Piston Pin Clearance

1. Use a micrometer to inspect the piston pin diameter in the X and Y directions at points A, B. C and D as shown.





2. Measure connecting rod pin end inner diameter.
3. Calculate piston pin press to connecting rod by subtracting pin diameter from connecting rod pin end inner diameter. Standard piston pin clearance is 0.015-0.040 mm (0.0006-0.0016 inch).
4. If the piston pin bore in the connecting rod is larger than specification, install a 0.025 mm (0.001 inch) oversize piston pin. Prefit the oversize piston pin to the piston pin bore by reaming or honing the piston to provide 0.007-0.013 mm (0.0003-0.0005 inch) clearance (light slip fit).