Differential Replacement

REMOVAL PROCEDURE





1. Raise the vehicle. Support the vehicle. Refer to Vehicle Lifting Points.
2. Place a drain pan or suitable container under the rear axle housing.
3. Remove the rear axle housing oil level/filler plug (1) from the rear axle housing.
4. Remove the rear axle housing drain plug (2) from the rear axle housing.
5. Drain the rear axle housing.
6. Remove the rear tire and wheel assemblies. Refer to Wheel Removal in Tires and Wheels.
7. Remove the rear brake drums from the rear axle. Refer to Brake Drum Replacement in Drum Brakes.





8. Remove both rear axle shafts from the rear axle housing. Refer to Axle Shaft Replacement in Axle Shaft, Conventional Fixed/Floating.

IMPORTANT: To ensure rear propeller shaft balance, an index mark (reference mark) (1) must be placed on the differential pinion flange and the rear propeller shaft flange so that the rear propeller shaft (2) can be installed in the same position from which it was removed. If this procedure is not followed, a driveline imbalance may result causing vibration, premature component wear or other undesirable characteristics.

9. Remove the following from the vehicle:
^ The four bolts
^ The four nuts
^ The rear propeller shaft (2)





10. Loosen both rear control arm through bolts and nuts.
11. If the vehicle is Load Sensing Proportioning Valve (LSPV) equipped, remove the two bolts securing the LSPV spring bracket to the upper control arm.
12. Remove the four bolts from the rear control arm ball joint boss (3). Separate the rear control arm ball joint boss from the differential carrier.





13. If vehicle equipped, remove the two bolts and the rear wheel speed sensor cover (1) from the differential carrier (2).





14. If vehicle equipped, remove the electrical connector (1) from the rear wheel speed sensor.





15. Remove the eight nuts and the differential carrier (2) from the rear axle housing (1).
16. Clean the oil and sealant from the differential carrier and the rear axle housing mating surfaces.
17. Inspect the differential carrier.

INSTALLATION PROCEDURE





1. Apply RTV silicone gasket and sealer GM P/N 12346240, or equivalent, to the differential carrier mating surface (1) on the rear axle housing (2).





2. Install the differential carrier into the rear axle housing. Secure the differential carrier with eight nuts (1).
^ Tighten the differential carrier nuts to 55 Nm (41 ft. lbs.).

NOTICE: Refer to Fastener Notice in Service Precautions.





3. If vehicle equipped, install the electrical connector (1) to the rear wheel speed sensor.





4. If vehicle equipped, install the rear wheel speed sensor cover (1) to the differential carrier (2). Secure the cover with two bolts.
^ Tighten the rear wheel speed sensor cover bolts to 15 Nm (111 ft. lbs.).





5. Install the rear control arm ball joint boss (3) to the differential carrier (2). Secure ball joint boss with four bolts.
^ Tighten the rear control arm ball joint boss bolts to 50 Nm (37 ft. lbs.).
^ Tighten the rear control arm through bolts and nuts to 90 Nm (66 ft. lbs.).





6. If vehicle equipped, install the LSPV load sensing spring bracket to the upper control arm. Secure the bracket with two bolts.
^ Tighten the load sensing spring bracket bolts to 18 to 25 Nm (13.5 to 20.0 ft. lbs.).

7. Install the rear propeller shaft (2) into the vehicle.
Secure with four nuts and bolts.
^ Tighten the rear propeller shaft nuts and bolts to 50 Nm (37 ft. lbs.).

IMPORTANT: Use the index (reference) marks made in the removal procedure to ensure correct rear propeller shaft installation.

8. Install both rear axle shafts into the rear axle housing. Refer to Axle Shaft Replacement in Axle Shaft, Conventional Fixed/Floating.
9. Install the rear brake drums to the rear axle. Refer to Brake Drum Replacement in Drum Brakes.
10. Install the rear tire and wheel assemblies. Refer to Wheel Installation in Tires and Wheels.
11. Apply GM P/N 12346004, or equivalent, to the threaded portion of the rear axle housing drain plug.





12. Install the rear axle housing drain plug (2) into the rear axle housing.
^ Tighten the rear axle housing drain plug to 25 Nm (18 ft. lbs.).

13. Refill the rear axle housing with approximately 2.2 liters (4.6 pts.) of 80W-90 GL5 lubricant GM P/N 12345977, or equivalent. The oil level should be even with the bottom of the rear axle housing oil level/filler plug hole.
14. Install the rear axle housing oil level/filler plug (1) into the rear axle housing.
^ Tighten the rear axle housing oil level/filler plug to 43 Nm (32 ft. lbs.).

15. Remove the drain pan from under the rear axle housing.
16. Lower the vehicle.