GM Service Manual Online
For 1990-2009 cars only

Special Tools

EN-46745 Piston Pin Retainer Remover and Installer


    Object Number: 1822498  Size: SH

    Important: Install the piston onto the connecting rod with the arrow on top of the piston toward the front oriented toward the front of the engine.

    Important: The cast boss (1) can be in either or both locations depending on displacement.

  1. The cast boss (1), on the underside of the piston, must go to the rear of the block.

  2. Object Number: 1822495  Size: SH
  3. The larger feature (1), at the split line located on one side of the connecting rod, must go to the front of the block.

  4. Object Number: 483298  Size: SH
  5. Assemble the connecting rod and the piston.

  6. Object Number: 1594338  Size: SH

    Notice: Install the piston pin retainers correctly in the retaining groove during assembly in order to avoid engine damage.

  7. Use the following procedure to assemble the piston pin and the retainer:
  8. 4.1. Coat the piston pin with oil.
    4.2. Install one side of one piston pin retainer into the retaining groove using EN-46745 . Rotate the retainer until it is fully seated in the groove.
    4.3. Install the connecting rod and the piston pin.

    Push the piston pin until it bottoms in the previously installed retainer.

    4.4. Install the second piston pin retainer, using EN-46745 .
    4.5. Ensure that the piston moves freely.

    Object Number: 4967  Size: SH

    Notice: Use a piston ring expander to install the piston rings. The rings may be damaged if expanded more than necessary.

  9. Install the following components of the oil control ring assembly (bottom ring):
  10. 5.1. The expander
    5.2. The lower oil control ring
    5.3. The upper control ring
  11. Install the lower compression ring (second ring). Place the manufacturer's mark facing up.
  12. Install the upper compression ring (top ring).

Special Tools

EN-46745 Piston Pin Retainer Remover and Installer

For equivalent regional tools, refer to Special Tools.


    Object Number: 1822498  Size: SH

    Note: Install the piston onto the connecting rod with the arrow on top of the piston toward the front oriented toward the front of the engine.

    Note: The cast boss (1) can be in either or both locations depending on displacement.

  1. The cast boss (1), on the underside of the piston, must go to the rear of the block.

  2. Object Number: 1822495  Size: SH
  3. The larger feature (1), at the split line located on one side of the connecting rod, must go to the front of the block.

  4. Object Number: 2148524  Size: SH
  5. Assemble the connecting rod (2) and the piston (1).

  6. Object Number: 2148518  Size: SH

    Caution: Install the piston pin retainers correctly in the retaining groove during assembly in order to avoid engine damage.

  7. Use the following procedure to assemble the piston pin and the retainer:
  8. 4.1. Coat the piston pin with oil.
    4.2. Install one side of one piston pin retainer into the retaining groove using EN-46745 installer . Rotate the retainer until it is fully seated in the groove.
    4.3. Install the connecting rod and the piston pin.

    Push the piston pin until it bottoms in the previously installed retainer.

    4.4. Install the second piston pin retainer, using EN-46745 installer  (1).
    4.5. Ensure that the piston moves freely.

    Object Number: 2146346  Size: SH

    Caution: Use a piston ring expander to install the piston rings. The rings may be damaged if expanded more than necessary.

  9. Install the following components of the oil control ring assembly (bottom ring):
  10. 5.1. The expander (5)
    5.2. The lower oil control ring (4)
    5.3. The upper control ring (3)
  11. Install the lower compression ring (2). Place the manufacturer's mark facing up.
  12. Install the upper compression ring (1).