The starter I installed on my TO 20 whined with a thin metal to metal sound. I jack-legged about 0.40 inch of shims against the housing, and the whine stopped. Is this a sound procedure?
I have never heard of having to shim Ferguson starters. I’m sure it has something to do with the quality of the reproduction. It is not unusual to have to shim starters on GM cars and trucks, and special shims made for this purpose usually come with rebuilt starters. Ferguson did not make shims for their starters because they were never needed. If the shims solve the problem temporarily I don’t think they will do any harm other than providing a place for dirt to get into the clutch/flywheel housing. Maybe once the starter has been used a while and tolerances increase, the shims can be removed?