On my way home from work Monday I heard a clicking noise coming from the rear. I dropped it off at the shop and I'm sure its coming from the differential. I called today and they said its coming from the differential but they haven't had time to look at it and they weren't sure it it was shot or something they could fix.

I searched the forum and saw some people are switching to a Wavetrac. So I have the following questions.

Can a differential be repaired or will I likely have to replace it?
What can i expect a replacement to cost?
Anyone that upgraded to the Wavetrac willing to part with there stock diff?
What does the Wavetrac upgrade cost?

Thanks for your help