Measuring Crankshaft Bearing Clearances - Micrometer Method

Measure the crankshaft journal diameter with a micrometer in several places, approximately 90 degrees apart. Average the measurements.
Determine the taper and out-of-round of the journal. Refer to ENGINE MECHANICAL SPECIFICATIONS .

Fig 1: Measuring Crankshaft Bearing Clearances
Courtesy of GENERAL MOTORS CORP.
Install the bearings into the engine block or connecting rod assembly.

Fig 2: Installing Bearings Into Engine Block Or Connecting Rod Assembly
Courtesy of GENERAL MOTORS CORP.
Install the bearing cap bolts and tighten to specifications. Refer to Fastener Tightening Specifications .

Fig 3: Installing Bearing Cap Bolts And Tighten To Specifications
Courtesy of GENERAL MOTORS CORP.
Measure the bearing inside diameter (ID) at two points 90 degrees apart. Average the measurements.
In order to determine the bearing clearance, subtract the average journal diameter from the average bearing inside diameter.
Compare the readings to specifications. Refer to ENGINE MECHANICAL SPECIFICATIONS .
Replace bearing halves as required to obtain the proper bearing clearances.