Hey I've been having some diff problems that have seemed to have plagued my car for the last 4 years between me and the original owner. Its an 85 gls w/ 4 wheel disks and posi rear. I go to blip the throttle going left and it breaks loose like it should, but when I go right it just acts like an open diff and does nothing but hug the road. I'm quite sure that its not my sad attempts at drifting cause it goes good going left and there should be plenty of power to get it to break loose. I'm going to flush it and put in some nice lsd gear oil and see if that works but I'm wondering if it could be anything else. It also has a horrible howl at speed above 35ish(no speedo) but goes away when coasting but from what I've read it seems to be an FB thing. Any help?

 

The howl isn't an FB thing, it indicates a part is worn or misaligned. How does the right/left breaking loose do on wet pavement or hitting 2nd gear with throttle? Besides changing the diff fluid the only thing I can offer is check the rear discs for one that's hanging up or dragging.

 

When turning left in 2nd if I blip the throttle it will spin out, if I do it going right, it either just accelerates or understeers into a ditch lol. I think just the passanger side rear tire just sits there and spins. But when I launch it/brake stand/straight line stuff it roast both tires. And I figured out the howl is just the driveshaft ujoints actually.

 

https://www.rx7club.com/1st-generation-specific-1979-1985-18/wtf-rear-diff-sounsd-like-treadmill-set-its-highest-speed-932672/

Read up on the comments on this thread, its was helpful for me.