I'm trying to determine if the clutch-type LSD on a salvage '87 Turbo is any good (the car isn't a runner). It appears to have been leaking oil out the pinion seal, and it is very difficult to turn the axles, even with the calipers removed (to make sure brake drag/seizure wasn't the issue), with the gearshift in neutral. Initially when I turned it, I could only turn the right hub, and the left didn't turn at all. After a few turns, I was able to turn both axles, although it was still quite difficult, and the left side spun backwards from the right. I know there's some basic things that will identify a LSD from an open diff, but can't remember what the expected results should be.

My questions:
Should it be difficult to turn the hubs? And with both rears in the air and no drag from the brakes, how should the one not being turned move - ie, together, opposite direction, or not at all? Does it make a difference whether the tranmission is in gear?

Is any of this relevant to my trying to determine if the LSD has any life in it?

Bonus question - what would (should? - I'm assuming it's the original diff) the final drive ratio be on an 87 turbo?

thx in advance...

 

You would have to take it out, the brakes dragging and being rusty or worn or sticking wheel bearings could influence the outcome.

 

The answer to your bonus question is 4.10.

 

No matter what, if one wheel spins the opposite direction from the other the diff is worn out.