GM Service Manual Online
For 1990-2009 cars only

    Object Number: 630689  Size: SH
  1. Inspect the differential for the following:
  2. • A damaged or restricted vent tube (1)
    • Damaged oil seal bores (2)
    • Damaged clutch pump check valve bore or bolt threads (3)
    • Worn or scored pinion housing bore (4)
    • Damage to the exterior of the differential (5)
    • Damaged axle shaft splines (2) and /or
    • Missing axle shaft snap rings

    Object Number: 630657  Size: SH
  3. Inspect the pinion and housing assembly for the following:
  4. • Worn or damaged splines (1)
    • Abnormal pinion gear tooth wear (2)
    • Damaged pinion housing O-ring seal groove (3)
    • Damaged oil seal (4)
    • Worn bearings
    • Rotate the pinion shaft by hand. The shaft should rotate with minimal resistance and no coarse or rough feeling.