GM Service Manual Online
For 1990-2009 cars only

Tools Required

    • J 29789 Piston Ring Compressor
    • J 36660-A Torque Angle Meter
    • J 43032 Crankshaft Rotation Socket

Piston and Connecting Rod Assembly Procedure

  1. Liberally lubricate the cylinder walls, piston rings and piston skirts with engine oil.

  2. Object Number: 576709  Size: SH

    Important: The connecting rod is nondirectional and may be assembled/reassembled to the piston in either direction.

  3. Select the correctly numbered piston/connecting rod assembly for the cylinder. An arrow showing proper piston orientation is located on the top of the piston.
  4. Important: If the connecting rod bearings have been used in a running engine, you must replace them with NEW connecting rod bearings for reassembly.

  5. Coat the crankshaft bearing journal and installed connecting rod bearings with GM crankshaft prelube GM P/N US 1052367, Canada 992869 or equivalent.
  6. Compress the piston rings using the J 29789 or equivalent.
  7. Important: Extreme care must be used when installing the piston and connecting rod in order to be sure the rod does not scrape or nick the cylinder bore or the crankshaft surfaces.

  8. Using both hands, slowly guide the piston and connecting rod assembly into the cylinder from the top and bottom of the cylinder. DO NOT allow the connecting rod to contact the cylinder wall.
  9. When the J 29789 contacts the deck surface, gently tap the piston into the cylinder using the handle end of a dead-blow hammer. Guide the connecting rod onto the crankshaft bearing journal while tapping the piston into the cylinder.

Connecting Rod Bearing Clearance Measurement Procedure

    Important: Connecting rod bearings that have been run in an engine should NEVER be reused.

  1. Before final assembly it is important to check the clearance of the new connecting rod bearings.
  2. Place a length of fresh, room temperature plastic gauging material all the way across the connecting rod bearing journal.

  3. Object Number: 576714  Size: SH
  4. Install the connecting rod end cap on its original connecting rod making sure the bearing lock tangs are aligned on the same side of the rod.

  5. Object Number: 576720  Size: SH

    Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

    Important: Reuse the old connecting rod bolts ONLY for measuring the connecting rod bearing clearance.

  6. Lubricate connecting rod bolts with engine oil and install in the connecting rod.
  7. Tighten
    Tighten the connecting rod bolts to 30 N·m (22 lb ft).

  8. Loosen the connecting rod bolts until the torque reading is zero.
  9. Re-tighten the connecting rod bolts.
  10. 6.1. First Pass

    Tighten
    Tighten the connecting rod bolts to 25 N·m (18 lb ft).

    6.2. Final Pass

    Tighten
    Tighten the connecting rod bolts an additional 110 degrees using the J 36660-A .

  11. Allow the assembly to sit for at least two minutes.

  12. Object Number: 576714  Size: SH
  13. Remove the connecting rod cap bolts.
  14. Remove the connecting rod cap.

  15. Object Number: 54236  Size: SH
  16. Determine the connecting rod bearing clearance by comparing the width of the flattened plastic gauging material at its widest point with the graduation on the gauging material container.
  17. Compare your measurements with the engine mechanical specifications. If the new bearings do not provide the proper crankshaft to bearing clearance, re-measure the crankshaft journals for the correct specified size and check to make sure you have the correct new bearings. If the crankshaft journals are incorrectly sized, replace the crankshaft. No crankshaft machining is permitted and undersized bearings are not available.
  18. Clean the plastic gauging material from the connecting rod bearing journals using a soft lint-free cloth.

Connecting Rod Final Assembly Procedure


    Object Number: 576714  Size: SH
  1. Install the connecting rod end cap on its original connecting rod making sure the bearing lock tangs are aligned on the same side of the rod.

  2. Object Number: 576720  Size: SH

    Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

    Important: DO NOT reuse the old connecting rod bolts.

  3. Lubricate the NEW connecting rod bolts with engine oil and install in the connecting rod.
  4. Tighten
    Tighten the NEW connecting rod bolts to 30 N·m (22 lb ft).

  5. Loosen the connecting rod bolts until the torque reading is zero.
  6. Re-tighten the connecting rod bolts.
  7. 4.1. First Pass

    Tighten
    Tighten the connecting rod bolts to 25 N·m (18 lb ft).

    4.2. Final Pass

    Tighten
    Tighten the connecting rod bolts an additional 110 degrees using the J 36660-A .


    Object Number: 287790  Size: SH
  8. During and after installation, check to make sure each piston is positioned properly in the correct cylinder. The locating arrow on the top of each piston (1) must be pointing toward the front of the engine.
  9. Repeat these procedures for the remaining piston/connecting rod assemblies using the J 43032 in order to rotate the crankshaft.