Crankshaft: Testing and Inspection

Clean the crankshaft and use a micrometer to measure the crankpins and journals.

Measurements should be taken at several points around the circumference.

Journal and crankpin out-of-round (ovality) should not exceed 0.05 mm (0.001970 inch).

When measuring out-of-round (ovality), use a micrometer positioned at two different places 90° from each other.

If the measurements are close to or in excess of this limit, the crankshaft must be ground down to the specified undersize.

Crankpins can be ground down to the first undersize using a straight grinding wheel.

If they are ground down beyond that, a grinding wheel capable of grinding radii must be used since undercutting only suffices to the first undersize.

Check that the shaft is straight to within 0.10 mm, using a dial gauge. Place the shaft with crankpins No. 1 and No. 5 in V-blocks, position a dial gauge on the middle crankpin and rotate the shaft.