[ajgriff]

Probably not relevant now but if the Variac is like the smaller Lyons Zenith designs there aren't really any bearings as such. The aluminium control shaft simply rotates inside a tube made of a non-conductive fibrous material. It's possible of course that the shaft is now slightly bent as mentioned in an earlier post.

Alan

Additional Info: To be more accurate, the shaft and the fibrous tube are clamped together and the entire assembly rotates inside a central metal tube. I've just checked mine!