I just took apart a couple of motors to have a friend turn the comms, and I noticed something... Please look at these pix:
I don't know if you can tell by the pix, but the spacer on the spur gear end of the motor was pretty worn - very shiny. I noticed the same thing in the end of the motor can where this spacer rides.
I am trying to learn how to care for these motors and get the most life/performance out of them, (and I don't know what I am doing) - what does this tell me?