GM Service Manual Online
For 1990-2009 cars only

    Object Number: 465336  Size: SH

    Important: Install the piston onto the connecting rod with the mark and the arrow (2) oriented toward the front of the engine.

  1. Coat the piston pin with engine oil.
  2. Align the connecting rod with the piston.

  3. Object Number: 261987  Size: SH
  4. Push the piston pin through the connecting rod and the piston bore by hand.
  5. Important: The piston pin snap ring end gap should not be aligned with the pin hole cutout portion of the piston.

  6. Install new snap rings using a small screwdriver. Do not gouge the piston (1) when installing the snap rings.

  7. Object Number: 261801  Size: SH
  8. Ensure that the piston pin snap ring end gap is not aligned with the pin hole cutout portion of the piston.
  9. Notice: Use a piston ring expander to install the piston rings. The rings may be damaged if expanded more than necessary.

  10. Lubricate the piston ring grooves and the piston rings with engine oil.

  11. Object Number: 236178  Size: SH
  12. Install the oil control expander ring.
  13. Install the lower oil control ring.
  14. Install the upper oil control ring.

  15. Object Number: 261803  Size: SH
  16. The lower and upper compression rings differ from each other in thickness, shape and cylinder wall contact surface color. The lower ring (2) is marked R and the upper ring is marked RN.
  17. Install the lower compression ring (2) (second ring) with the manufacturer's mark facing up.

  18. Install the upper compression ring (1) (top ring) with the manufacturer's mark facing up.

  19. Object Number: 261806  Size: SH
  20. The piston ring end gaps must be staggered in order to provide an effective compression seal. After the rings are installed distribute their end gaps as follows:
  21. 12.1. Place the oil ring expander end gap (5) 45 degrees from the front of the piston (6) on the exhaust side of the engine.
    12.2. Place the upper oil ring end gap (7) 45 degrees from the front of the piston (6) on the intake side of the engine.
    12.3. Place the lower oil ring end gap (3) 180 degrees from the upper oil control ring end gap.
    12.4. Place the lower compression ring end gap (5) 45 degrees from the front of the piston (6) on the exhaust side of the engine.
    12.5. Place the upper compression ring end gap (2) 180 degrees from the lower compression ring end gap.