GM Service Manual Online
For 1990-2009 cars only
  1. With the manual selector in P (park) position, start engine.
  2. With engine at idle, note any abnormal vibration.
  3. Move the manual selector to N (neutral) position and note any abnormal vibration.
  4. Return the manual selector to P (park) position and turn ignition switch to the LOCK position.
  5. Raise and suitably support the vehicle, Refer to Vehicle Lifting and Jacking in General Information.
  6. Remove the flywheel cover.
  7. Remove the flywheel-to-torque converter bolts.
  8. Rotate torque converter 120 degrees (1/3 turn).
  9. Install the flywheel-to-torque converter bolts.
  10. Tighten
    Tighten the flywheel-to-torque converter bolts to 19 N·m (14 lb ft).

  11. Install flywheel cover.
  12. Lower vehicle.
  13. With the manual selector in P (park) position, start the engine.
  14. If any abnormal vibration still exists, repeat this procedure until the best possible balance is obtained. For more information on torque converter evaluation, refer to Automatic Transaxle diagnosis.