the crankshaft rear oil seal housing. Insert a suitable tool into the access notches and then carefully pry the crankshaft rear oil seal from the crankshaft rear oil seal housing.
2. Discard the crankshaft rear oil seal.
3. Remove the crankshaft rear oil seal housing nut and bolts.
4. Remove the crankshaft rear oil seal housing.
5. Remove the crankshaft rear oil seal housing gasket.
6. Discard the crankshaft rear oil seal housing gasket.
7. Remove the crankshaft rear oil seal housing retainer stud from the engine block.

Crankshaft and Bearings Removal

1. Mark or identify the crankshaft bearing cap locations, direction, and positions for assembly.
2. Remove the crankshaft bearing cap bolts and discard.
3. Remove the crankshaft bearing caps.
4. Remove the crankshaft.
5. Remove the crankshaft bearings from the crankshaft bearing caps.
6. Remove the crankshaft bearings from the engine block.

Engine Block Plug Removal

1. Remove the knock sensor retaining bolt (1).
2. Remove the knock sensor (2).
3. Remove the engine oil pressure gage sensor using the J 41712 . See «Special Tools»(ref-277938-S12463979202008012100000) .
4. Remove the engine oil pressure sensor fitting.
5. Remove the transmission locator dowel straight pins, if required.
6. Remove the engine block left side oil gallery plug.
7. Remove the engine block left rear oil gallery plug.
8. Remove the engine block right rear oil gallery plug.
9. Remove the expansion cup plug from the camshaft rear bearing hole and discard.
10. Remove the expansion cup plug from the balance shaft rear bearing hole and discard.
11. Remove the crankshaft rear oil seal housing locator spring type S pin, if required.
12. Remove the front oil gallery plugs or balls from the front of the engine block and discard. Insert a 3/8 x 26 inch rod into the rear oil gallery holes in order to drive out the front oil gallery plugs or balls.
13. Remove the engine block core hole plugs. Use a suitable tool in order to drive the engine block core hole plugs into the coolant jacket. Use a suitable tool in order to pull the engine block core hole plugs from the coolant jacket. Discard the engine block core hole plugs.
14. Remove the oil filter bypass valve and discard.

Camshaft Bearing Removal

1. Select the cone (1), the handle (10), the expanding driver (4-8), the washer (2 or 3), and the expander assembly (15) from the J 33049 . See «Special Tools»(ref-277938-S12463979202008012100000) .
2. Assemble the J 33049 . See «Special Tools»(ref-277938-S12463979202008012100000) .
3. Remove the camshaft inner bearings #2 and #3. Insert the J 33049 through the front of the engine block and into the camshaft inner bearing #2. See «Special Tools»(ref-277938-S12463979202008012100000) . Tighten the J 33049 expander assembly nut until snug. See «Special Tools»(ref-277938-S12463979202008012100000) . Push the J 33049 guide cone into the camshaft front bearing in order to align the J 33049 . See «Special Tools»(ref-277938-S12463979202008012100000) . Drive the camshaft inner bearing #2 from the camshaft inner bearing bore #2. Loosen the J 33049 expander assembly nut. See «Special Tools»(ref-277938-S12463979202008012100000) . Remove the camshaft inner bearing #2 from the J 33049 expander assembly. See «Special Tools»(ref-277938-S12463979202008012100000) . Insert the J 33049 expander assembly into the camshaft inner bearing #3. See «Special Tools»(ref-277938-S12463979202008012100000) . Tighten the J 33049 expander assembly nut until snug. See «Special Tools»(ref-277938-S12463979202008012100000) . Push the J 33049 guide cone into the camshaft front bearing in order to align the J 33049 . See «Special Tools»(ref-277938-S12463979202008012100000) . Drive the camshaft inner bearing #3 from the camshaft inner bearing bore #3. Loosen the J 33049 expander assembly nut. See «Special Tools»(ref-277938-S12463979202008012100000) . Remove the camshaft inner bearing #3 from the J 33049 expander assembly. See «Special Tools»(ref-277938-S12463979202008012100000) .
4. Remove the J 33049 from the engine block. See «Special Tools»(ref-277938-S12463979202008012100000) .
5. Remove the camshaft outer bearings #1 and #4. Insert the J 33049 into the camshaft outer bearing #1. See «Special Tools»(ref-277938-S12463979202008012100000) . Tighten the J 33049 expander assembly nut until snug. See «Special Tools»(ref-277938-S12463979202008012100000) . Drive the camshaft outer bearing #1 from the camshaft outer bearing bore #1. Loosen the J 33049 expander assembly nut. See «Special Tools»(ref-277938-S12463979202008012100000) . Remove the camshaft outer bearing #1 from the J 33049 expander assembly. See «Special Tools»(ref-277938-S12463979202008012100000) . Remove the J 33049 from the engine block. See «Special Tools»(ref-277938-S12463979202008012100000) . Insert the J 33049 into the camshaft outer bearing #4. See «Special Tools»(ref-277938-S12463979202008012100000) . Tighten the J 33049 expander assembly nut until snug. See «Special Tools»(ref-277938-S12463979202008012100000) . Drive the camshaft outer bearing #4 from the camshaft outer bearing bore #4. Loosen the J 33049 expander assembly nut. See «Special Tools»(ref-277938-S12463979202008012100000) . Remove the camshaft outer bearing #4 from the J 33049 expander assembly. See «Special Tools»(ref-277938-S12463979202008012100000) .
6. Remove the J 33049 from the engine block. See «Special Tools»(ref-277938-S12463979202008012100000) .
7. Discard the camshaft bearings.

Scheme 2

1. Assemble the J 33049 handle (10), the expanding driver (4-8), the washer (2 or 3), and the expander assembly (15). See «Special Tools»(ref-277938-S12463979202008012100000) .
2. Install the NEW camshaft outer bearings #4 and #1. Install the NEW camshaft outer bearing #4 onto the J 33049 expander assembly. See «Special Tools»(ref-277938-S12463979202008012100000) . Tighten the J 33049 expander assembly nut until snug. See «Special Tools»(ref-277938-S12463979202008012100000) . Align the lubrication hole of the camshaft outer bearing #4 above the 3 o'clock position or the 9 o'clock position of the camshaft outer bearing bore #4 at the rear of the engine block. Drive the camshaft outer bearing #4 into the camshaft outer bearing bore #4 at the rear of the engine block. Loosen the J 33049 expander assembly nut. See «Special Tools»(ref-277938-S12463979202008012100000) . Remove the camshaft outer bearing #4 from the J 33049 expander assembly. See «Special Tools»(ref-277938-S12463979202008012100000) . Install the NEW camshaft outer bearing #1 onto the J 33049 expander assembly. See «Special Tools»(ref-277938-S12463979202008012100000) . Tighten the J 33049 expander assembly nut until snug. See «Special Tools»(ref-277938-S12463979202008012100000) . Align the lubrication hole of the camshaft outer bearing #1 above the 3 o'clock position or the 9 o'clock position of the camshaft outer bearing bore #1 at the front of the engine block. Drive the camshaft outer bearing #1 into the camshaft outer bearing bore #1 at the front of the engine block. Loosen the J 33049 expander assembly nut. See «Special Tools»(ref-277938-S12463979202008012100000) . Carefully slide the J 33049 into the engine block until the J 33049 expander assembly is positioned between the camshaft inner bearing bores. See «Special Tools»(ref-277938-S12463979202008012100000) .
3. Install the NEW camshaft inner bearings #3 and #2. Install the NEW camshaft inner bearing #3 onto the J 33049 expander assembly. See «Special Tools»(ref-277938-S12463979202008012100000) . Tighten the J 33049 expander assembly nut until snug. See «Special Tools»(ref-277938-S12463979202008012100000) . Align the lubrication hole of the camshaft inner bearing #3 above the 3 o'clock position or the 9 o'clock position of the camshaft inner bearing bore #3 of the engine block. Push the J 33049 guide cone into the camshaft front bearing bore #1 in order to align the J 33049 . See «Special Tools»(ref-277938-S12463979202008012100000) . Drive the camshaft inner bearing #3 into the camshaft inner bearing bore #3. Loosen the J 33049 expander assembly nut. See «Special Tools»(ref-277938-S12463979202008012100000) . Carefully slide the J 33049 until the J 33049 expander assembly is positioned between the camshaft inner bearing bore #2 and the camshaft outer bearing bore #1. See «Special Tools»(ref-277938-S12463979202008012100000) . Install the NEW camshaft inner bearing #2 onto the J 33049 expander assembly. See «Special Tools»(ref-277938-S12463979202008012100000) . Tighten the J 33049 expander assembly nut until snug. See «Special Tools»(ref-277938-S12463979202008012100000) . Align the lubrication hole of the camshaft inner bearing #2 above the 3 o'clock position or the 9 o'clock position of the camshaft inner bearing bore #2 of the engine block. Push the J 33049 guide cone into the camshaft front bearing bore #1 in order to align the J 33049 . See «Special Tools»(ref-277938-S12463979202008012100000) . Drive the camshaft inner bearing #2 into the camshaft inner bearing bore #2. Loosen the J 33049 expander assembly nut. See «Special Tools»(ref-277938-S12463979202008012100000) .
4. Carefully remove the J 33049 from the engine block. See «Special Tools»(ref-277938-S12463979202008012100000) .

Balance Shaft Bearing and/or Bushing Removal

Tools Required

1. J 26941 Bushing/Bearing Remover. See «Special Tools»(ref-277938-S12463979202008012100000) .
2. J 38834 Balance Shaft Service Kit. See «Special Tools»(ref-277938-S12463979202008012100000) .

1. Use the J 38834 and the J 26941 in order to remove the balance shaft rear bearing. See «Special Tools»(ref-277938-S12463979202008012100000) . Install J 26941 legs behind the balance shaft rear bearing and secure. See «Special Tools»(ref-277938-S12463979202008012100000) . Install the J 38834-1 with the short threaded end through the balance shaft bore in the front of the engine block. Install the J 38834-1 into J 26941 . See «Special Tools»(ref-277938-S12463979202008012100000) . Slide the J 38834-2 onto the J 38834-1 and into the balance shaft bore of the engine block. Install the J 38834 bearing, washer, and nut onto the J 38834-1. See «Special Tools»(ref-277938-S12463979202008012100000) . Using a wrench secure the J 38834-1 and then rotate the J 38834 nut clockwise until the balance shaft rear bearing is removed from the engine block. See «Special Tools»(ref-277938-S12463979202008012100000) . Remove the J 26941 from the balance shaft rear bearing. See «Special Tools»(ref-277938-S12463979202008012100000) .
2. Discard the balance shaft rear bearing.

Balance Shaft Bearing and/or Bushing Installation

1. Use the J 38834 in order to install the balance shaft rear bearing. See «Special Tools»(ref-277938-S12463979202008012100000) . Install the J 38834-3 onto the short threaded end of the J 38834-1. Install the J 38834 nut, the washer, and the bearing on the long threaded end of the J 38834-1. See «Special Tools»(ref-277938-S12463979202008012100000) . Install the J 38834-2 onto the J 38834-1 so that the smaller diameter of the J 38834-2 will be facing the front of the engine block. Install the J 38834-2 on the inside of the balance shaft front bearing bore. Lubricate the NEW balance shaft rear bearing with clean engine oil. Install the balance shaft rear bearing onto the J 38834-2. Align the balance shaft rear bearing for installation. Using a wrench secure the J 38834-1 into place. Rotate the J 38834 nut until the balance shaft rear bearing is properly and completely pushed into the balance shaft rear bearing bore. See «Special Tools»(ref-277938-S12463979202008012100000) .
2. Remove the J 38834 . See «Special Tools»(ref-277938-S12463979202008012100000) .

Engine Block Plug Installation

1. Install a NEW oil filter bypass valve. Install the oil filter bypass valve into the oil gallery bore until slightly below flush with the surface of the engine block. Using a pointed punch, stake the engine block area around the oil filter bypass valve. Stake in 3 locations 120 degrees apart.
2. Apply sealant GM P/N 12346004 (Canadian P/N 10953480) or equivalent, to the outside diameter of the NEW front engine oil gallery plugs.
3. Install the NEW front engine block oil gallery plugs. A properly installed front engine oil gallery plug must be installed slightly below flush with the front face of the engine block.
4. Apply threadlock GM P/N 12345382 (Canadian P/N 10953489) or equivalent, to the outside diameter of the NEW engine block core hole plugs.
5. Install the NEW engine block core hole plugs. A properly installed engine block core hole plug must be installed flush or below the bottom of the chamfer (1) of the engine block core hole.
6. Install the crankshaft rear oil seal housing locator spring type S pin, if required.
7. Apply sealant GM P/N 12346004 (Canadian P/N 10953480) or equivalent, to the outside diameter of the NEW expansion cup plug.
8. Install the NEW expansion cup plug into the balance shaft rear bearing hole.
9. Apply sealant GM P/N 12346004 (Canadian P/N 10953480) or equivalent, to the outside diameter of the NEW expansion cup plug.
10. Install the NEW expansion cup plug into the camshaft rear bearing hole.
11. Apply sealant GM P/N 12346004 (Canadian P/N 10953480) or equivalent, to the threads of the engine block right rear oil gallery plug, the engine block left rear oil gallery plug, and the engine block left side oil gallery plug.
12. Install the engine block right rear oil gallery plug, the engine block left rear oil gallery plug, and the engine block left side oil gallery plug. Tighten: Tighten the engine block left side oil gallery plug and the engine block right rear oil gallery plug to 20 N.m (15 lb ft). Tighten the engine block left rear oil gallery plug to 30 N.m (22 lb ft).
13. Install the transmission locator dowel straight pins, if required.
14. Install the left side cylinder head locator dowel pins, if required. The installation height should be 6.3-6.5 mm (0.248-0.256 in) (a).
15. Install the right side cylinder head locator dowel pins, if required. The installation height should be 6.3-6.5 mm (0.248-0.256 in) (a).
16. Apply sealant GM P/N 12346004 (Canadian P/N 10953480) or equivalent, to the threads of the engine block coolant drain hole plugs.
17. Install the engine block coolant drain hole plugs. Tighten: Tighten the engine block coolant hole plugs to 20 N.m (15 lb ft).
18. If reusing the engine oil pressure sensor fitting, apply sealant GM P/N 12346004 (Canadian P/N 10953480) or equivalent, to the threads of the engine oil pressure sensor fitting.
19. Install the engine oil pressure sensor fitting. Tighten: Tighten the engine oil pressure sensor fitting to 15 N.m (11 lb ft).
20. Rotate the engine oil pressure sensor fitting clockwise to the proper position (1), 50 degrees from the centerline (2).
21. If reusing the engine oil pressure gage sensor, apply sealant GM P/N 12346004 (Canadian P/N 10953480) or equivalent, to the threads of the engine oil pressure gage sensor.
22. Install the engine oil pressure gage sensor using the J 41712 . See «Special Tools»(ref-277938-S12463979202008012100000) . Tighten: Tighten the engine oil pressure gage sensor to 30 N.m (22 lb ft).
23. Install the knock sensor (2).
24. Install the knock sensor retaining bolt (1). Tighten: Tighten the knock sensor to 25 N.m (18 lb ft).

Crankshaft and Bearings Installation

1. Install the crankshaft bearings into the engine block.
2. Apply clean engine oil to the crankshaft bearings.
3. Apply clean engine oil to the crankshaft bearing journals.
4. Install the crankshaft.
5. Install the crankshaft bearings into the crankshaft bearing caps.
6. Apply clean engine oil to the crankshaft bearings.
7. Install the crankshaft bearing caps in the original position and with the arrow on the crankshaft bearing caps in the direction of the front of the engine block.
8. Install the NEW crankshaft bearing cap bolts until snug.
9. Thrust the crankshaft rearward in order to set and align the crankshaft thrust bearings and the crankshaft bearing caps.
10. Thrust the crankshaft forward in order to align the rear faces of the crankshaft thrust bearings.
11. Tighten the crankshaft bearing cap bolts. Tighten: Tighten the crankshaft bearing cap bolts on the first pass to 20 N.m (15 lb ft). Tighten the crankshaft bearing cap bolts on the final pass an additional 73 degrees using the J 45059 . See «Special Tools»(ref-277938-S12463979202008012100000) .
12. Measure the crankshaft end play. Firmly thrust the crankshaft rearward, and then forward. This will align the crankshaft rear bearing thrust surfaces. With the crankshaft pushed forward, insert a feeler gage between the crankshaft and the crankshaft rear bearing thrust surface to measure the clearance. Specification: Crankshaft end play 0.05-0.20 mm (0.002-0.008 in)
13. Rotate the crankshaft in order to check for binding. A bent crankshaft or lack of proper crankshaft bearing clearance may cause binding.
14. If the crankshaft does not turn freely, loosen the crankshaft bearing cap bolts on 1 crankshaft bearing cap at a time in order to determine the location of the binding. A lack of proper crankshaft bearing clearance may be caused by the following: Burrs on the crankshaft bearing cap Foreign material between the crankshaft bearing and the engine block Foreign material between the crankshaft bearing and the crankshaft bearing cap Damaged crankshaft bearing Improper size crankshaft bearing

Crankshaft Rear Oil Seal and Housing Installation

1. Install the crankshaft rear oil seal housing retainer stud. Tighten: Tighten the crankshaft rear oil seal housing retainer stud to 6 N.m (53 lb in).
2. Install the NEW crankshaft rear oil seal housing gasket.
3. Install the crankshaft rear oil housing onto the crankshaft rear oil seal housing retainer stud.
4. Install the crankshaft rear oil seal housing nut and bolts. Tighten: Tighten the crankshaft rear oil seal housing nut and bolts to 12 N.m (106 lb in).
5. Inspect the J 35621-B flange for imperfections that may damage the crankshaft rear oil seal. See «Special Tools»(ref-277938-S12463979202008012100000) . Minor imperfections may be removed with a fine grade emery cloth.
6. Clean the crankshaft sealing surface with a clean, lint free towel. Inspect the lead-in edge of the crankshaft for burrs or sharp edges that could damage the rear main oil seal. Remove the burrs or sharp edges with a fine grade emery cloth before proceeding.
7. Carefully remove the protection sleeve from the NEW crankshaft rear oil seal.
8. Install the crankshaft rear oil seal onto the J 35621-B . See «Special Tools»(ref-277938-S12463979202008012100000) .
9. Install the J 35621-B onto the rear of the crankshaft and hand tighten the tool bolts until snug. See «Special Tools»(ref-277938-S12463979202008012100000) .
10. Install the crankshaft rear oil seal onto the crankshaft and into the crankshaft rear oil seal housing. Turn the J 35621-B wing nut clockwise until the crankshaft rear oil seal is installed near to flush and square to the crankshaft rear oil seal housing. See «Special Tools»(ref-277938-S12463979202008012100000) . Increased resistance will be felt when the crankshaft rear oil seal has reached the bottom of the crankshaft rear oil seal housing bore. Turn the J 35621-B wing nut counterclockwise to release the J 35621-B from the crankshaft rear oil seal. See «Special Tools»(ref-277938-S12463979202008012100000) .
11. Remove the J 35621-B from the crankshaft. See «Special Tools»(ref-277938-S12463979202008012100000) .
12. Wipe off any excess engine oil with a clean rag.

Piston, Connecting Rod, and Bearing Installation

Tools Required

1. J 8037 Ring Compressor. See «Special Tools»(ref-277938-S12463979202008012100000) .
2. J 8087 Cylinder Bore Gage
3. J 45059 Angle Meter. See «Special Tools»(ref-277938-S12463979202008012100000) .

1. Apply clean engine oil to the following components: The piston The piston rings The cylinder bore The bearing surfaces
2. Install the J 8037 onto the piston and compress the piston rings. See «Special Tools»(ref-277938-S12463979202008012100000) .
3. Check reference marks prior to installation into the block.
4. Install the piston and connecting rod assembly, and the J 8037 into the proper cylinder bore. See «Special Tools»(ref-277938-S12463979202008012100000) .
5. Use the J 8037 and lightly tap the top of the piston with a wooden hammer handle. See «Special Tools»(ref-277938-S12463979202008012100000) . Hold the J 8037 firmly against the engine block until all of the piston rings have entered the cylinder bore. See «Special Tools»(ref-277938-S12463979202008012100000) .
6. Install the connecting rod bearing, cap, and bolts. Tighten: Tighten the bolts evenly on the first pass to 20 N.m (15 lb ft). Use the J 45059 in order to tighten the bolts on the final pass an additional 100 degrees. See «Special Tools»(ref-277938-S12463979202008012100000) .
7. 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.
8. 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).

Camshaft Installation

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.
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: Tighten the camshaft retainer bolts to 12 N.m (106 lb in).

Balance Shaft Installation

Tools Required

1. J 8092 Universal Driver Handle
2. J 36996 Balance Shaft Installer. See «Special Tools»(ref-277938-S12463979202008012100000) .
3. J 45059 Angle Meter. See «Special Tools»(ref-277938-S12463979202008012100000) .

1. Apply clean engine oil GM P/N 12345610 (Canadian P/N 993193) or equivalent, to the balance shaft front bearing.
2. Use the J 36996 and the J 8092 in order to install the balance shaft. See «Special Tools»(ref-277938-S12463979202008012100000) .
3. Install the balance shaft retainer and bolts. Tighten: Tighten the bolts to 12 N.m (106 lb in).
4. Install the balance shaft driven gear onto the balance shaft.
5. If reusing the fastener, apply threadlock GM P/N 12345382 (Canadian P/N 10953489) or equivalent, to the threads of the balance shaft driven gear bolt.
6. Install the balance shaft driven gear bolt. Use a wrench to secure the balance shaft. Place the wrench onto the balance shaft near to the balance shaft front bearing. Install the balance shaft driven gear bolt. Tighten: Tighten the balance shaft driven gear bolt on the first pass to 20 N.m (15 lb ft). Tighten the balance shaft driven gear bolt on the final pass using the J 45059 an additional 35 degrees. See «Special Tools»(ref-277938-S12463979202008012100000) .
7. Remove the wrench from the balance shaft.
8. Rotate the balance shaft by hand in order to ensure that there is clearance between the balance shaft and the valve lifter pushrod guide. If the balance shaft does not rotate freely, check to ensure that the retaining ring on the balance shaft front bearing is seated on the case.
9. Install the balance shaft drive gear.
10. Rotate the engine camshaft so that the timing mark on the balance shaft drive gear is in the 12 o'clock position.
11. Remove the balance shaft drive gear.
12. Rotate the balance shaft so that the timing mark on the balance shaft driven gear is in the 6 o'clock position.
13. Position the balance shaft drive gear onto the engine camshaft.
14. Look to ensure that the balance shaft drive gear and the balance shaft driven gear timing marks are aligned.

Timing Chain and Sprockets Installation

1. Install the crankshaft balancer key into the crankshaft keyway. The crankshaft balancer key should be parallel to the crankshaft or with a slight incline.
2. Align the keyway of the crankshaft sprocket with the crankshaft balancer key.
3. Use the J 5590 in order to install the crankshaft sprocket. See «Special Tools»(ref-277938-S12463979202008012100000) .
4. Rotate the crankshaft until the crankshaft sprocket alignment mark is at the 12 o'clock position.
5. Install the camshaft sprocket and the camshaft timing chain.
6. Look to ensure that the crankshaft sprocket is aligned at the 12 o'clock position and camshaft sprocket is aligned at the 6 o'clock position.
7. Install camshaft sprocket bolts. Tighten: Tighten the camshaft sprocket bolts to 25 N.m (18 lb ft).
8. Install the timing chain tensioner bracket and bolt (227 and 228). Tighten: Tighten the timing chain tensioner bracket bolt to 12 N.m (106 lb in).
9. Install the timing chain tensioner shoe (229) using an upwards motion.
10. Install the crankshaft position sensor reluctor ring. Align the keyway on the crankshaft position sensor reluctor ring with the crankshaft balancer key in the crankshaft. Use the J 5590 in order to push the crankshaft position sensor reluctor ring onto the crankshaft until completely seated against the crankshaft sprocket. See «Special Tools»(ref-277938-S12463979202008012100000) .

Engine Front Cover Installation

1. Install the NEW engine front cover.
2. Install the engine front cover bolts. Tighten: Tighten the bolts to 12 N.m (106 lb in).
3. Lubricate the NEW crankshaft position sensor seal, O-ring, with clean engine oil.
4. Install the NEW crankshaft position sensor seal, O-ring, onto the crankshaft position sensor.
5. Install crankshaft position sensor until fully seated into the engine front cover.
6. Install crankshaft position sensor bolt. Tighten: Tighten the crankshaft position sensor bolt to 8 N.m (71 lb in).

Oil Pump Installation

1. Inspect for properly installed oil pump locator pins.
2. Install the oil pump.
3. Position the oil pump onto the pins.
4. Install the oil pump bolt attaching the oil pump to the rear crankshaft bearing cap. Tighten: Tighten the oil pump bolt to 90 N.m (66 lb ft).

Oil Pan Installation

1. Apply a 5 mm (0.197 in) wide and 25 mm (1.0 in) long bead of adhesive GM P/N 12346141 (Canadian P/N 10953433) or equivalent, to both the right and left sides of the engine front cover to engine block junction at the oil pan sealing surfaces.
2. Apply a 5 mm (0.197 in) wide and 25 mm (1.0 in) long bead of adhesive GM P/N 12346141 (Canadian P/N 10953433) or equivalent, to the entire crankshaft rear oil seal housing to engine block junction at the oil pan sealing surfaces.
3. Install the NEW oil pan gasket into the groove in the oil pan.
4. Install the oil pan onto the engine block. Press the oil pan gasket into the grooves of the engine front cover and crankshaft rear oil seal housing.
5. Slide the oil pan back against a suitable straight edge.
6. Install the oil pan bolts and nuts, but do not tighten.
7. Measure the pan-to-transmission housing clearance using a feeler gage and a straight edge. Use a feeler gage to check the clearance between the oil pan-to-transmission housing measurement points. If the clearance exceeds 0.3 mm (0.011 in) at any of the 3 oil pan-to-transmission housing measurement points (1), then repeat the step until the oil pan-to-transmission housing clearance is within the specification. The oil pan must always be forward of the rear face of the engine block.
8. Tighten the oil pan bolts and nuts in sequence (1-12). Tighten: Tighten the oil pan bolts to 25 N.m (18 lb ft).
9. Measure the clearance between the 3 oil pan-to-transmission housing measurement points in order to ensure proper alignment.
10. Install a NEW oil pan drain plug seal, O-ring, onto the oil pan drain plug.
11. Install the oil pan drain plug into the oil pan. Tighten: Tighten the oil pan drain plug to 25 N.m (18 lb ft).

Crankshaft Balancer Installation

1. Look to ensure that the crankshaft balancer front groove pin is installed in the proper location, if applicable. The length and location of the pins must be the same as the original length and location.
2. Apply a small amount of adhesive GM P/N 12346141 (Canadian P/N 10953433) or equivalent, onto the crankshaft balancer keyway in order to seal the crankshaft balancer keyway and crankshaft joint.
3. Align the keyway of the crankshaft balancer with the crankshaft balancer key.
4. Install the crankshaft balancer onto the end of the crankshaft.
5. Use the J 23523-F in order to press the crankshaft balancer onto the crankshaft. Install the J 23523-F plate and bolts onto the front of the crankshaft balancer. Tighten: Tighten the J 23523-F plate bolts to 25 N.m (18 lb ft). Install the J 23523-F screw into the end for the crankshaft. Install the J 23523-F bearing, the washer, and the nut onto the J 23523-F screw. Rotate the J 23523-F nut clockwise until the crankshaft balancer hub is completely seated against the crankshaft position sensor reluctor ring.
6. Remove the J 23523-F .
7. Install the crankshaft pulley and bolts. Finger tighten all bolts until snug. Tighten: Tighten the crankshaft pulley bolts to 58 N.m (43 lb ft).
8. Ensure that the crown of the crankshaft balancer washer (2) is faced away from the engine.
9. Install the crankshaft balancer washer and the bolt. Tighten: Tighten the crankshaft balancer bolt to 95 N.m (70 lb ft).

Valve Lifter Installation

1. Apply lubricant GM P/N 12345501 (Canadian P/N 992704) or equivalent, to the valve lifter rollers.
2. Install the valve lifters.
3. Install the valve lifter pushrod guides. Tighten: Tighten the valve lifter pushrod guide bolts to 16 N.m (12 lb ft).

Cylinder Head Installation - Left Side

1. Clean the cylinder head gasket surfaces on the engine block.
2. Inspect the cylinder head locator dowel pins for proper installation. The installation height should be 6.3-6.5 mm (0.248-0.256 in) (a).
3. Clean the cylinder head gasket surfaces on the cylinder head.
4. Install the NEW cylinder head gasket in position over the cylinder head locator dowel pins.
5. Install the cylinder head onto the engine block. Guide the cylinder head carefully into place over the dowel pins and the cylinder head gasket.
6. Apply sealant GM P/N 12346004 (Canadian P/N 10953480) or equivalent, to the threads of the NEW cylinder head bolts.
7. Install the NEW cylinder head bolts finger tight.
8. Tighten the cylinder head bolts in sequence on the first pass. Tighten: Tighten the bolts in sequence on the first pass to 30 N.m (22 lb ft).
9. Use the J 45059 in order to tighten the cylinder head bolts in sequence on the final pass. See «Special Tools»(ref-277938-S12463979202008012100000) . Tighten: Tighten the long bolts (1, 4, 5, 8, and 9) on the final pass in sequence to 75 degrees. Tighten the medium bolts (12 and 13) on the final pass in sequence to 65 degrees. Tighten the short bolts (2, 3, 6, 7, 10, and 11) on the final pass in sequence to 55 degrees.
10. Install the spark plug wire support and bolts. Tighten: Tighten the spark plug wire support bolts to 12 N.m (106 lb in).
11. Measure the spark plugs for the proper gap. Adjust the spark plug gap if necessary. Specification: Spark plug gap to 1.52 mm (0.060 in).
12. Install the spark plugs. Tighten: Tighten the spark plugs to 15 N.m (11 lb ft).
13. If reusing the engine coolant temperature gage sensor, if applicable, apply sealant GM P/N 12346004 (Canadian P/N 10953480) or equivalent, to the threads of the engine coolant temperature gage sensor.
14. Install the engine coolant temperature gage sensor, if applicable. Tighten: Tighten the engine coolant temperature gage sensor to 20 N.m (15 lb ft).
15. If reusing the engine coolant temperature sensor, if applicable, apply sealant GM P/N 12346004 (Canadian P/N 10953480) or equivalent, to the threads of the engine coolant temperature gage sensor.
16. Install the engine coolant temperature sensor, if applicable. Tighten: Tighten the engine coolant temperature sensor to 20 N.m (15 lb ft).

Cylinder Head Installation - Right Side

1. Clean the cylinder head gasket surfaces on the engine block.
2. Inspect the cylinder head locator dowel pins for proper installation. The installation height should be 6.3-6.5 mm (0.248-0.256 in) (a).
3. Clean the cylinder head gasket surfaces on the cylinder head.
4. Install the NEW cylinder head gasket in position over the cylinder head locator dowel pins.
5. Install the cylinder head onto the engine block. Guide the cylinder head carefully into place over the dowel pins and the cylinder head gasket.
6. Apply sealant GM P/N 12346004 (Canadian P/N 10953480) or equivalent, to the threads of the NEW cylinder head bolts.
7. Install the NEW cylinder head bolts finger tight.
8. Tighten the cylinder head bolts in sequence on the first pass. Tighten: Tighten the bolts in sequence on the first pass to 30 N.m (22 lb ft).
9. Use the J 45059 in order to tighten the cylinder head bolts in sequence on the final pass. See «Special Tools»(ref-277938-S12463979202008012100000) . Tighten: Tighten the long bolts (1, 4, 5, 8, and 9) on the final pass in sequence to 75 degrees. Tighten the medium bolts (12 and 13) on the final pass in sequence to 65 degrees. Tighten the short bolts (2, 3, 6, 7, 10, and 11) on the final pass in sequence to 55 degrees.
10. Install the spark plug wire support and bolts. Tighten: Tighten only the rear spark plug wire support bolt to 12 N.m (106 lb in).
11. Remove the front spark plug wire support bolt. The front spark plug wire support bolt is used to fasten the oil level indicator tube, and will be installed within the oil level indicator tube installation procedure.
12. Measure the spark plugs for the proper gap. Adjust the spark plug gap if necessary. Specification: Spark plug gap to 1.52 mm (0.060 in).
13. Install the spark plugs. Tighten: Tighten the spark plugs to 15 N.m (11 lb ft).

Valve Rocker Arm and Push Rod Installation

1. Install the valve pushrods.
2. Install the valve rocker arm supports.
3. Apply prelube GM P/N 12345501 (Canadian P/N 992704) or equivalent, to the following valve rocker arm contact surfaces: Valve pushrod socket (1) Roller pivot (2) Valve stem tip (3)
4. Install the valve rocker arm assemblies as follows: Finger start the bolt at location (1) Finger start the bolt at location (2) Finger start the bolt at location (3) Finger start the remaining valve rocker arm bolts
5. Rotate the crankshaft balancer clockwise until the alignment marks on the crankshaft balancer are aligned with the tabs on the engine front cover, 1 with 2 and 3 with 4. At that point the number 1 piston should be at TDC of the compression stroke.
6. Tighten the valve rocker arm bolts. Tighten: Tighten valve rocker arm bolts to 30 N.m (22 lb ft).

Intake Manifold Installation

1. Apply a 4.0 mm (0.157 in) patch of adhesive GM P/N 12346141 (Canadian P/N 10953433) or equivalent, to the cylinder head side of the lower intake manifold gasket at each end.
2. Install the lower intake manifold gasket onto the cylinder head. Use the gasket locator pins in order to properly seat the lower intake manifold gasket on the cylinder head.
3. Apply a 5 mm (0.197 in) bead of adhesive GM P/N 12346141 (Canadian P/N 10953433) or equivalent, to the front top of the engine block.
4. Extend the adhesive bead 13 mm (0.50 in) onto each lower intake manifold gasket.
5. Apply a 5 mm (0.197 in) bead of adhesive GM P/N 12346141 (Canadian P/N 10953433) or equivalent, to the rear top of the engine block.
6. Extend the adhesive bead 13 mm (0.50 in) onto each lower intake manifold gasket.
7. Install the lower intake manifold onto the engine block.
8. If reusing the fasteners, apply threadlock GM P/N 12345382 (Canadian P/N 10953489) or equivalent, to the threads of the lower intake manifold bolts.
9. Install the lower intake manifold bolts.
10. Tighten the lower intake manifold bolts. Tighten: Tighten the bolts on the first pass in sequence (1-8) to 3 N.m (27 lb in). Tighten the bolts on the second pass in sequence (1-8) to 12 N.m (106 lb in). Tighten the bolts on the final pass in sequence (1-8) to 15 N.m (11 lb ft).
11. Connect the evaporative emission (EVAP) canister solenoid valve harness. Push the elbow inward until the quick connect snaps into place. Pull the elbow outward in order to ensure proper connection.

Distributor Installation

1. Rotate the crankshaft balancer clockwise until the alignment marks on the crankshaft balancer are aligned with the tabs on the engine front cover and the number 1 piston is at top dead center of the compression stroke.
2. Remove the distributor cap bolts and discard.
3. Remove the distributor cap.
4. Install a NEW distributor gasket onto the distributor.
5. Align the indent hole on the driven gear with the paint mark on the distributor housing.
6. Ensure that the distributor rotor segment points to the cap hold area.
7. Align the slotted tang in the oil pump driveshaft with the distributor driveshaft. Rotate the oil pump driveshaft with a screwdriver if necessary.
8. Align the flat (1) in the distributor housing toward the front of the engine.
9. Install the distributor and distributor clamp. The flat in the distributor housing must point toward the front of the engine.
10. Once the distributor is fully seated, align the distributor rotor segment with the number 6 pointer (1) that is cast into the distributor base. If the distributor rotor segment does not come within a few degrees of the number 6 pointer (1), the gear mesh between the distributor and camshaft may be off a tooth or more. Repeat the procedure again in order to achieve proper alignment.
11. Install the distributor clamp bolt. Tighten: Tighten the distributor clamp bolt to 25 N.m (18 lb ft).
12. Install the distributor cap and NEW distributor cap bolts. Tighten: Tighten the distributor cap bolts to 2.4 N.m (21 lb in).
13. Install the ignition coil wire harness.

Valve Rocker Arm Cover Installation - Left Side

1. Install the NEW valve rocker arm cover gasket into the groove of the valve rocker arm cover.
2. Install the NEW valve rocker arm cover bolt grommets into the valve rocker arm cover.
3. Install the valve rocker arm cover onto the cylinder head.
4. Install the valve rocker arm cover bolts. Tighten: Tighten the valve rocker arm cover bolts to 12 N.m (106 lb in).

Valve Rocker Arm Cover Installation - Right Side

1. Install the NEW valve rocker arm cover gasket into the groove of the valve rocker arm cover.
2. Install the NEW valve rocker arm cover bolt grommets into the valve rocker arm cover.
3. Install the valve rocker arm cover onto the cylinder head.
4. Install the valve rocker arm cover bolts. Tighten: Tighten the valve rocker arm cover bolts to 12 N.m (106 lb in).

Oil Level Indicator and Tube Installation

1. Apply sealant GM P/N 12346004 (Canadian P/N 10953480) or equivalent, around the oil level indicator tube 13 mm (0.5 in) below the tube bead.
2. Install the oil level indicator tube into the engine block. Rotate the oil level indicator tube into position.
3. Install the oil level indicator tube bolt. Tighten: Tighten the oil level indicator tube bolt to 12 N.m (106 lb in).
4. Install the oil level indicator into the oil level indicator tube, if required.

Water Pump Installation

1. If reusing the fasteners, apply sealant GM P/N 12346004 (Canadian P/N 10953480) or equivalent, to the threads of the water pump bolts.
2. Install the water pump and the NEW water pump gaskets.
3. Install the water pump bolts. Tighten: Tighten the water pump bolts to 45 N.m (33 lb ft).
4. Install the water pump inlet hose and the water pump inlet hose clamps.
5. Install the fan and water pump pulley and bolts using the J 41240 . Tighten: Tighten the fan and water pump pulley bolts to 25 N.m (18 lb ft).

Exhaust Manifold Installation - Left Side

1. Install the NEW exhaust manifold gaskets.
2. Install the exhaust manifold.
3. Install the spark plug wire shields.
4. If reusing the fasteners, apply threadlock GM P/N 12345493 (Canadian P/N 10953488) or equivalent, to the threads of the exhaust manifold bolts and stud.
5. Install the exhaust manifold bolts and stud. Tighten: Tighten the exhaust manifold bolts and stud on the first pass to 15 N.m (11 lb ft). Tighten the exhaust manifold bolts and stud on the final pass to 30 N.m (22 lb ft).
6. Install the spark plug wires to the spark plug wire retainers.
7. Install the spark plug wires onto the spark plugs.

Exhaust Manifold Installation - Right Side

1. Install the NEW exhaust manifold gaskets.
2. Install the exhaust manifold.
3. Install the spark plug wire shields.
4. If reusing the fasteners, apply threadlock GM P/N 12345493 (Canadian P/N 10953488) or equivalent, to the threads of the exhaust manifold bolts.
5. Install the exhaust manifold bolts. Tighten: Tighten the exhaust manifold bolts on the first pass to 15 N.m (11 lb ft). Tighten the exhaust manifold bolts on the final pass to 30 N.m (22 lb ft).
6. Install the spark plug wires to the spark plug wire retainers.
7. Install the spark plug wires onto the spark plugs.

Clutch Pilot Bearing Installation

1. Install the NEW clutch pilot bearing using a suitable clutch pilot bearing installation tool.
2. Measure to ensure the proper installation depth is obtained.

Engine Flywheel Installation

1. Note the position of the flywheel weights and install the NEW flywheel weights as required. A properly installed flywheel weight will be flush or slightly below flush with the face of the engine flywheel.
2. Install the engine flywheel (1 or 2) to the crankshaft. Align the engine flywheel locator hole to the flywheel locator pin.
3. Install the engine flywheel bolts. Tighten: Tighten the engine flywheel bolts in sequence to 100 N.m (74 lb ft).