GM Service Manual Online
For 1990-2009 cars only

Differential Case


    Object Number: 58600  Size: SH
  1. Clean the differential case components in solvent.
  2. Inspect the components for the following:
  3. • Cracks or other damage
    • Damage to threaded bolt holes
    • Unusual wear, scoring, or grooves in the clutch pack area
    • Scored or damaged case side bearing mounting flanges

Gears and Shafts


    Object Number: 58616  Size: SH
  1. Clean the gears and shafts with solvent.
  2. Inspect the gears for the following:
  3. • Chips or cracks
    • Pitting
    • Heat discoloration
    • Unusual wear
    • Excessive wear or scoring in the side gear (1) pin bores
    • Wear, grooves, or scoring on the side gear pin
    • Scored or worn side gear washers (2)
    • Unusual wear or grooves on the output gear (3) splines
    • Damaged to the ring gear threaded bolt holes
    • Damage to the ring gear vehicle speed sensor reluctor ring lobes

    Object Number: 58607  Size: SH
  4. Inspect the shafts for the following:
  5. • Unusual wear
    • Grooved, worn, or damaged splines
    • Damaged C-clip grooves

Clutch Discs and Plates


    Object Number: 354424  Size: SH
  1. Clean the discs and plates with solvent.
  2. Inspect the discs and plates for the following:
  3. • Unusual wear, scoring, or grooves on the separator plate friction surfaces (1)
    • Friction plates with uneven wear or worn friction material (2 and 3)
    • If any one plate or disk in either the left or right pack show signs of wear or scoring, replace the complete pack on both sides.
    • Bent or warped plates or discs
    • Lay the plates and discs on a flat surface and inspect for warpage
    • A worn, scored, or collapsed bellville washer (4)

Bearings and Races


    Object Number: 1465  Size: SH
  1. Inspect the bearing rollers and cups for the following:
  2. • Pitting
    • Scoring or grooves
    • Excessive wear or other damage

    Object Number: 1458  Size: SH
  3. Inspect the bearing rollers and cups for heat discoloration.
  4. Heat discoloration ranges from a faint yellow to a dark blue color. This discoloration may result from an overload or improper lubrication. Excessive heat causes softening of the rollers and cups. Bearings or cups with sign of heat discoloration must be replaced.


    Object Number: 1648  Size: SH
  5. Inspect for bent bearing cages.

  6. Object Number: 1456  Size: SH
  7. Inspect for damaged bearing cages.

  8. Object Number: 1491713  Size: SH
  9. Inspect the left side cover output shaft bushing (8) for worn or missing needle bearings.