John, to add to Todd's suggestions, here's a tip I got from Earl. Wrap the gearbox (and motor if it helps) with masking tape. This greatly helps keep the rubber strap wrench from slipping.

The first time you do this you think to yourself "You've got to be kidding, I'm going to break this thing!!!" I know I felt that way. But as long as you've loosened both of the set screws (Todd's correct, there are two) and the motor doesn't slip and fly across the room, you won't break it.

I've not used locktite when re-assembling either.

Keith B