SMU - Revised Piston Pin Removal/Installation Procedures

This bulletin is being revised to update the models information. Please discard Corporate Number 01-06-01-002 (Section 06-Engines).

This bulletin is being issued to revise the piston and rod assembly removal/installation procedures in the Engine Section of the Service Manual.

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

Tools Required

Piston and Connecting Rod Disassemble

Important: 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.

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




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.

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.

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



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



4. Install the piston and connecting rod assembly onto the J 24086-10.
5. 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.

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

Piston and Connecting Rod Assemble

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



2. Adjust the J 24086-9 installation pin to the following setting: G-7.

Caution: Avoid contact with HOT components. Wear safety glasses and protective heat gloves to avoid personal injury!

Notice: Applying excessive heat to the connecting rod may damage or distort the connecting rod or piston. Connecting rod temperatures should not exceed 320°C (612°F).

3. Using a connecting rod kiln, heat the piston pin end of the connecting rod to 320°C (612°F).



4. Refer to the above illustration. Assemble the piston, the connecting rod, and the J 24086-6A adapter as shown. Insert the piston and connecting rod assembly into the J 24086-10 fixture support assembly.




Notice: After the J 24086-9 installation pin bottoms on the J 24086-10 fixture support assembly, do not exceed a pressure of 35,000 kPa (5,000 psi), or damage to the connecting rod press may result.

5. Refer to the above illustration. Install the J 24086-105 (2) onto the piston pin. Position the J 24086-9 (1) though the J 24086-10 fixture support assembly and onto the J 24086-105 (2).
6. Press the J 24086-9 (1) installation pin until it bottoms on the J 24086-10 fixture support assembly.
7. Reinstall the piston rings onto the new piston. Refer to the Engine Repair Section of the Service Manual for proper ring gap positioning.



8. Refer to the above illustration. Install the assembled piston and rod assembly into the engine. Verify that the directional arrows on the top of the piston point to the front of the engine.
9. Follow the remaining engine assembly instructions found in the Engine Mechanical Section of the Service Manual.