Check the main and connecting rod journals for signs of wear, scratches, pits and cracks.
Rub a copper coin several times on each neck. If traces of copper remain on the neck, it is too rough and needs to be re-sanded.
Remove any burrs from the oil holes on the shaft using a scraper or file.
Check the shaft for cracks and other damage. Use a flaw detector in the workshop 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 whether there is an out-of-roundness. By measuring the diameter at different ends of the journal, you can determine its taper.
If the crankshaft journals are damaged, worn, have a non-roundness or taper greater than the permissible values, the shaft should be re-ground in a workshop. In this case, bearing liners of a repair size should be used.
Check the journals of the oil seals at both ends of the crankshaft for signs of wear or damage. If the oil seal has formed a groove in the journal, the new seal may leak. In some cases, the journal 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.
