Len told me that in order to quieten the old belt drive, the belt had to be tightened so much that it was causing premature were on the drive and wheel bearings.
For the M3W overtightening the drive belt will often lead to it squealing. The factory spec tension is too high and a rule of thumb is to set the belt so you can twist the lower run by 45 - 90 degrees. Do this and it'll be quiet and the bevel box bearings will last.
My view is the Super3 belt is also set too tight and I know of a couple of owners who have slackened them off to a similar tension to the M3W and the belt noise disappeared.
If your Super3 is making a noise try slackening the belt to see if it cures it. If not you can always tighten it again.
