Charging unit issues: Broken brush unit

Hey everyone! Still trying to fix the issues with my XJ 550 1981. Has anyone ever had issues with the brush mounting plate breaking? After installing the last one, having that one break too, I'm starting to think that it's not user-installation error. I have a hunch it's the rotor, but I'm not really sure. Anyone have any ideas before I take it to a shop and have them fix the charging unit?

 

Yes! Have you verified that you have all of the screws and washers in there correct places (bounce it against the parts breakdown)? A missing washer could create a stress point.
I cannot for the life of me figure out how to break one of those plates. Are you overtorquing the mounting screws?
I'm only a 40 minute ride north, I would be happy to pop down and have a look. I also have a torque screwdriver (close cousin to the torque wrench). We could also do a runout on your rotor if it appears that your rotor is wobbling. But it should only get into this condition if it has been dropped. Possible?
Let me know if I may be of assistance.

 

Heeyyy...this guy's good...anything preventing it from tightening down evenly could crack it, but so could an out-of-round rotor. The nature of the "break" might provide a clue...