GM Service Manual Online
For 1990-2009 cars only

Piston and Piston Pin Installation Procedure


    Object Number: 204785  Size: SH

    Important: The arrow located on top of the piston must point toward the front of the engine.

    Important: The connecting rod is nondirectional and may be assembled/reassembled to the piston in either direction.

  1. Assemble the piston and piston pin to the connecting rod. Properly orient the piston when reusing a marked connecting rod.
  2. Align the piston pin bore with the connecting rod pin bore.
  3. Slide the piston pin (4) into the piston and the connecting rod (3).
  4. Install new piston pin retainers (1) by working the retainers into their grooves until a positive lock is heard and felt.
  5. Important: New piston pin retainers must be used. Never reuse the piston pin retainers.

  6. Ensure that the piston pin retainers are fully seated in their grooves.
  7. Repeat these procedures for the remaining pistons.

Piston Ring Installation Procedure


    Object Number: 240809  Size: SH
  1. Properly orient the oil control ring expander as shown before installation. The ends of the expander must be facing toward the top of the piston.

  2. Object Number: 204801  Size: SH
  3. Using a piston ring expander, install the oil control ring assembly using the following procedure:
  4. 2.1. Install the expander ring (3).
    2.2. Install the two oil scraper rings (4). Expand the rings only enough to clear the piston diameter. Overexpanding the piston rings will distort or crack the rings.

    Object Number: 490763  Size: SH
  5. Install the second and top piston rings using the piston ring expander. Ensure that you do not overexpand the rings.

  6. Object Number: 316688  Size: SH
  7. Once the rings are installed, set the ring gaps for the oil control, second and top ring as follows. Use the piston locating arrow for reference.
  8. 4.1. Lower oil control ring -- position 1.
    4.2. Upper oil control ring -- position 2
    4.3. Top Ring -- position 3.
    4.4. Oil control ring expander -- position 4.
    4.5. Second ring -- position 5.

Connecting Rod Bearing Installation Procedure

    Important: If the connecting rod bearings have been used in a running engine, you must replace them with NEW connecting rod bearings for reassembly.

  1. Clean the connecting rod and the connecting rod cap bearing bore with a lint-free cloth.

  2. Object Number: 53223  Size: SH
  3. Clean all the oil from behind the connecting rod bearing halves.
  4. Install new upper connecting rod bearings into position. Roll the bearing into position so that the lock tang engages the alignment slot. The bearing must fit flush in the connecting rod.
  5. Install new lower connecting rod bearings into position in the connecting rod cap. Roll the bearing into position so that the lock tang engages the alignment slot. The bearings must fit flush with the connecting rod cap.