Connecting Rod: Service and Repair

1. Replace connecting rod, if the large or small end thrust surface is damaged.





2. Check for bend or twist using a connecting rod aligner. Replace connecting rod if the bend or twist exceeds the limit. Limit of bend or twist per 100 mm (3.94 inch) in length: 0.10 mm (0.0039 inch)





3. Install connecting rod fitted with bearing to crankshaft and measure the side clearance (thrust clearance). Replace connecting rod if the side clearance exceeds the specified limit.
Connecting rod side clearance:
- Standard: 0.070 - 0.330 mm (0.0028 - 0.0130 inch)
- Limit: 0.4 mm (0.016 inch)

4. Inspect connecting rod bearing for scar, peeling, seizure, melting, wear, etc.





5. Measure the oil clearance on individual connecting rod bearings by means of plastigage. If any oil clearance is not within specification, replace the defective bearing with a new one of standard size or undersize as necessary.
Connecting rod oil clearance:
- Standard: 0.015 - 0.045 mm (0.0006 - 0.0018 inch)
- Limit: 0.05 mm (0.0020 inch)








6. Inspect bushing at connecting rod small end, and replace if worn or damaged. Also measure the piston pin clearance at the connecting rod small end.
Clearance between piston pin and bushing:
- Standard: 0 - 0.022 mm (0 - 0.0009 inch)
- Limit: 0.030 mm (0.0012 inch)





7. Replacement procedure is as follows.
a. Remove bushing from connecting rod with ST 499037100 connecting rod bushing remover and installer, or equivalent and press.
b. Press bushing with ST 499037100 connecting rod bushing remover and installer, or equivalent after applying oil on the periphery of bushing.
c. Make two 3 mm (0.12 inch) holes in bushing. Ream the inside of bushing.
d. After completion of reaming, clean bushing to remove chips.