Turbo coupe peoeple: I have an 87 wiht the posi rear and it sometiems howls. Its usually at faster speeds like 55-60. I've checked the oil and it seems fine. Anyone else's howl? Is this normal?
Yo, its trac lok. And no hummin is not good.
Time to take a look.
have a clean bucket with a magnet down in it. use the magnet up in the diff as well.
85w90 would be a good replacement lub if you dont find anything.
The ptch of the individual gears are what needs looked at so get some info on that and then compare to what you see.
I cant help with suggestions on shims and where to put them, I have very little hands on experience on the rears but its just like anything else, stare and compare.