Best way to test an unmounted LSD?

[Earendil]

Why or why does searching for "how to test LSD" turn up zero results here at R3V?

Anyway... I might be picking up an LSD here pretty soon. The trick is that it's sitting on some dude's floor, so I have no way of verifying what the mileage is on it. Obviously confirming it's an LSD will be easy, but I'm wondering if there are any additional ways to verify the proper functionality of the LSD now that it's out of the car?

What should or shouldn't it sound like? I'm thinking when I last saw an LSD out of a car it had zero play between the two outputs, and the input.

Also, I need any tips or hints asap ;-)

[jlevie]

The rotating parts should feel smooth when turned and there should be no movement of the flanges. If up make up a round plate with a 1' or so nut welded to the center of the plate and holes to bolt up the plate to axel flange you can test the clutches for wear. That's done by holding the right flange (a bar bolted to the flange works) and using a torque wrench on the nut to find out how much torque is require to cause that flange to move. A clutch is really good condition will require 60ft-lb or a bit more. A good clutch with be 50-55ft-lb and a worn clutch will be well below that.

After that you just have to install the diff and see if it is noisy. Wear in the gears or bearings that opens up the clearance between the gears is what causes the whine. And that can only be determined by a teardown or running the diff.