I think this thread may be annoying some people, and I'm afraid I'm here to make it worse. The motor has started working for no discernible reason. It starts with the belt attached, and I even started it while applying pressure to the pulley to make the motor work harder.
I have done nothing to the motor since the last time it popped the GFCI, except for adding oil to the cups. I don't see how this could matter.
The bearing on the wheel end is no good. I can confirm that. It gets too hot to hold onto after a few minutes. The other bearing stays cool. I don't know how bad things are. I have not measured the RPM's yet to see if the bearings are slowing the motor down.
I had never seen this type of motor before, so I thought it was pretty fancy. I have since learned that 1/4-HP 1725-RPM motors with rubber mounts are very common. TEFC jobs cost around twice as much, however, so I'm glad I don't have to buy one right now.
I have been trying to open the spindle with a pin wrench, but it's not going well. The slots are getting chewed up. I drilled two new holes for the pins. I could get a better grip on the nut if the inner spanner nut were out, so I'm going to see if I can remove it. I am hoping there is no shoulder trapping it under the big nut. I'm off to the auto parts store to buy two 1/2-20 nuts so I can grind them down and turn them into jam nuts for immobilizing the spindle.