Micrometer Method For Crankshaft Bearings
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- Measure the crankshaft main journal diameter with a micrometer in several places along the length approximately 90 degrees apart, minimum of 4 places, and average the measurements.
- Determine taper and the out-of-round. See CRANKSHAFT table.
- Install NEW crankshaft bearings into crankshaft bearing caps and engine block.
- Install crankshaft bearing caps and crankshaft bearing cap bolts and studs. Tighten crankshaft bearing cap inner bolts to specification. See TORQUE SPECIFICATIONS . Tighten the crankshaft bearing cap outer studs to specification. Using a Torque Angle Meter (J-36660-A) , tighten crankshaft bearing cap inner bolts an additional 90 degrees. Using the torque angle meter, tighten the crankshaft bearing cap outer studs an additional 80 degrees.
- Measure crankshaft bearing Inside Diameter (ID) using an inside micrometer. Measure at a minimum of 4 places and average the measurements.
- In order to determine the crankshaft bearing clearance, subtract the crankshaft journal diameter from the crankshaft bearing ID.
- Compare crankshaft bearing clearance to specifications. See CRANKSHAFT table.
- If crankshaft bearing clearances exceeds specifications, install undersize crankshaft bearings to achieve the correct clearance.
- Measure new crankshaft bearing inside diameter using an inside micrometer.
- Replace crankshaft if the proper clearances cannot be obtained with standard size bearings.