GM Service Manual Online
For 1990-2009 cars only

Differential Housing

    Warning: Refer to Safety Glasses Warning in the Preface section.


    Object Number: 1978332  Size: MH
  1. Clean the differential housing in solvent.
  2. Clean and inspect the differential housing for the following:
  3. • The mounting bolt threads (2)
    • The case cover bolt hole threads (3)
    • The sealing surface for nicks or burrs (5)
    • The drain plug hole threads (8)
    • The axle seal area (7)
    • The drive pinion seal area (1)
    • The rear differential support bushing bore (6)
    • Front right side differential support bushing bore (9)
    • Vent for operation (4)
    • Cracks in the housing, if removed

    Object Number: 777584  Size: SH
  4. Clean the oil passage between (1) and (2), in the axle bearing bore.

Differential Carrier Cover

    Warning: Refer to Safety Glasses Warning in the Preface section.


    Object Number: 1978337  Size: SH
  1. Clean the differential carrier cover in solvent.
  2. Clean and inspect the differential carrier cover for the following:
  3. • Clean the oil passage between (2)
    • Inspect the cover flat (3) for nicks and burrs.
    • Inspect the race and shim surfaces (1)

    Object Number: 1978338  Size: SH
  4. Inspect the differential carrier cover exterior for the following:
  5. • The mounting bolt threads (1)
    • The axle seal mounting surface (2)