GM Service Manual Online
For 1990-2009 cars only

Important: Do not disassemble the countershaft. Individual components of the countershaft are not serviced. A damaged or worn countershaft must be replaced as a complete assembly.

  1. Clean the countershaft in a suitable solvent. Air dry the countershaft.
  2. Inspect the countershaft for cracks.
  3. Replace a cracked countershaft.
  4. Inspect the countershaft gears for the following conditions:
  5. • Scuffed gear teeth
    • Nicked gear teeth
    • Burred gear teeth
    • Broken gear teeth
    • High spots (Small shiny spots on the gear teeth mating surfaces) that could cause gear noise
  6. Lubricate the countershaft bearings with the proper transmission lubricant.
  7. Replace the bearing assembly if any of the following conditions exist:
  8. • Roughness of rotation
    • Burrs
    • Pitted condition
  9. Replace the bearing race and inspect the mating parts If the following conditions exist:
  10. • Scoring
    • Wear
    • Discoloration from overheating