GM Service Manual Online
For 1990-2009 cars only

Tools Required

J 8001 Dial Indicator Set

  1. Remove the rear axle housing cover. Refer to Differential Carrier Assembly Assemble .

  2. Object Number: 164245  Size: SH
  3. Rotate the differential case (1) several times in order to seat the bearings.
  4. Mount the J 8001 .
  5. Use a small button on the indicator stem in order to make contact with the near heel end of the tooth.
  6. Set the J 8001 so that the following conditions are met:
  7. • The stem is in line with the gear rotation
    • The stem is perpendicular to the tooth angle
  8. Measure the backlash at three or four points around the ring gear (3). Hold the drive pinion gear stationary when checking backlash.
  9. The lash must not vary over 0.05 mm (0.002 in) around the ring gear (3). If the variation is over 0.05 mm (0.002 in), inspect for the following conditions and correct as necessary:
  10. • Burrs
    • Incorrect bolt torque
    • A distorted case flange
  11. The backlash at the point of minimum lash should be 0.13-0.23 mm (0.005-0.009 in) for all new gears. Adjust the backlash as necessary by increasing the thickness of one bearing shim and decreasing the thickness of the other bearing shim by the same amount.
  12. Transfer 0.05 mm (0.002 in) in bearing shim thickness for each 0.03-mm (0.001-in) change in backlash desired.

    For example, use the following steps in order to decrease the backlash by 0.03 mm (0.001 in):

    8.1. Decrease the thickness of the right bearing shim by 0.05 mm (0.002 in).
    8.2. Increase the thickness of the left bearing shim by 0.05 mm (0.002 in). Refer to Differential Carrier Bearing Preload Adjustment .
  13. Install the rear axle housing cover. Refer to Rear Axle Housing Cover and Gasket Replacement .