Piston, Connecting Rod, and Bearing Installation

Tools Required 

• J 5239 Connecting Rod Guide
• J 8037 Piston Ring Compressor
• J 36660-A Torque Angle Meter

  Important  : The piston and cylinder bore have been measured and the bore has been sized for the proper clearance. Install the piston and connecting rod assembly into the proper cylinder bore. The piston alignment mark MUST face the front of the engine block.

1. Lightly lubricate the following components with clean engine oil:
   • The piston
   • The piston rings
   • The cylinder bore
   • The bearing surfaces
Fig 1: Installing Piston, Rings, Cylinder Bore & Bearing Surfaces
Courtesy of GENERAL MOTORS CORP.
2. Stagger the oil control ring end gaps a minimum of 90 degrees.
3. Stagger the compression ring end gaps a minimum of 25 mm (1.0 in).
4. Install the J 8037 onto the piston and compress the piston rings.

   Important  : The piston alignment mark MUST be facing the front of the engine block.

5. Install the J 5239 on the connecting rod bolts.
   Fig 2: Installing J 5239

   Courtesy of GENERAL MOTORS CORP.
6. Install the piston and connecting rod assembly into the proper cylinder bore.
7. Hold the piston ring compressor firmly against the engine block. Using a wooden hammer handle, lightly tap the top of the piston until all of the piston rings enter the cylinder bore.
Fig 3: Installing Piston & Connecting Rod Assembly
Courtesy of GENERAL MOTORS CORP.
8. Guide the connecting rod end onto the crankshaft journal.
   CAUTION: Refer to FASTENER NOTICE in Cautions and Notices.
9. Install the bearing, cap, and nuts.
   Fig 4: Installing Bearing, Cap & Nuts

   Courtesy of GENERAL MOTORS CORP.

   Tighten 

   1. 9.1. Tighten the connecting rod bearing cap nuts a first pass to 20 N.m (15 lb ft).
   2. 9.2. Tighten the connecting rod bearing cap nuts a second pass to 75 degrees using the J 36660-A.
10. With the pistons and connecting rods installed, use a soft faced mallet and lightly tap each connecting rod assembly parallel to the crankpin to make sure that the rods have side clearance.
11. Measure the connecting rod side clearance using a feeler gage or dial indicator. Connecting rod side clearance should be within 0.18-0.44 mm (0.007-0.017 in).

Fig 5: Measuring Connecting Rod Side Clearance

Courtesy of GENERAL MOTORS CORP.