GM Service Manual Online
For 1990-2009 cars only

Tools Required

J 42178 Differential Carrier Gear Alignment Arbors

  1. Place the differential carrier on the J 42178 , clamped in the vice, with the ring gear flange downwards.

  2. Object Number: 218773  Size: SH
  3. Install the counterpiece of the J 42178 into the opposing differential carrier bore (1).

  4. Object Number: 218765  Size: SH
  5. Install a NEW differential pinion gear retaining ring (1) into the differential carrier (2).
  6. Thoroughly clean all the components.

  7. Object Number: 218775  Size: SH
  8. Place the shims on the differential side gears.
  9. 5.1. Coat the gears with rear axle lubricant.
    5.2. Coat the shims with rear axle lubricant.
    5.3. Install the thinner (conical) washer toward the differential side gear (1).
    5.4. Install the thicker shim (with notches around the outer edge) toward the carrier.
  10. Place the differential side gears with the previously installed shims into the differential carrier and onto both of the pieces of the J 42178 .

  11. Object Number: 218777  Size: SH
  12. Lubricate with gear lubricant and engage the differential pinion gears (2) and engage the conical washers (1) with the differential side gears. Align them so that they are exactly opposite each other in the carrier window.
  13. Move the differential pinion gear conical washers (1) forward in the intended rotational direction so that they will lead the pinion gears (2) into the mounting position.
  14. Use a ratchet to rotate the J 42178 in order to draw the pinion gears and conical washers into position.
  15. Use a small hammer and drift to assist the washers into position, if necessary.


    Object Number: 218780  Size: SH
  16. Use a deadblow hammer to drive the differential pinion gear shaft (1) into the carrier bore (2) after aligning the differential pinion gears and washers with the pinion gear shaft bores.
  17. Important: Ensure that the retaining ring remains centered in the carrier bore while driving in the pinion gear shaft.

  18. Mount a torque wrench to the J 42178 .

  19. Object Number: 218782  Size: SH
  20. Inspect for proper pinion rotating torque and proper side gear rotating torque.
  21. Specification
    15-30 N·m (11-22 lb ft).

  22. Heat the ring gear to approximately 100°C (212°F).
  23. Important: Do NOT overheat the ring gear. Damage to the ring gear may occur.

  24. Install the ring gear onto the differential carrier.
  25. 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.


    Object Number: 218850  Size: SH
  26. Install NEW ring gear bolts.
  27. Tighten
    The ring gear bolts must be torqued in the sequence shown to 115 N·m (85 lb ft).