Main & Connecting Rod Bearings

With crankshaft removed, check runout with a dial indicator at number four journal. If runout exceeds 0.001" (0.03 mm), crankshaft must be replaced. Check journals for taper or out-of-round. If journals taper or are out-of-round more than 0.0004" (0.01 mm), crankshaft must be ground and undersize bearings installed.
Bearings are available in 0.010" (0.25 mm), 0.020" (0.50 mm), 0.030 (0.75 mm) and 0.040" (1.0 mm) undersize. Check both main and connecting rod bearing clearances using the Plastigage method. If clearance exceeds specifications, crankshaft must be ground for undersize bearings. Check connecting rod side clearance using a feeler gauge. If clearance exceeds 0.012" (0.3 mm), connecting rod must be replaced.