Got a 07 Sahara automatic with 70k miles on it and when I am in reverse, then place it in drive, I get a "clunk-clunk" sound. Jeep is totally stopped when I shift from R to D and it seems to do it when I accelerate which leaves me to think it may be a U joint going out but the rear doesnt have ujoints right? I changed the Diff fluid via the drain plug less than 3k miles ago. No other issues with the tranny that I hear or feel when shifting. Any thoughts? I gotta figure this out!!

 

Could it be the limited slip diff in the rear?

 

Sounds like something in your trans. It could the be valve body, torque converter, or other things inside the trans.

 

Double check all bolt tightness, spare tire carrier( some move just slightly and cause small noises.) Have a buddy shift it and you look under from a far..??