Piston Pin: Service and Repair

DISASSEMBLY





1. Apply engine oil to the piston pin snap rings (A) and turn them in the ring grooves until the end gaps are lined up with the cutouts in the piston pin bores (B).

NOTE: Take care not to damage the ring grooves.





2. Remove both snap rings (A). Start at the cutout in the piston pin bore. Remove the snap rings carefully so they do not go flying or get lost. Wear eve protection.





3. Heat the piston and connecting rod assembly to approximately 158°F (70°C), then remove the piston pin.

INSPECTION

NOTE: Inspect the piston, piston pin and connecting rod when they are at room temperature.





1. Measure the diameter of the piston pin.

Piston Pin Diameter:
Standard (New): 21.962-21.965 mm (0.8646-0.8648 inch)
Service Limit: 21.954 mm (0.8643 inch)





2. Zero the dial indicator to the piston pin diameter.





3. Check the difference between the piston pin diameter and piston pin hole diameter in the piston.

Piston Pin-to-Piston Clearance:
Standard (New): -0.0050 to +0.0010 mm (-0.00020 to +0.0004 inch)
Service Limit: 0.004 mm (0.0002 inch)





4. Measure the piston pin-to-connecting rod clearance.

Piston Pin-to-Connecting Rod Clearance:
Standard (New): 0.005-0.014 mm (0.0002-0.0006 inch)
Service Limit: 0.019 mm (0.0007 inch)

REASSEMBLY





1. Install a piston Din snap ring (A).
2. Coat the piston pin bore in the piston, the bore in the connecting rod, and the piston pin with engine oil.





3. Heat the piston to approximately 158°F (70°C).








4. Install the piston pin (A). Assemble the piston (B) and connecting rod (C) with the embossed marks (D) on the same side.
5. Install the remaining snap ring.