GM Service Manual Online
For 1990-2009 cars only

Isolating Vibration

Notice: Some engine/transaxle combinations cannot be balanced in this manner due to restricted access or limited clearances between the torque converter bolts and the engine. Ensure that the bolts do not bottom out in the lug nuts or the torque converter cover which could dent and cause internal damage.

To isolate and correct a flywheel or torque converter vibration, separate the torque converter from the flywheel to determine if vibration is in the engine or transmission.

  1. With the engine at idle speed and the transmission in PARK or NEUTRAL, observe the vibration.
  2. Turn the engine OFF.
  3. Raise and suitably support the vehicle.
  4. Refer to Lifting and Jacking the Vehicle in General Information.

  5. Remove the transmission converter cover bolts and the cover.
  6. Refer to Torque Converter Cover Replacement .

  7. Verify the bolt torques attaching the converter to the flywheel are to specification.
  8. Remove the bolts attaching the converter to the flywheel.
  9. Refer to Flywheel to Torque Converter Bolt Replacement .

  10. Slide the torque converter away from the flywheel.
  11. Rotate the flywheel (1) to inspect for defects or damage.
  12. Refer to Engine Flywheel Cleaning and Inspection in Engine Mechanical.

  13. Rotate the torque converter to inspect lugs and pilot (2) for damage. Verify presence of balance weight on O.D. of torque converter.
  14. Lower the vehicle.
  15. With the engine at idle speed and the transmission in PARK or NEUTRAL, observe the vibration.
  16. Refer to Engine Related Vibration in Vibration Diagnosis and Correction.

  17. Turn the engine OFF.

Installing Torque Converter

  1. Raise and suitably support the vehicle.
  2. Refer to Lifting and Jacking the Vehicle in General Information.


    Object Number: 572368  Size: SH
  3. Align the torque converter pilot (2) in the engine crankshaft (3) and slide the torque converter up against the flywheel.
  4. Hand install the first torque converter to flywheel bolt while holding the converter flush against the flywheel
  5. Index the torque converter/flywheel two bolt positions. Verify the torque converter lug is flush against the flywheel. If a gap exists (1 mm or greater), unfasten and re-engage pilot per Step 2.
  6. Install remaining torque converter to flywheel bolts. Refer to Flywheel to Torque Converter Bolt Replacement .
  7. Lower the vehicle.
  8. With the engine at idle speed and the transmission in PARK or NEUTRAL, observe the vibration.
  9. Refer to Noise and Vibration Analysis .

    Repeat this procedure until you obtain the best possible balance.

  10. Install the transmission converter cover bolts and the cover.
  11. Refer to Torque Converter Cover Replacement .