Visual Inspection And Cleaning Procedure

Connecting Rod

1. Courtesy of GENERAL MOTORS COMPANY

   WARNING:

   Wear safety glasses in order to avoid eye damage.

   Clean the connecting rods (1) in solvent and dry with compressed air.

2. Inspect the connecting rod for the following:
   • Signs of being twisted, bent, nicked or cracked
   • Scratches or abrasion on the connecting rod bearing seating surfaces
3. If the connecting rod bores (2) contain minor scratches or abrasions, clean the bores in a circular direction with a light emery paper. Do NOT scrape the rod or rod cap.
4. If the beam of the rod is scratched or has other damage replace the connecting rod.

Piston

1. Courtesy of GENERAL MOTORS COMPANY

   NOTE:

   Some models may have pistons with an integral ring carrier design. It is important that all pistons match. When replacing pistons, ensure the correct matching pistons are used.

   Inspect the piston at the piston compression upper ring groove location (3). If the piston is entirely aluminum, it is a non-ring carrier piston (1). If the piston includes an integral steel insert, the piston is a ring carrier piston (2).

   1. When replacing non-ring carrier pistons, ensure a replacement non-ring carrier piston is available.
   2. When replacing ring carrier pistons, ensure a replacement ring carrier piston is used.
   3. If a matching piston is unavailable, replace all pistons.

2. Courtesy of GENERAL MOTORS COMPANY

   Clean the piston with a cleaning solvent. Do NOT wire brush any parts of the piston.

3. Clean the piston ring grooves.
4. Inspect the piston on the following:
   • Cracked ring lands, skirts or pin bosses
   • Ring grooves for nicks
   • Eroded areas on the top of the piston (1)
   • Scuffed or damaged skirts (2)
   • Worn piston pin bores (3)
5. If there is any excessive wear, replace the piston.
6. Measure the clearance between the piston pin and the piston bore, refer to Piston Pin To Connecting Rod Bore And Piston Bore Clearance.