Hey Nuts, I just happened to be looking through the SM420 manual today, in antisapation of rebuilding mine. I think you meant .012" +/-.003"for the 2nd speed gear and .012" +/-.002" for the 3rd speeed gear.
That wouldn't be causing the noise that the Bee is hearing, a bad bearing is most likely the problem. And as George mentioned, it could be from the rollers, are you sure that they were all in there when you loaded them. It's possable that someone left one out previously. Loading them can be tricky if you haven't done it before and it wouldn't be the first time one got left out.
Denny Graham
Sandwich, IL
