RCA 7-ES-6J Motor Noise
 

I've been doing minor repairs on my RCA 4 speed suitcase record player, and have noticed a loud buzzing sound from my motor. It's been cleaned and lubricated multiple times, and I replaced the motor mounts for good measure, all of which did nothing to resolve this noise. Does anyone have any suggestions for what might be causing it? Bad bearings, maybe?

https://youtu.be/Sam2PYtG7uI

Is the shaft loose in the bearings at all? It should turn freely but have very little slop.
Are the windings tight on the core, if they are loose they could vibrate.

Only other thing I can think of is it's out of balance but that would be unusual.

It spins freely. It has a bit of up and down give but nothing I would consider that significant. The windings seem completely held in place.

I should also note that, despite all the noise, it runs at the correct speed.

If you stall the motor, does it still buzz?

If you stall the motor and it still buzzes, it could be lamination noise. It also could be a loose shading coil. That problem was most common in AC solenoids. :sigh:

I'll have to check the next time I get into it. That'll hopefully be this weekend.