Connecting Rod Bearing: Testing and Inspection

BEARING CLEARANCE (AT CRANK END)
1. Install connecting rod bearing to connecting rod and cap.
2. Install connecting rod cap to connecting rod. Tighten bolts to 13.72 - 15.68 Nm (10.120 - 11.566 ft. lbs.). Then tighten another 35 - 40 degrees with an angle wrench or an additional 23 - 28 Nm (17 - 21 ft. lbs.).
3. Measure inner diameter "C" of each bearing.





4. Measure the outer diameter "Dp" of each crankshaft pin journal.
5. Calculate connecting rod bearing clearance. The connecting rod bearing clearance = C - Dp. The standard value is 0.014 - 0.039 mm (0.0006 - 0.0015 inch). The limit is 0.1 mm (0.004 inch).





6. If it exceeds the limit, replace bearing. If clearance cannot be adjusted within the standard of any bearing, grind the crankshaft journal and use undersized bearing. Refer to Crankshaft Main Bearing for bearing clearance information. If the crankshaft is replaced with a new one, select connecting rod bearings according to the following table. The connecting rod bearing grade numbers are punched in either Arabic or Roman numerals.

NOTE: For example, crank pin journal grade No. 0 corresponds to no identifying connecting rod bearing color, crank pin journal grade No. 1 corresponds to rod bearing color "brown" and crank pin journal grade No. 2 corresponds to rod bearing green.





BUSHING CLEARANCE (AT PISTON END)
1. Measure inner diameter "C" of bushing.





2. Measure outer diameter "Dp" of piston pin.
3. Calculate connecting rod bushing clearance. Connecting rod bushing clearance = C - Dp. The standard value is 0.005 - 0.017 mm (0.0002 - 0.0007 inch). The limit is 0.023 mm (0.0009 inch).
4. If it exceeds the limit, replace the connecting rod assembly or connecting rod bushing and/or piston set with pin.