Problem du Jour: Stiff Tuner

[Winky Dink]

After the radio was completely assembled the tuning knob was slipping a bit in some spots. I snugged up the dial cord, but gang condenser kept getting harder to turn. Tried various lubricants including cleaning and regreasing the ball bearing joint. It just get worser and worser.
There are three bearing points, and I can't be sure which is the problem, but I suspect it's the ball bearings. The plates for sure don't bind.



It's clear that I don't know what I'm doing here, so does anyone have any suggestions before I screw it up further? I've got 3-in-One, SAE 20 and 30 oil, automotive lithium grease, white lithium grease and all-purpose spray lube.

Thanks,
Winky, the Eternal Novice.