Actually thats not too bad of an idea to check those out, I noticed on my passengers side the top trailing arm bushing on the differential seems to be worn and has made some clunking noises even in 2wd going over bumps but not too often (infact I forgot about it until you posted that!), maybe it is possible that due to the clunking & torque from the differential being in 4wd its amplifying that and I'm confusing it for binding? It definitely feels more like a binding noise but I should change the bushing anyway soon. Its odd because my GF said the noise sounded like it was coming from the drivers side and I thought it was coming from her side or at the least in the middle of the differential.

Certainly scares the living crap out of you because everything seems fine one moment then bang! time for new underwear.

 

That's probably your issue. I found my problem... Sheared the "stud" in the center of the CV joint in the front drive shaft. I'm done screwing with it, just ordered a complete brand new shaft with a lifetime warrantee from Advance Auto. USA made too! HeyYou, i agree, i just noticed it yesterday, I'm in the middle of this blizzard right now so repairs had to wait.

 

damn. how much does that cost?

 

I got it for $220 after tax w/ my employee discount.