GM Service Manual Online
For 1990-2009 cars only

A noise or vibration that is noticeable when the vehicle is in motion may not be the result of the transmission. If a noise or vibration is noticeable in the PARK or the NEUTRAL position with the engine running at idle, but is less noticeable as the engine RPM increases, the cause may be from poor engine performance.

  1. Inspect the tires for the following conditions:
  2. • Uneven wear
    • Imbalance
    • Mixed sizes
    • Mixed radial and bias ply.
  3. Inspect the suspension components for the following conditions:
  4. • Misalignment and wear
    • Loose fasteners.
  5. Inspect the Engine/Transmission mounts for the following conditions:
  6. • Excessive wear or damage
    • Loose mounting bolts.
  7. Inspect the transmission case mounting holes for the following conditions:
  8. • Missing bolts, nuts or studs
    • Stripped threads
    • Cracks
  9. Inspect the flywheel for the following conditions:
  10. • Missing or loose bolts
    • Cracks
    • Imbalance
  11. Inspect the torque converter for the following conditions:
  12. • Missing or loose bolts or lugs
    • Missing or loose balance weights
    • Imbalance