GM Service Manual Online
For 1990-2009 cars only

Production standard 6.5L pistons are available in one grade size, identified by a J (naturally aspirated) or JT (turbocharged) ink or metal stamped on the top or bottom of the piston. Also available is a production oversize piston grade sizes for in-plant rework. Identified by an S (naturally aspirated) or ST (turbocharged) ink or metal stamped on the top or bottom of the piston.


    Object Number: 4977  Size: SH
  1. Remove the piston rings.

  2. Object Number: 66577  Size: SH
  3. Remove the connecting rod bearing inserts.
  4. Using a scribe with a hooked, rounded end, pry out the piston pin retainers.
  5. Remove the piston pin. The pin is a full-floating style and should slide from the piston. If the piston pin is to be reused, place it in a rack so that it may be reinstalled with the original connecting rod and cap.
  6. Remove the piston from the connecting rod.