SD-70 - AZL There are some other issues with the AZL SD's that Robert Ray discovered. They drive the axle worm gear through a flexible plastic tube. This is not always perfectly 'slid' on the motor shaft or worm gear, creating a sort of binding. More significant it seems is the worm gear bushings are swivelling balls with through holes. These are held in place by a black plastic block. The block has a tapered shape and fits tight into the motor halves. It appears that this compresses enough to hold the brass bushing too tight so it does not freely move with the gear flexing. Jeff Merrill reports that he has filed them down (removed the taper) so that it fits more freely in the motor halves. He got about a 30% speed improvement with a bit less current demand. Rob got at least a 50% improvement.