GM Service Manual Online
For 1990-2009 cars only

Removal Procedure


    Object Number: 178458  Size: SH
  1. Remove the automatic transmission, if equipped. Refer to Transmission Replacement for the 4L60-E transmission or Transmission Replacement for the 4L80-E transmission.
  2. Important: Note the position and direction of the engine flywheel before removal.

  3. Remove the engine flywheel bolts.
  4. Remove the automatic transmission engine flywheel.
  5. Clean and inspect the engine flywheel. Refer to Engine Flywheel Cleaning and Inspection .
  6. Install 2 M11x1.5 mm bolts (1) to the threaded holes of the spacer, if applicable.
  7. Rotate the bolts clockwise to remove the spacer.

  8. Object Number: 642276  Size: SH
  9. Remove the spacer from the rear of the crankshaft, if applicable.

Installation Procedure

Important: 

   •  The flywheel does not use a locating pin for alignment and will not initially seat against the crankshaft flange or spacer (if applicable), but will be pulled onto the crankshaft by the engine flywheel bolts. This procedure requires a three stage tightening process.
   • Certain applications (4.8 L manual transmissions or all 6.0 L) require a spacer and longer bolts for proper flywheel position.


    Object Number: 642276  Size: SH
  1. Install the spacer (if applicable) onto the rear of the crankshaft.

  2. Object Number: 178458  Size: SH
  3. Install the automatic transmission engine flywheel to the crankshaft.
  4. Important: Longer flywheel bolts must be used on applications using a flywheel spacer.

  5. Apply threadlock to the threads of the flywheel bolts. Refer to Adhesives, Fluids, Lubricants, and Sealers for the correct part number.
  6. Notice: Refer to Fastener Notice in the Preface section.


    Object Number: 63174  Size: SH
  7. Install the engine flywheel bolts.
  8. Tighten

    1. Tighten the engine flywheel bolts a first pass in sequence to 20 N·m (15 lb ft).
    2. Tighten the engine flywheel bolts a second pass in sequence to 50 N·m (37 lb ft).
    3. Tighten the engine flywheel bolts a final pass in sequence to 100 N·m (74 lb ft).
  9. Install the automatic transmission. Refer to Transmission Replacement for the 4L60-E transmission or Transmission Replacement for the 4L80-E transmission.