I bought my 1968 Dodge Charger project in August 2021 and today I removed the rear tire and pulled off the right rear drum and was stunned to see the shoes, springs and drum coated with thick oil/grease. Never seen anything like it. What would cause that? It is bad.

 

Is it gear lube?

 

I think so. Maybe a rear axle seal gave way a long time ago. I hope those aren't hard to replace.

 

Go online and watch a video. It's not hard to pull the axle on an 8-3/4 if that is what you have. It could have been leaking brake fluid that was never attended to also. Check the master cylinder and see if it's leaking.