Rear bearing failure. Rear bearing journal was undersized. Drawbar nut was seized to the shaft and needed to be machined off. Front bearings were contaminated. Taper was bellmouthed, tool only contacts in the rear of the taper.

Work done:

Grind plate grind rear shaft journal. Kiss grind taper. Manufacture new drawbar nut. Replace belleville washers on drawbar.Clean, inspect overall dimensions. Replace bearings, adjust preload, balance, assemble and break in. Final quality control inspection.