Larry and Doc, thanks for your replies.

Like I said, I have no history on this car. Without a doubt the rear wheels turn in the SAME direction when I have the car off the ground. If the direction of the wheels turning is the litmus test that proves one way or another the presence of a LSD, I would have to say there is a LSD in my car regardless of whether LSD's were or were not supplied as original equipment.

I've never owned a LSD and know very little about how they work or what lubricants they use. Would I be right to assume that putting straight gear oil in a LSD could cause damage to the LSD, but putting the correct LSD lubricants into an open diff would probably cause little damage? I'm just afraid that without KNOWING which diff. I have I could do more bad than good by changing the oil with the wrong lube.

If we assume a LSD is in the car, Larry are you saying I can use regular or synthetic (which I prefer) gear oil and then add a friction modifier. I have no baseline as to how much of this modifier to add. Where do I start? Enough to keep it from clicking? Is there something that is pre-mixed?

Lots of questions, sorry.

Bob