GM Service Manual Online
For 1990-2009 cars only

Special Tools

    • J 45059 Angle Meter
    • J-42094-A Remover/Installer Kit
    • DT-46853 Pinion Oil Seal Installer
    • DT-47735 Flange Holder
    • DT-47736 Flange Remover

Removal Procedure

  1. Raise and support the vehicle. Refer to Lifting and Jacking the Vehicle .
  2. Remove the left and right mufflers. Refer to Muffler Replacement .
  3. Remove the propeller shaft. Refer to Two-Piece Propeller Shaft Replacement .
  4. Place a drain pan under the pinion flange.
  5. Important: The rear axle lubricant must be completely drained to ensure the proper friction modifier fill specification.

  6. Remove the rear axle housing drain plug from the axle housing.
  7. Remove the rear axle housing fill plug from the axle housing.

  8. Object Number: 1293727  Size: SH
  9. Center punch alignment marks (1) on the pinion flange, the pinion flange nut  (2), and the pinion shaft end .

  10. Object Number: 1341911  Size: SH
  11. Using an inch pound torque wrench, check and record the rotational torque on the pinion shaft. Torque should be between 2 and 4 lb in.

  12. Object Number: 1553235  Size: SH
  13. Install the DT-47735 (1) on the pinion flange.
  14. Remove the pinion flange nut.

  15. Object Number: 1553234  Size: SH
  16. Using the DT-47736 (1), remove the pinion flange.

  17. Object Number: 1293734  Size: SH
  18. Using a seal puller, remove the pinion seal.

Installation Procedure

  1. Inspect the pinion shaft seal surface for nicks and burrs. Minor nicks and burrs can be removed with crocus cloth. If damaged, replace the pinion flange.
  2. Clean the threads on the pinion shaft and pinion nut.
  3. Coat the pinion shaft splines with recommended gear oil.
  4. Lubricate the seal with the recommended gear oil.

  5. Object Number: 1293737  Size: SH
  6. Using DT-46853 , install the new pinion shaft seal until the seal is flush with the differential housing.
  7. Install the pinion flange on to the pinion shaft aligning the punch marks.

  8. Object Number: 1553235  Size: SH
  9. Install the DT-47735 (1) on the pinion flange.
  10. Apply thread locking compound onto the threads of the pinion shaft.
  11. Notice: Refer to Fastener Notice in the Preface section.

    Important: Do not overtighten the pinion nut. If the nut is overtightened the preload will be exceeded and the differential will have to be changed.


    Object Number: 1293727  Size: SH
  12. Tighten the pinion nut until the three punch marks are aligned.
  13. Tighten
    Using J 45059 , tighten the nut to a position no more than 5 degrees past the punch marks (1).


    Object Number: 1341911  Size: SH
  14. Using a inch pound torque wrench, recheck the rotational torque on the pinion shaft. The torque should be between 2 and 4 lb in.
  15. Install the drain plug.
  16. Tighten
    Tighten the drain plug to 27 N·m (20 lb ft).

  17. Refill the rear axle housing with 1.0 liter (1.0 qt) of Synthetic Gear Oil 75W-140 GM P/N 89021809.
  18. Using a graduated measuring cup, add 25 ml (1.0 oz) of Limited Slip Differential Friction Modifier GM P/N 89021958 to the rear axle housing.
  19. Fill the rear axle housing with the remaining 0.575 liter (0.644 qt) of Synthetic Gear Oil 75W-140 GM P/N 89021809.
  20. The oil level should be even with the bottom of the rear axle housing filler plug hole.

  21. Install the rear axle housing oil level fill plug with a new gasket and the lubricant tag into the rear axle housing.
  22. Tighten
    Tighten the fill plug to 27 N·m (20 lb ft).

  23. Remove the drain pan.
  24. Install the propeller shaft. Refer to Two-Piece Propeller Shaft Replacement .
  25. Install the left and right mufflers. Refer to Muffler Replacement .
  26. Lower the vehicle. Refer to Lifting and Jacking the Vehicle .