GM Service Manual Online
For 1990-2009 cars only

Tools Required

    • KM-470-B Angular Torque Gage
    • J 24086-B (KM-427) Piston Pin Remover/Installer
    • J 45059 Angle Meter

Removal Procedure

    Caution: Refer to Safety Glasses Caution in the Preface section.


    Object Number: 1241699  Size: SH
  1. Remove the cylinder head with the intake manifold and exhaust manifold attached. Refer to Cylinder Head Replacement .
  2. Remove the oil pan. Refer to Oil Pan Replacement .
  3. Remove the oil pump/pickup tube bolts.
  4. Remove the oil pump/pickup tube.

  5. Object Number: 1241701  Size: SH
  6. Move the piston to the bottom of the piston stroke.
  7. Mark the connecting rod cap.
  8. Remove the connecting rod cap bolts.
  9. Remove the connecting rod cap and lower connecting rod bearing.
  10. Remove the upper piston connecting rod bearing.
  11. Ridge ream the cylinder wall.

  12. Object Number: 1241703  Size: SH

    Caution: Handle the piston carefully. Worn piston rings are sharp and may cause bodily injury.

  13. Remove the piston.
  14. Use a piston ring expander tool to expand the piston rings.
  15. Remove the piston rings.

  16. Object Number: 1241706  Size: SH
  17. Remove the piston pin from the piston and connecting rod assembly using the J 24086-B  (1).
  18. Separate the piston from the connecting rod.

Installation Procedure


    Object Number: 1241706  Size: SH

    Caution: Avoid contact with moving parts and hot surfaces while working around a running engine in order to prevent physical injury.

  1. Align the notch on the piston and connecting rod so that the proper sides will be facing the front of the engine.
  2. Install the piston pin guide through the piston and the connecting rod.
  3. Coat the piston pin with clean oil.
  4. Install the piston pin into the opposite side of the piston.
  5. Install the piston pin into the piston and connecting rod assembly using the J 24086-B  (1).

  6. Object Number: 1241744  Size: SH
  7. Select a set of new piston rings.
  8. Measure the piston ring gap using a feeler gage. Refer to Engine Mechanical Specifications .
  9. Increase the piston ring gap by carefully filing off excess material if the piston ring gap is below specifications.

  10. Object Number: 1241745  Size: SH
  11. Measure the piston ring side clearance using a feeler gage. Refer to Engine Mechanical Specifications .
  12. If the piston ring is too thick, try another piston ring.
  13. If no piston ring can be found that fits to specifications, the piston ring may be ground to size with emery paper placed on a sheet of glass.

  14. Object Number: 1241746  Size: SH
  15. Install a piston oil ring, the expander, then the second piston oil ring to the bottom ring groove of the piston.
  16. Install the second compression ring to the middle ring groove of the piston.
  17. Install the top compression ring to the top ring groove of the piston.

  18. Object Number: 1241747  Size: SH

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

  19. Use a piston ring expander to install the piston rings. Do not expand the piston rings beyond the expansion necessary for installation.
  20. Stagger the piston oil rings (2), the oil ring rail gaps (3), the second compression ring (4), and the top compression ring in relation to the notch on the top of the piston (1).

  21. Object Number: 1241748  Size: SH
  22. Lubricate the cylinder wall and the piston rings with clean engine oil.
  23. Install the piston using a ring compressor and a wood handle. Guide the lower connecting rod end to prevent damaging the crankshaft journal.
  24. Install the connecting rod cap and the bearings. Refer to Crankshaft and Bearing Cleaning and Inspection .
  25. Notice: Refer to Fastener Notice in the Preface section.


    Object Number: 1241750  Size: SH
  26. Install the connecting rod cap bearing bolts.
  27. Tighten

        • Tighten the connecting rod bearing cap bolts to 25 N·m (18 lb ft).
        • Using the J 45059 or the KM-470-B  (1), tighten 1 turn of 30 degrees plus 15 degrees.

    Object Number: 1241699  Size: SH
  28. Install the oil pump/pickup tube.
  29. Install the oil pump/pickup tube bolts.
  30. Tighten
    Tighten the oil pump/pickup tube and support bracket bolts to 10 N·m (89 lb in).

  31. Install the oil pan. Refer to Oil Pan Replacement .
  32. Install the cylinder head with the intake manifold and the exhaust manifold attached. Refer to Cylinder Head Replacement .