[TexasTechC6]

I have a 1999 XJ wiht a 8.25 and a 3" Black Mountain lift with a Skyjacker TC drop kit. I have noticed a clunk clunk clunk sound when I coast. The clunking is speed related. It happens in neutral as well. The clunking seems to be syncronized with either the tire rotation or the driveshaft rotation. I'm pretty certain it is not a tire rub. It goes away under acceleration. I just had the dealership do an oil change and check the level in the diff so it should have fluid. The truck has 105,000 miles on it. It seems to be getting progressively worse after this weekend's 1000 mile roadtrip. I do not know if it started before the lift or not...I just recently noticed it.....
Yes I did do a search, but I couldn't find anything definitive. What do you all think it is? I just bought the jeep within the last month and have dumped tons of money already. PLEASE HELP!
Thanks,
Newbie
PS I'm new to the Jeep thing..in fact this is the first non-GM that I have ever had.....

[balloo93]

Just for kicks, check the output slip yoke on the TC that attaches to the Driveshaft. If there are shint or wear spots on the ears of the yoke then your rear DS is making contact with the yoke.

You could also block the front wheels and put the rear end on jack stands. Remove the wheels/tires, put the trans in N and rotate the DS by hand to check if it's making contact.

Beyind that, check the Ujoint on the pinion yoke of the rear end.

[XJmallcruiser]

What ended up being your problem im having the same issue