Notice: Perform TDC Offset Recovery procedure if the timing chain, timing gears, engine front cover, crankshaft position sensor, crankshaft or other components affecting the timing are replaced.

1. Disconnect the battery negative cables from the batteries.

•	For the front battery, refer to Battery Cable Replacement in Engine Electrical.

•	For the auxiliary battery, refer to Battery Cable Replacement in Engine Electrical.

2. Drain the cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.
3. Remove the fan shroud from the radiator. Refer to Fan Shroud Replacement in Engine Cooling.
4. Remove the drive belt from the pulleys. Refer to Drive Belt Replacement .
5. Raise the vehicle and support with a safety stand.
6. Remove the water pump from the engine block. Refer to Water Pump Replacement in Engine Cooling.
7. Remove the crankshaft balancer from the crankshaft. Refer to Crankshaft Balancer Replacement .
8. Remove the crankshaft position sensor from the engine front cover.



9. Remove the fuel injection drive gear from the fuel injection pump.




Important: Mark the fuel line clips, so that they can be re-installed on the proper stud.

10. Remove the bolts from the engine front cover.



11. Remove the engine front cover from the engine block.
12. Clean and inspect the sealing surface of the engine block.

Tools Required

J 22102 Front Cover Seal Installer

1. Use the J 22102 to install the new front crankshaft front oil seal.



2. Apply a 2 mm (3/32 in) bead of anaerobic sealant GM P/N 1052357 or equivalent to the engine front cover.
3. Apply a 5 mm (3/16 in) bead of RTV sealant to the engine front cover sealing the surface that mates against the oil pan.



4. Install the engine front cover to the engine block.




Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

5. Install the engine front cover bolts.

Tighten
Tighten the nuts to 40 N·m (30 lb ft).




6. Install the attaching bolts and the fuel injection pump studs.

Tighten
Tighten the nuts to 40 N·m (30 lb ft).




7. Install the fuel injection pump drive gear and bolts to the fuel injection pump.

Tighten
Tighten the bolts to 25 N·m (20 lb ft).

8. Install the crankshaft balancer to the crankshaft. Refer to Crankshaft Balancer Replacement .



9. Install the crankshaft position sensor to the engine front cover.
10. Install the water pump to the engine block. Refer to Water Pump Replacement in Engine Cooling.
11. Remove the safety stands and lower the vehicle. Refer to Vehicle Lifting and Jacking in General Information.
12. Install the drive belt on the pulleys. Refer to Drive Belt Replacement .
13. Install the fan shroud to the radiator. Refer to Fan Shroud Replacement in Engine Cooling.
14. Fill the cooling system. Refer to Cooling System Draining and Filling in Engine Cooling.
15. Connect the battery negative cables to the batteries.

•	For the front battery, refer to Battery Cable Replacement in Engine Electrical.

•	For the auxiliary battery, refer to Battery Cable Replacement in Engine Electrical.

16. Perform the TDC offset adjustment. Refer to Fuel Injection Pump Top Dead Center Offset Adjustment in Engine Controls-6.5L.