I'm just curious. You say the pulley was coated with rubber. Does the rubber represent wear on the (presumably) rubber belt, or is the rubber coating part of the original build of the pulley itself? If the latter, what did you do to the rubber coating in the course of fixing the problem? Because I don't see how anything you did would directly address the problem "vibrating pulley". The measures you took would tend to counteract the problem but not directly fix it; the pulley should not be vibrating, obviously. Thx.