Installation Procedure

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
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).
   Fig 1: Piston Components

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4. Install the J 41556  to the connecting rod.
5. Install the J 8037  onto the piston and compress the piston rings.
   IMPORTANT: The piston alignment mark MUST facing the front of the engine block.
6. Install the piston and connecting rod assembly into the proper cylinder bore.
   1. 6.1. 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.
   2. 6.2. Use the J 41556  to guide the connecting rod end onto the crankshaft journal.
   Fig 2: Tapping Piston Into Cylinder Bore

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7. Remove the J 41556  .
   Fig 3: J 41556

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8. Identify the type of connecting rod bolt.
   • The early design connecting rod bolt (1) can be identified by no collar/retaining sleeve on the bolt shank.
   • The later design connecting rod bolt (2) can be identified by a ferrule/retaining sleeve (3) on the bolt shank.
     Fig 4: Early & Later Connecting Rod Bolt Designs

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     NOTE: Refer to FASTENER NOTICE in Cautions and Notices.

     Important: 

   • When replacing connecting rod bolts, both bolts MUST be of the same design for each connecting rod assembly.

     The use of different design connecting rod bolts on the same connecting rod assembly may lead to uneven clamp loads and/or connecting rod bearing bore distortion.

   • Position the connecting rod cap onto the connecting rod properly.

     Align the flat side of the connecting rod cap with the flat side of the connecting rod.

   Fig 5: Bearing Cap, Piston & Bearings

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9. Install the bearing, cap, and bolts.

   Tighten 

   1. 9.1. Tighten the early design bolts a first pass evenly to 20 N.m (15 lb ft).
   2. 9.2. Tighten the early design bolts a final pass to 60 degrees using the J 36660-A  .
   3. 9.3. Tighten the later design bolts a first pass evenly to 20 N.m (15 lb ft).
   4. 9.4. Tighten the later design bolts a final pass to 75 degrees using the J 36660-A  .
10. Inspect the connecting rods for proper orientation onto the crankshaft journal.
11. 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.
12. Measure the connecting rod side clearance using a feeler gage or a dial indicator. Connecting rod side clearance should be within 0.11-0.51 mm (0.0043-0.02 in).
    Fig 6: Connecting Rod Proper Installation Position

    Courtesy of GENERAL MOTORS CORP.