Bearing Clearance Measuring Procedures

The crankshaft bearings are of the precision insert type and do not use shims for adjustment. If the clearances are excessive, then new upper and lower crankshaft bearings will be required. The service crankshaft bearings are available in the standard size and an undersize.
The selective fitting of the crankshaft bearings are necessary in production in order to obtain close tolerances. For this reason, in one journal bore you may use one-half of a standard crankshaft bearing with one-half of a undersize crankshaft bearing.

Important: Do not use the plastic gauge method to measure connecting rod bearing clearances. The plastic gauge method for measuring connecting rod bearing clearances will result in unreliable measurements. Use only the micrometer method to correctly determine the connecting rod bearing clearances.

In order to determine the correct replacement crankshaft bearing size, the crankshaft bearing clearance must be measured accurately. Either the micrometer or plastic gauge method may be used; however, the micrometer method gives more reliable results and is preferred.