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 specifications. Connecting Rod Cap Torque
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 0.020 - 0.045 mm (0.0008 - 0.0018 inch). The limit is 0.070 mm (0.0028 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 connecting rod bearing grade No. 0 (black), crank pin journal grade No. 1 corresponds to rod bearing grade No. 1 (brown) and crank pin journal grade No. 2 corresponds to rod bearing grade No. 2 (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 0.030 mm (0.0012 inch).
4. If it exceeds the limit, replace the connecting rod assembly or connecting rod bushing and/or piston set with pin.