I figured I would add to this thread.
I recently installed a Spartan into a 94 Sidekick rear diff. Removed sidegear thrust washers as instructed. Each side had a thin one and a thicker one. Assembly went easy and didn't require shaving the cross pin block as I was warned would probably be needed. Once diff was assembled, it was verified that the internals weren't pinched and all looked ok. Test drive showed the rear end to act like a spool and make nasty clunking / snapping noises going straight and turning. (FYI: I've had a lockrights front & rear in my samurai for over 10 years so I know how these lockers sound and feel)
So, we broke it all down again. Suggestions from the experts varied from it being too loose to it being too tight. We banked on it being to loose on the outside of the sidegears (externally) and too tight between the locker gears / crosspins (internally). So we replaced the thicker thrust washers onto the sidegears. This required grinding the cross pin block to allow the crosspins to install smoothly and result in no binding. Once diff was all together, we again verified nothing was pinched and that the locker looked & felt good. Put it back together and went for a spin. It now unlocks but gives a pretty violent snap / pop on each tooth. I assume the shimming is still incorrect, but we got it closer to being correct by doing what we did. I really don't want to tear it down again without having a good game plan. Any suggestions out there?
Thanks...