Piston, Connecting Rod, and Bearing Clean and Inspect

1. Measure the connecting rod side clearance. If the side clearance is greater than the maximum replace the connecting rod.
Standard Connecting Rod Side Clearance: 0.25-0.40 mm (0.0099-0.0157 inch)
Maximum Connecting Rod Side Clearance: 0.45 mm (0.0177 inch)

Caution: Wear safety glasses in order to avoid eye damage.

2. Clean the connecting rods in solvent and dry with compressed air.





3. Inspect the connecting rods for signs of being twisted, bent, bowed, nicked, or cracked.
Maximum Connecting Rod Bow: 0.05 mm (0.0020 inch)
Maximum Connecting Rod Twist 0.10 mm (0.0039 inch)
4. Inspect the connecting rods for scratches or abrasion on the rod bearing seating surface. If the connecting rod bores contain minor scratches or abrasions, clean the bores by sanding in a circular direction with a light emery paper. Do not scrape the rod or rod cap.
5. If the connecting rod bores cannot be cleaned by sanding, or if the bow or twist exceeds specifications, replace the connecting rod.





6. Measure the piston pin to connecting rod bore.
7. Measure the piston pin diameter in the area of connecting rod contact using an outside micrometer.
8. Measure the connecting rod piston pin bore using an inside micrometer.
9. Subtract the piston pin diameter from the piston pin bore diameter.
Piston Pin-to-Piston Pin Bore Clearance: 0.003-0.014 mm (0.0001-0.0005 inch)
Piston Pin Diameter: 20.997-21.000 mm (0.8267-0.8268 inch)
Piston Pin Bore Diameter: 21.003-21.011 mm (0.8269-0.8272 inch)
10. If there is excessive clearance replace the piston pin.
11. If there is still excessive clearance, replace the connecting rod.