Carefully inspect the crankshaft for signs of damage, and then measure the diameters of the main and connecting rod journals. The necks have three repair sizes, which increases the life of the crankshaft several times, provided that liners with repair sizes are installed.
Fix the crankshaft in the centers of the lathe and with the extreme necks on the prisms) and measure the shaft runout with an indicator. With a runout value of 0.06 mm or more, the shaft must be replaced or reground for repair liners.
Next, measure the clearance in the main and connecting rod bearings using the method described here. During the check of the connecting rod bearings, the nuts for fastening the connecting rod caps are tightened with a torque of 50 Nm - in the case of using old design connecting rod bolts; if the bolts of a new design - a torque of 30 Nm. Deformable bolts can be used to fasten the covers. The allowable clearance for the main bearing is 0.17 mm and for the connecting rod bearing is 0.12 mm. Bearings with a gap larger than indicated above should be replaced, and it should be taken into account whether the shaft journals have been previously ground.
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