- Clean the crankshaft with solvent and dry it. Clean the oil holes with a stiff brush and rinse them with solvent.
- Check the main and connecting rod journals for signs of wear, scratches, pits and cracks.
- Rub a copper plate several times on each neck. If traces of copper remain on the neck, it is too rough and needs to be re-ground.
- Remove all burrs from the oil holes on the shaft using a scraper or file.
- Check the shaft for cracks or other damage. In the workshop, use a flaw detector to check for hidden cracks.
- Using a micrometer, measure the diameter of the main and connecting rod journals of the shaft and compare the results with the technical data. By measuring the diameter at several points around the circumference, you can determine if there is ovality. By measuring the diameter at different ends of the neck, you can determine its taper. Both the taper and ovality of the necks should not exceed 0.002 mm.
- Measure the crankshaft runout by mounting the shaft on a prism; it should not exceed 0.10 mm. If the runout is greater, the crankshaft must be replaced.
Note: The runout value is the difference in indicator readings for one complete revolution.
- If the crankshaft journals are damaged, worn, have out-of-roundness or taper greater than the permissible limits, the shaft should be reground in a workshop. In this case, bearing shells of repair size should be used.
- Check the oil seal journals at both ends of the crankshaft for signs of wear or damage. If the seal has formed a groove on the neck, the new seal may leak. In some cases, the neck can be repaired by pressing a thin bushing into the groove. If repair is not possible, the crankshaft must be replaced.
- Check the connecting rod and main bearing shells.