I have plans to beef it up quit a bit inline with the torque arm idea and to add a nynut to lock the axle nut once it is tightened or to use safety lock wire or something like that to keep the nut from backing up.
Here is what I found under the cover. I try to avoid puddles but what you see may be the result of hitting one or two that were less that an inch deep and less than two feet across. The magnets are most susceptible since that is why they are plated. Once the corrosion (aluminum oxide) and rust (iron oxide) get built up they can fill the air gap between the stator teeth and the rotor magnets. This is what was causing the wheel to put so much pressure on the axle that it wedged the hanger slots apart. At speed its hard to feel but from dead stop you sometimes can not even turn the wheel without an extraordinary amount of force.
The sensors still work and the wiring does not appear to be shorted but the jacket is stiff which is typical of too much heat. Also the high temp (380f/193c) hot melt glue I used to insulate the sensors has melted in runs typical of what you would expect after the motor was stopped and air was no longer cooling.
However, there is another possibility that I should probably mention. That possibility is a warped rotor or maybe even a warped stator.
...a good cleaning is next followed by some anti-corrosion measures.