did you happen to check the wheel after you pulled the axle to see if it was still binding?
to determine if the problem was actually in the wheel or in the differential is what i'm getting at.

IF it was still binding after pulling the axle you do have something wrong inside that brake assy. Look at the shoes, where they are sitting on the backing plate, look at the backing plate pads where the shoes sit for wear. Look at the adjuster and all the linkage associated with it. check the backing plate for looseness. Something is causing it to bind up.