Piston and Connecting Rod Disassemble

1. Follow the base engine noise diagnostic information found in the Engine Repair Section of the Service Manual.

2. Prior to piston/connecting rod removal, mark or identify the piston/connecting rod assembly, and its orientation to the front of the engine, before removal.

3. Remove the pistons from engine cylinders 1-4 following instructions found in the Engine Repair Section of the Service Manual.





Important:
^ *Provided for illustration purposes only. Actual orientation of scuffing on cylinder wall may be different.
^ Honing of cylinder walls is not recommended for this procedure. If cylinder walls are badly scored, replace the engine assembly.

4. Reference the previous illustrations. Inspect all cylinder walls and piston skirts for scoring. Excessive scoring would be defined by marks which may be felt by a fingernail that is passed over them. Blemishes (discoloration) that appear in the cylinder wall finish, which are not detectable by a fingernail, are not considered cylinder wall/piston skirt defects.

5. The following engine piston part numbers should be utilized in this repair:

Part number 12564009 - LG8 3.1 Liter Service Piston.

Notice:
A rod kiln MUST be used during assembly of the connecting rod to the piston. If a connecting rod kiln is not available, seek the assistance of a reputable machine shop with a kiln. Under NO circumstances should an acetylene torch or other uncontrolled heating device be used on connecting rods, as permanent damage to the connecting rod may result.

6. The following steps are provided to assist in the successful replacement of the piston assemblies.

Important:
It is not necessary to replace the piston rings, unless they were damaged during the repair process. If the piston rings are to be reused, mark or identify the location/order of the rings as they correspond to location on the piston being serviced. Refer to ring gap placement instructions found in the Engine Repair Section of the Service Manual.





7. Using piston ring pliers, remove the piston rings from the piston.





8. Install the J 24086-310 fork insert into the J 24086-10 fixture support assembly.

9. Install the piston and connecting rod assembly onto the J 24086-10.





10. Install the J 24086-107 adapter onto the piston pin, and install the J 24086-88A through the J 24086-10 and onto the J 24086-107.

Important:
The piston and pin are a matched set and are not to be serviced separately.





11. Press the piston pin from the piston and connecting rod assembly.