GM Service Manual Online
For 1990-2009 cars only

Removal Procedure

  1. Remove the transmission from the vehicle. Refer to Transmission Removal in Manual Transmission -- M59 or Transmission Replacement in Automatic Transmission 4 Speed.
  2. Remove the pressure plate assembly and the clutch disc to manual transmission equipped vehicles only. Refer to Clutch.
  3. Mark the flywheel-to-engine position.
  4. Remove the six flywheel retaining bolts.
  5. Remove the flywheel from the crankshaft.

  6. Object Number: 166975  Size: SH
  7. Remove the rear main seal (1).

Installation Procedure


    Object Number: 166975  Size: SH
  1. Install the new rear main seal (1).
  2. Notice: Apply the proper amount of the sealant to the fastener when assembling this component. Excessive use of the sealant can prohibit the component from being assembled properly or allow the fastener to loosen. A component or fastener that is not assembled properly can loosen or fall off leading to extensive engine damage.

  3. Apply the GM P/N 12345493 or an equivalent to the flywheel retaining bolt threads.
  4. Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

    Important: After the rear main seal housing bolts are tightened, the gasket may extend past the rear main seal housing. Trim the excess with a sharp knife so the gasket is flush with the cylinder block.

  5. Install the flywheel. Secure the six flywheel retaining bolts.
  6. Tighten
    Tighten the flywheel retaining bolts to 78 N·m (58 lb ft).

  7. Install the pressure plate assembly and the clutch disc for the manual transmission equipped vehicles only.
  8. Install the transmission to the vehicle. Refer to Transmission Installation in Manual Transmission -- M59 or Transmission Installation in Automatic Transmission -- 4 Speed.