70 Challenger with Dana & green bearings.
Started hearing some noise coming from rear of car. Sounds like a rhythmic rubbing/grinding type noise.
I can see signs of some gear lube leaking around axle seal.

Did the seal just go bad, or did the seal start leaking bcause the bearng gave out?

Lastly, what's the worst case scenario? Was hoping to make to the Garlits show this wknd, ok to drive?

Can't really hear sound with car in drive on Jack stands, might be my imagination, but rotating wheel seems "out of round"

If it's quiet on jackstands it could be your tires Does the noise change when you go around slight curves? I think you should be alright to go to the show.
If you need to get it changed it's a very easy job for any average mechanic and it can be done in less than 30 minutes.
Gus

I paid $130 for the harbor freight 12 ton press on sale. It already paid itself off after doing my own bearings that the guy wanted $120 for pressing off old bearings and retainers and pressing the new ones on. After doing it once it's an easy job with greens.

Jack up one side and pull the axle. R&R the bearing and slap it back together.

I had what sounded like a driveshaft noise. It was hard to tell if it was coming from the rear of the trans or the rear end. Turned out to be a bad rear wheel bearing. It was seeping gear oil and felt rough when spun by hand. I replace both sides and the sound was gone. This was only after a few thousand miles on the first set.

You notice one of your rear wheels sticking out about a foot in your rear view mirror.

Beat me to it.

On a more serious note, with it up on stands and tire mounted, you could likely feel some slop in the bearing if its going bad - either wobble or in and out. You might also feel some roughness as the wheel is turned by hand.

I've had this issue for a while...
'77 van 7 1/4 axle
I've re-greased the front bearings and changed out the stock tapered rear wheel bearings and the sound is still there.
Doesn't start up until things start warming up.
I am starting to think it's the pump in the trans.
I'm guessing the vibration goes through the drive shaft and gets amplified.

how old are the bearings??

I sure hope it's not the tranny. I have a 518 that was completely gone through and runs great.
The bearings are 7 years old with only 10-12k miles on them.

I do notice the sound more as the car warms up after being driven awhile.
But with the exhaust so loud it's hard to really pinpoint it.

When I installed green bearings on my car, I did not remove the thrust block because it did not seem to interfere. Went together fine, but there was just enough of a bind to eventually cook the bearings. Drove it for a long time before there was any symptoms. Got a grinding noise during a turn, no noise going straight.