Check the main and connecting rod journals for signs of wear, scratches, pits and cracks.
Wipe several times with a copper coin on each neck. If traces of copper remain on the neck, it is too rough and needs to be sanded.
Remove any burrs from the oil holes on the shaft with 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 along the circumference, you can determine if there is any out-of-roundness. By measuring the diameter at different ends of the neck, you can determine its taper.
If the crankshaft journals are damaged, worn, out-of-round or tapered beyond the allowable values, the crankshaft should be re-sharpened at a workshop. In this case, oversized bearing shells should be used.
Check the seal journals at both ends of the crankshaft for signs of wear and damage. If a groove has formed on the neck from the stuffing box, the new stuffing box 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 bearings.