Inspection

PROCEDURE

1. Inspect the crankshaft main and connecting rod journals for wear and scoring. Check the crankshaft oil passages for blockage.

2. Using a micrometer, measure the diameters of the crankshaft journals in two diametrically opposite directions. If there is scoring or out-of-round, regrind the crankshaft. Regrind the crankshaft journals only to the next undersize. If the crankshaft is ground to the +0.50 mm repair size, heat-treat the shaft to increase its durability.

Crankshaft main journal diameter: 50 mm

Connecting rod journal diameter: 45 mm

Crankshaft journal out-of-round and taper: 0.01 mm maximum

3. Inspect the connecting rod and main bearing inserts for local corrosion, wear and other damage. Replace the inserts if necessary.
Measuring Main and Connecting Rod Bearing Clearance
To measure the main and connecting rod bearing clearance, measure the crankshaft journal diameters and the corresponding inside diameters of the bearings.

Clearance is the difference between the inside diameter of the bearing and the corresponding crankshaft journal diameter.

Main bearing clearance, Nos. 1, 2, 4 and 5 crankshaft: 0.028–0.045 mm

Main bearing clearance, No. 3 crankshaft: 0.034–0.520 mm

Crankshaft connecting rod bearing clearance: 0.024–0.042 mm