When I turn the rear axle/either side by hand, I feel a "rumble"/gear meshing? How prominent should this be? Should it be rather smooth or some feeling of gear mesh?

 

it should not be. I can say though after going through my rear end, that it could just need bearings/rebuild. i.e the gears could be fine...could be.

it's not easy. but mine was real bad sounding. more like clunk clunk. do you hear any noise on either deceleration or acceleration?

 

No clunking....but a louder deep roar......I can't remember if the car had this sound originally, but it is noticeable now.

 

Sounds like a bearing to me, more likely to be gears if it is clunking. Regardless you need to pull the rear end apart

 

I think at this point I would suggest removing the rear axle shafts and checking each axle shaft bearing. This will require new axle seals and it wouldn't be a bad time to install new seals anyways. This will also require disassembly of the rear brakes. Will be good to inspect the shoe linings and wheel cylinders as well.

 

Agreed...I already have it stripped down to the backing plates...cylinders and linings are shot...4 more bolts and i can have the axels out by the way it looks...sounds like a good plan