Piston and Connecting Rod Assemble

Special Tools 

EN-46745  Piston Pin Clip Remover/Installer

For equivalent regional tools, refer to Special Tools .

1. Courtesy of GENERAL MOTORS COMPANY

   NOTE:

   Install the piston onto the connecting rod with the arrow oriented toward the front of the engine.

   NOTE:

   The cast boss can be in either or both locations depending on displacement.

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

2. Courtesy of GENERAL MOTORS COMPANY

   The larger feature (1), at the split line located on one side of the connecting rod, must go to the front of the block.

3. Courtesy of GENERAL MOTORS COMPANY

   Assemble the connecting rod (4) and the piston (1).

4. Courtesy of GENERAL MOTORS COMPANY

   CAUTION:

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

   Use the following procedure to assemble the piston pin and the retainer:

   1. Coat the piston pin with oil.
   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.
   3. Install the connecting rod and the piston pin. Push the piston pin until it bottoms in the previously installed retainer.
   4. Install the second piston pin retainer, using EN-46745  installer (1).
   5. Ensure that the piston moves freely.

5. Courtesy of GENERAL MOTORS COMPANY

   CAUTION:

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

   NOTE:

   Ensure the 2. 5L upper compression ring (5) or 2. 8L upper compression ring (6) and lower compression ring (7) are orientated properly.

   Install the following components of the oil control ring assembly, bottom ring:

   1. The oil ring rail (4)
   2. The inner oil expander ring (3)
6. Install the lower compression ring, second ring (2). Place the manufacturer's mark facing up.
7. Install the upper compression ring, top ring (1). Place the manufacturer's mark facing up.
8. Install the piston rings so that the gaps are orientated as follows:
   • The upper compression ring (1) and lower compression ring (2) gaps should be 180 degrees from each other.
   • The inner oil expander ring (3) gap should be 180 degrees from the oil ring rail (4) gap.
   • The ASSEMBLED oil ring gaps should be 90 degrees from the compression ring gaps.