GM Service Manual Online
For 1990-2009 cars only

Tools Required

    • J 34178 Spreader Gage Adapter
    • J 45222 Axle Housing Spreader
    • J 8001 Dial Indicator Set
    • J 24429 Bearing Backlash Spanner

Removal Procedure

Important: Group and mark the shims together as originally removed. If you remove or replace the ring and pinion gearset, perform the bearing preload, backlash, and gear tooth contact pattern check in order to ensure proper contact of the gears. If you reinstall or replace the differential carrier without replacing any other component (i.e. pinion and ring gear set, bearings. etc.) then you may reinstall the carrier with the original shims in their original locations. Always perform a gear tooth contact pattern check, even when you remove only the carrier.

  1. Raise the vehicle. Refer to Lifting and Jacking the Vehicle .
  2. Remove the spare tire.
  3. Remove the rear axle tie rod. Refer to Rear Axle Tie Rod Replacement .
  4. Remove the axle shafts. Refer to Rear Axle Shaft Replacement .
  5. Loosen the bearing cap bolts.
  6. Do not remove the bearing cap bolts at this time.

    Important: The following procedure is for the right side of the 9.5 LD inch axle.

  7. For vehicle equipped with the 9.5 LD inch axle, remove the differential bearing adjuster nut lock.

  8. Object Number: 788485  Size: SH

    Important: The following service procedure is for vehicles equipped with the 8.0/8.6 inch axles.

  9. Install the J 45222 onto the axle housing as shown.
  10. Install the J 8001-1  (2), the J 8001-2  (3), the J 34178  (4, 6), and the J 8001-3  (5) as shown.
  11. Preload the J 8001-3  (5) approximately 3/4 of a turn clockwise.
  12. Rotate the indicator housing to align the indicator needle of the J 8001-3  (5) and the dial indicator face to ZERO.
  13. Spread the axle housing by turning the clevis screw of the J 34178 while observing the J 8001-3 .
  14. Spread the housing just enough to remove the differential assembly. Do not spread the housing more than 1.02 mm (0.040 in).


    Object Number: 788491  Size: SH
  15. Remove the bearing caps bolts and the caps. Mark the bearing caps left and right.
  16. Caution: To prevent personal injury and/or component damage, support the differential case when removing the case from the axle housing. If the case is not supported, the differential case could fall and cause personal injury or damage to the differential case.

    Notice: When removing the differential case from the axle housing, do not damage the cover gasket surface. If the cover gasket surface is damaged, lubricant may leak from the axle and cause premature failure of the axle assembly.


    Object Number: 788480  Size: SH
  17. For vehicles equipped with the 8.0/8.6 inch axles, remove the differential from the axle housing using a pry bar and a block of wood.
  18. For vehicles equipped with the 9.5 LD inch axle, use the J 24429 to loosen the differential bearing adjuster nut.
  19. Remove the 9.5 LD inch axle from the differently assembly.
  20. Remove the bearing cups, the shims, and the spacers as necessary.
  21. Mark the cups and shims left and right and in the proper order as necessary. Place the cups and the shims with the bearing caps.

  22. Remove the J 8001-1 , the J 8001-2 , the J 34178 , and the J 8001-3 .
  23. Remove the J 45222 .
  24. Remove the differential side bearings, if necessary. Refer to Differential Side Bearings Replacement .
  25. Remove the ring gear, if necessary. Refer to Drive Pinion and Ring Gear Replacement .

Installation Procedure

  1. Install the ring gear, if necessary. Refer to Drive Pinion and Ring Gear Replacement .
  2. Install the differential side bearings, if necessary. Refer to Differential Side Bearings Replacement .
  3. Lubricate the differential side bearings with axle lubricant. Use the proper fluid. Refer to Fluid and Lubricant Recommendations .

  4. Object Number: 788484  Size: SH
  5. For vehicles equipped 8.0/8.5 inch axles, install the J 45222 onto the axle housing as shown.

  6. Object Number: 788485  Size: SH
  7. Install the J 8001-1  (2), the J 8001-2  (3), the J 34178  (4, 6), and the J 8001-3  (5) as shown.
  8. Preload the J 8001-3  (5) approximately 3/4 of a turn clockwise.
  9. Rotate the indicator housing to align the indicator needle of the J 8001-3  (5) and the dial indicator face to ZERO.
  10. Spread the axle housing by turning the clevis screw of the J 34178 while observing the J 8001-3 .
  11. Spread the housing just enough to install the differential assembly. Do not spread the housing more than 1.02 mm (0.040 in).


    Object Number: 667660  Size: SH
  12. Place the case, with the bearing cups installed, into the axle housing.
  13. Support the case in order to keep the case from falling out of the axle housing.


    Object Number: 788491  Size: SH
  14. Install the bearing caps and the bolts.
  15. Do not torque the bearing cap bolts at this time.

  16. Adjust the differential side bearing preload. Refer to Differential Carrier Bearing Preload Adjustment .
  17. Adjust the backlash. Refer to Backlash Adjustment .
  18. Perform a gear tooth contact pattern check. Refer to Gear Tooth Contact Pattern Inspection .
  19. Notice: Refer to Fastener Notice in the Preface section.

  20. Tighten the bearing cap bolts.
  21. Tighten
    Tighten the bearing cap bolts to 85 N·m (63 lb ft).

  22. Install the axle shafts. Refer to Rear Axle Shaft Replacement .
  23. Install the rear axle tie rod. Refer to Rear Axle Tie Rod Replacement .
  24. Install the spare tire.
  25. Lower the vehicle.