Assemble Procedure

1. Courtesy of GENERAL MOTORS COMPANY

   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.
   • The piston is model dependent and may not appear exactly as shown.

   Lubricate the piston pin bores in the piston (1) and the connecting rod (2) with clean engine oil. Adhesives, Fluids, Lubricants, and Sealers

2. Courtesy of GENERAL MOTORS COMPANY

   Assemble the piston (3) and piston pin (2) to the connecting rod (4). 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 (1) into the piston (3) and the connecting rod (4).
NOTE:

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

5. Install NEW piston pin retainers (1) using the EN-46745  Piston Pin Clip Remover/Installer (5). Align the EN-46745  Piston Pin Clip Remover/Installer (5) to the notch in the piston.

6. Courtesy of GENERAL MOTORS COMPANY

   Ensure that the piston pin retainers (1) are fully seated in their grooves.

7. Repeat these procedures for the remaining pistons.

Piston Ring Installation Procedure

1. Courtesy of GENERAL MOTORS COMPANY

   Properly orient the piston oil ring rail spacer (1) expander as shown before installation. The ends of the piston oil ring rail spacer must be facing toward the top of the piston.

2. Courtesy of GENERAL MOTORS COMPANY

   The piston compression upper ring and piston compression lower rings have either a dimple (1) or the word "TOP" (2) on the top side of the ring. The rings should be installed so that either of these marks are facing the top of the piston.

3. Courtesy of GENERAL MOTORS COMPANY

   Using a piston ring expander, install the piston oil ring rail assembly using the following procedure:

   1. Install the piston oil ring rail (4). Expand the rings only enough to clear the piston diameter. Overexpanding the piston rings will distort or crack the rings.
   2. Install the piston oil ring rail spacer (3).
   3. Install the piston oil ring rail (4). Expand the rings only enough to clear the piston diameter. Overexpanding the piston rings will distort or crack the rings.
NOTE:

The piston compression lower ring (2) is thicker and will not fit in the piston compression upper ring (1) position.

4. Install the piston compression lower ring (2) onto the piston with the mark facing the top of the piston.
5. Install the piston compression upper ring (1) onto the piston with the mark facing the top of the piston, if required.

6. Courtesy of GENERAL MOTORS COMPANY

   Once the rings are installed, set the ring gaps for the piston rings as follows. Use the piston location arrow for reference.

   1. Piston Compression Lower Ring (1) 30 degrees
   2. Piston Compression Upper Ring (2) 30 degrees
   3. Piston Oil Ring Rail- Upper (3)
   4. Piston Oil Ring Rail Spacer (4)
   5. Piston Oil Ring Rail- Lower (5)

Connecting Rod Bearing Installation Procedure

1. Courtesy of GENERAL MOTORS COMPANY

   NOTE:

   If the connecting rod bearings have been used in a running engine, you must replace them with NEW connecting rod bearings for reassembly.

   Clean the connecting rod (2) 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 bearing (1) 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-41556  Connecting Rod Guide (3) into the connecting rod bolt holes.

5. Courtesy of GENERAL MOTORS COMPANY

   Install NEW lower connecting rod bearing (1) into position in the connecting rod cap (2). Roll the bearing into position so that the lock tang engages the alignment slot. The bearings must fit flush with the connecting rod cap.