Piston, Connecting Rod, and Bearings Cleaning and Inspection (Connecting Rod and Bearings)

Important:  The powdered metal connecting rod and cap are machined for the proper clearances. The connecting rod and the cap must be used as an assembly with no repair or modifications to either mating surface.

Do not attempt to repair the connecting rod or the cap mating surfaces. If service is required, the connecting rod and the cap must be replaced as an assembly.

1. Clean the connecting rod and the cap in solvent.

   Important:  Replace the connecting rod if the bolt hole threads are damaged. Do not attempt to repair the bolt hole threads of the connecting rod.

2. Clean the connecting rod threaded bolts holes.
   CAUTION: Refer to SAFETY GLASSES CAUTION .
3. Dry the connecting rod with compressed air.
   Fig 1: View Of Connecting Rod Assembly

   Courtesy of GENERAL MOTORS CORP.
4. Inspect the connecting rod for the following:
   • Twisting
   • Nicks or gouging in the bearing bore
   • Damage to the bearing locating slots in the bearing bore
   • Proper fit of the connecting rod and the cap mating surfaces
   Fig 2: Inspecting Connecting Rod

   Courtesy of GENERAL MOTORS CORP.
5. Measure the connecting rod bearing bore for out-of-round. Refer to ENGINE MECHANICAL SPECIFICATIONS - LS1  or ENGINE MECHANICAL SPECIFICATIONS - LS6 .
   Fig 3: Measuring Connecting Rod Bearing Bore For Out-Of-Round

   Courtesy of GENERAL MOTORS CORP.
6. Inspect the connecting rod bearings for craters or pockets. Flattened sections on the bearing halves also indicate fatigue.
   Fig 4: Inspecting Connecting Rod Bearings For Craters Or Pockets

   Courtesy of GENERAL MOTORS CORP.
7. Inspect the connecting rod bearings for excessive scoring or discoloration.
8. Inspect the connecting rod bearings for dirt or debris imbedded into the bearing material.
   Fig 5: Inspecting Connecting Rod Bearings For Excessive Scoring Or Discoloration

   Courtesy of GENERAL MOTORS CORP.
9. Inspect the connecting rod bearings for improper seating indicated by bright, polished sections of the bearing.
   Fig 6: Inspecting Connecting Rod Bearings For Improper Seating

   Courtesy of GENERAL MOTORS CORP.