Thanks. Good point, under load it could aggrevate a bearing.
It does do it all the time, but hits its best falsatto at certain narrow RPM ranges, loudest at approximately 1000 RPM. I pulled the belt off and spun it and yanked the armature back and forth - no slack, no noise.
and it has not changed in the last two years since I installed it.
I tried a new belt yesterday, but no change.
Maybe for the relatively low price of a regulator, I might try one.
Guess I could add the old one to my emergency spare collection in the trunk.


Thanks again for the inputs.

DG