GM Service Manual Online
For 1990-2009 cars only

Tools Required

    • J 42168-1 Shim Measuring Tool
    • J 42168-2 Shim Measuring Tool
    • J 42168-9 Shim Measuring Tool
    • J 42168-11 Shim Measuring Tool
    • J-42173-A Differential Holding Fixture

    Object Number: 1041940  Size: SH

    Important: The pinion depth adjustment procedure and shim selection must be performed prior to pinion shaft and housing assembly.

  1. Install the differential carrier (1) onto the J-42173-A  (2).
  2. Notice: Refer to Fastener Notice in the Preface section.

  3. Install 4 M8 x 1.25 bolts (3).
  4. Tighten
    Tighten the bolts to 28 N·m (20 lb ft).


    Object Number: 354433  Size: SH
  5. Install the J 42168-1 into the left bearing race bore of the differential housing.

  6. Object Number: 1491715  Size: SH
  7. Install the J 42168-9  (1) and thumbscrew to the J 42168-1  (2). Tighten the thumbscrew until snug.

  8. Object Number: 354430  Size: SH
  9. Install the J 42168-11  (2), bearings (3 and 6), spacer (5), J 42168-2  (7), and bolt (1) to the pinion housing/cage (4). Tighten the bolt until snug.

  10. Object Number: 1041943  Size: SH
  11. Install the pinion housing/cage assembly (4) into the differential housing.
  12. The use of M8 x 1.25 dowels or long bolts will ease in pinion housing installation and alignment.


    Object Number: 177407  Size: SH

    Important: ALL of the pinion housing/cage bolts must be installed in order to obtain an accurate measurement and correct shim selection.

  13. Install the pinion housing/cage bolts (1).
  14. Tighten
    Tighten the bolts to 28 N·m (20 lb ft).


    Object Number: 1041944  Size: SH
  15. Using a feeler gage, measure the distance between the J 42168-2  (2) and the J 42168-1  (1). Record the dimension as B1.
  16. Subtract the B1 value from a B nominal value of 5 mm (0.197 in). Record that calculation as B2.
  17. Refer to the applicable calculation tables in Spacer and Shim Specifications .


    Object Number: 1491721  Size: SH
  18. Locate the A1 value (1) on the side of the ring gear.
  19. Important: The A1 value is a manufacturing variation between the ring gear and pinion. The A1 value may be higher, lower, or equal to 103.00 mm (4.055 in) nominal value. When subtracting the A nominal value from the A1 value, the B3 calculation may compute to a positive, negative, or zero total.

  20. Subtract the A nominal value of 103.00 mm (4.055 in) from the A1 value. Record the calculation as B3.
  21. Add the B2 value to the B3 value for the proper pinion housing shim thickness. The B3 value may be a positive, negative, or zero value.
  22. Select shims equal to the calculated value. It may be necessary to round the shim or shims total to obtain the proper size shim pack. If the shim thickness calculation is past the midpoint value, round the number higher to the next decimal value.
  23. Refer to Rear Axle Specifications .