GM Service Manual Online
For 1990-2009 cars only

Differential Carrier


    Object Number: 1491418  Size: SH
  1. Clean the differential carrier in solvent.
  2. Inspect for the following conditions:
  3. • Damage to threaded bolt holes (1)
    • Broken flanges (2)
    • Restrictions within the internal oil passages
    • Damaged case or cover sealing surfaces
    • Damage to the O-ring seal grooves (3)
    • Porosity

Differential Carrier Covers


    Object Number: 1491421  Size: SH
  1. Clean the covers in solvent.
  2. Inspect the left side cover output shaft bushing (3) for damage or excessive wear.
  3. Important: Replacing the left side cover bushing requires a NEW left side cover and a NEW bushing. Replacing only the bushing will result in a low press fit condition. Use new bushings where new covers are available without bushings installed.

  4. Inspect the covers for the following conditions:
  5. • Damage to the O-ring seal surface (1)
    • Damage to the axle shaft oil seal bores (2)
    • Restrictions within the internal oil passages
    • Porosity
    • Dents or damage to the exterior of the rear cover that may create interference with the pinion shaft

    Object Number: 1491426  Size: SH
  6. Inspect the pump assembly, some models, for damage. Pump should turn freely without noise.

Drive Pinion Cleaning and Inspection


    Object Number: 1491430  Size: SH
  1. Clean the pinion components in solvent.
  2. Inspect for the following conditions:
  3. • Damage to the nut threads or locking area (1)
    • Worn or scored bearings (2)
    • The pinion housing/cage (4) for damaged bolt holes, broken flanges, restrictions within the oil passages, worn or loose bearing races and/or race bores
    • The pinion shaft (5) for damaged threads, worn splines, or worn or scored gear teeth
    • The pump drive machining (6) for wear, some models