Hi - I have a 1968 Simpson fluid drive (similar to Speed Queens of same era) which has what seems to be an off centre tub. On spin, with nothing in it, it causes quite severe vibrations which causes the whole machine to 'walk' somewhat on the floor. I have had the tub/agitator shaft out for cleaning/minor repairs recently, but it all seemed to go back together OK. It's possible I've done something wrong, but not sure what. Any hints/suggestions welcomed.