GM Service Manual Online
For 1990-2009 cars only

Special Tools

    • EN 46121 Connecting Rod Guide Pin Set
    • EN 46745 Piston Pin Clip Remover/Installer

For equivalent regional tools, refer to Special Tools.

Piston and Piston Pin Installation Procedure


    Object Number: 1210818  Size: SH

    Note: The piston is directional and must be installed in the engine block in the proper direction. The dot on the top of the piston must face the front of the engine.

  1. Lubricate the piston pin bores in the piston and the connecting rod with or equivalent. Refer to Adhesives, Fluids, Lubricants, and Sealers for the recommended lubricant.
  2. Assemble the piston and piston pin to the connecting rod. Properly orient the piston when reusing a marked connecting rod.
  3. Align the piston pin bore with the connecting rod pin bore.
  4. Slide the piston pin into the piston and the connecting rod.

  5. Object Number: 1210796  Size: SH

    Note: New piston pin retainers must be used. Never reuse the piston pin retainers.

  6. Install NEW piston pin retainers using the EN 46745 installer . Align the EN 46745 installer to the notch (1) in the piston.
  7. Ensure that the piston pin retainers are fully seated in their grooves.
  8. 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: 1316533  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 2 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: 1316504  Size: SH
  5. Install the second and top piston rings using the 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 location 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


    Object Number: 1313403  Size: SH

    Note: 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. Clean all the oil from behind the connecting rod bearing halves.
  3. 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.
  4. Install the EN 46121 pin into the connecting rod bolt holes.

  5. Object Number: 1313743  Size: SH
  6. 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.