TXT48 Squeaky Rear Axle

[coreyx64]

Hello,
I have an EZGO TXT48 PDS Cart that has a rear axle that persistently squeaks. Gears and differential oil all are clean and spiffy, and appears to be in the hub/brake assembly. The squeak seemed to shift with the weight and force of the cart (turning left affects the right rear wheel, and vice versa) but now is just continuous on either side. My initial thought is worn out hubs, as the brakes seem to operate just fine when driving the cart. Bearings are also in good shape, oiled and spin freely with no slop.

Long story short, it's acting like the hubs (or axle) are out of round. The squeak occurs once per revolution, like clockwork (literally). At full speed, the noise is so frequent it just blurs into the noise of the motor, wind, etc. so not as noticeable. This cart is heavily used during the summer months (to the tune of 600-800 miles per season via the in-built GPS odometer), and is parked for the winter.

This is it's 2nd drive axle in less than 2 years (first had completely shredded gears with no teeth left, now this one with the irritating squeaks) and I'd rather not go for number 3 if I don't have to.

Any input or suggestions welcome. If I have to splurge on whatever new parts to rebuild what I have, I have no problem doing so, just want to be sure before spending $.

Thank you!