Tools Required

1. Raise the vehicle. Support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.
2. Place a drain pan or suitable container underneath the transfer case.



3. Remove the transfer case oil level/filler plug (1) from the transfer case.



4. Remove the transfer case drain plug (3) from the transfer case and drain the transfer case oil.

Important: An index mark (reference mark) should be placed on the front propeller shaft pinion flange yoke and the front differential pinion flange (if equipped) to ensure that the front propeller shaft is installed in the same position from which it was removed. If this precaution is not observed, a driveline imbalance may result causing vibration, premature component wear or other undesirable conditions.

5. Place an index mark on the front propeller shaft pinion flange yoke and the front differential pinion flange.
6. Remove four bolts, four nuts and the front propeller shaft from the vehicle (if equipped)



7. Remove the front output shaft oil seal (1) from the transfer case using J 26941 and J 23907 (if equipped).
8. Remove the front output shaft plug from the transfer case (if equipped).

Tools Required

1. Install the new front output shaft oil seal into the transfer case (1) using J 37751 (if equipped).
2. Install the new front output shaft plug into the transfer case using J 37751 .
3. Apply J 36850 to the new front output shaft oil seal lip (if equipped).

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.

4. Install the front propeller shaft into the vehicle aligning the reference marks made during the removal. Secure the shaft with four bolts and four nuts (if equipped).

Tighten
Tighten the front propeller shaft bolts and nuts to 50 N·m (37 lb ft).

5. Apply GM P/N 12346004, or the equivalent, to the threaded portion of the transfer case drain plug.
6. Install the transfer case drain plug into the transfer case.

Tighten
Tighten the transfer case drain plug to 28 N·m (21 lb ft).

7. Add approximately 1.7 liters (1.8 qts) of 75W-90 GL4 lubricant, or the equivalent, into the transfer case oil level/filler plug hole. The oil level should be even with the bottom of the oil level/filler plug hole.
8. Apply GM P/N 12346004, or the equivalent, to the threaded portion of the transfer case oil level/filler plug.
9. Install the transfer case oil level/filler plug into the transfer case.

Tighten
Tighten the transfer case oil level/filler plug to 28 N·m (21 lb ft).

10. Lower the vehicle.

Tools Required

1. Raise the vehicle. Support the vehicle. Refer to Lifting and Jacking the Vehicle in General Information.

Important: An index mark (reference mark) should be made on the rear propeller shaft pinion flange yoke and the rear differential pinion flange to ensure that the rear propeller shaft is installed in the same position from which it was removed. If this precaution is not observed, a driveline imbalance may result causing vibration, premature component wear or other undesirable conditions.

2. Place an index mark on the rear propeller shaft pinion flange yoke and the rear differential pinion flange.
3. Remove four bolts, four nuts and rear propeller shaft from the vehicle.



4. Remove the rear output shaft oil seal (1) from the transfer case using J 26941 with J 23907 .

Tools Required

1. Install the new rear output shaft oil seal into the transfer case (1) using J 37751 .
2. Apply J 36850 to the new rear output shaft oil seal lip.

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.

3. Install the rear propeller shaft into the vehicle. Secure the shaft with four bolts and four nuts.

Tighten
Tighten the rear propeller shaft bolts and nuts to 50 N·m (37 lb ft).

4. Check the transfer case oil level. Refer to Oil Replacement .
5. Apply GM P/N 12346004, or the equivalent, to the threaded portion of the transfer case oil level/filler plug.
6. Install the transfer case oil level/filler plug into the transfer case.

Tighten
Tighten the transfer case oil level/filler plug to 23 N·m (17 lb ft).

7. Lower the vehicle.