Bearing Selection
Crankshaft Main Bearing SelectionImportant: If crankshaft bearing failure is due to other than normal wear, investigate the cause. Inspect the crankshaft or connecting rod bearing bores.
1. Inspect the connecting rod bearing bores or crankshaft main bearing bores using the following procedure:
1.1. Tighten the bearing cap to specification.
1.2. Measure the bearing bore for taper and out-of-round.
1.3. No taper or out-of-round should exist.
2. Install the original crankshaft main bearing inserts on to the cylinder block and the lower crankcase assembly.
3. Carefully place the crankshaft on to the bearing inserts in the cylinder block.
4. Lay a piece of gaging plastic (1) across each crankshaft main journal.
5. Carefully place the lower crankcase assembly on to the cylinder block.
Important: Do not turn the crankshaft while measuring the bearing clearance.
Notice: Refer to Fastener Notice in Service Precautions.
6. Install the eight main bearing cap bolts.
Tighten the crankshaft main bearing cap bolts in the sequence shown, use three progressive steps to obtain 54 Nm (40 ft. lbs.)
Connecting Rod Clearing Selection
1. The connecting rod bearings are of the precision insert type. The connecting rod bearings are available in standard and 0.25 mm (0.0098 inch) undersize.
Important: If crankshaft bearing failure is due to other than normal wear, investigate the cause. Inspect the crankshaft or connecting rod bearing bores.
2. Inspect the connecting rod bearing bores or crankshaft main bearing bores using the following procedure:
2.1. Tighten the bearing cap to specification.
2.2. Measure the bearing bore for taper and out-of-round.
2.3. No taper or out-of-round should exist.
Important: The crankshaft and the main bearing caps must be installed and properly torqued before measuring the connecting rod clearances.
3. Starting with the number one connecting rod (2), remove the connecting rod cap nuts.
4. Carefully remove the connecting rod bearing cap.
5. Lay a piece of gaging plastic (1) across the crankshaft number one connecting rod journal.
6. Carefully place the connecting rod cap onto the connecting rod.
Important: Do not turn the crankshaft while measuring the bearing clearance.
7. Install the two connecting rod bearing cap nuts.
Tighten the connecting rod bearing cap bolts to 35 Nm (26 ft. lbs.).
8. After reaching the proper torque, remove the two crankshaft connecting rod bearing cap nuts.
9. Carefully remove the connecting rod bearing cap from the connecting rod.
10. Measure the gaging plastic (1) at its widest point.
^ Standard Oil Clearance: 0.020 - 0.050 mm (0.0008 - 0.0019 inch)
^ Maximum Oil Clearance: 0.080 mm (0.0031 inch)
11. If bearing replacement is necessary, determine if a standard bearing or an undersized bearing is needed. The undersized bearing is identifiable by a stamping on the backside of the bearing.