Our shaft cover got old and finally started spinning in the auxillary holder for slicing discs. Resultant heat sort of welded old plastic to steel shaft. I removed the old plastic by cutting off and then had to drill into plastic remaining between the shaft and the brass ring at the base of the old shaft cover. A small amount of plastic solvent over time may have done the same thing. New replacement shaft cover then can be pressed/hammered on.
Kris Castle, January 2008