VCCA Home Forums TECHNICAL - 1945 AND EARLIER 1929-1932 1931 generator

My generator on my 31 Cab has developed a squeal- squeak sound that I have traced to the brushes. If I lift all the brushes from the armature the noise stops. The armature turns smoothly
so not the bearings. I have cleaned the commutator with contact cleaner but no change.
Any suggestions?
Thanks
ThreeWindow

I wonder if the copper segments are worn uneven?

First thing I would check is to unhook the belt, so that you can slowly turn the pulley while keeping finger pressure on the brush, to see if you can feel the brush moving up and down just a tiny bit.

If the armature is good, meaning smooth and even segments, you won't feel the brush twitching.


other than that, see if the spring tension is still good on each brush. I can't see how a weak spring would allow some noise though.

You can try seating the brushes with a generator brush stone while the generator is turning. Otherwise you will probably have to turn and undercut the armature and install new brushes.

If your ammeter is oscillating at a higher generator speed then you have a weak brush spring or springs.

For your application the generator should be a Delco-Remy Model 943 J.