Tracking Down a Worn Bearing Sound

I have a '99 1st Gen Ext Cab TRD. The truck has a worn bearing sound that I'm having trouble tracking down.

The sound is typical of a blown wheel bearing but doesn't sounds like it's coming from a specific area. I don't have any play in my front tires at all.

My rear tires have slight play when I leverage the tire at the 3 and 9 o'clock positions or if I grab the tire and pull/push straight out. I read some stuff suggesting that this is normal for the rear axle. I do have what appears to be a bad seal on the DS rear axle, oil leaking from behind the drum backing plate.

My drive shaft seems to be in pretty good shape. Front two u-joints are solid, I just replaced the center support bearing and followed the factory torque sequence for pre-loading the bearing on the shaft. The rear u-joint has very slight play (I think) could that cause a worn wheel bearing type sound (Wa-Wa-wa)?

I just replaced all fluids (both diffs, transmission, transfer) no change in the sound.

Ideas for other places to check or other ways to test my wheel bearings?

Could it be the rear u-joint? Could the leaking axel shaft seal be related?

 

The leaking seal contaminated the bearing. The gear oil broke down the grease in the bearing.

I'd start there. Pull the drum and listen for gravel sound using a screwdriver as a stethoscope.

 

The swerve method works for front bearings
Once weight transferred to one side, the failed bearing will be louder

as far as rear
Have buddy drive, u jump in the bed
Listen to both sides

to confirm rear…
Koditten’s method right on target/best way