Alright, so my roommate and I just installed a 3" lift on my 2001 xj. All is finally complete, and vibes aren't too bad. The only thing acting up is a thunking noise coming from the rear at any acceleration point. EVERY time I hit the gas (over 20 mph) I get the noise, which I'm guessing to be the slip yoke "thunking" in and out. Does anyone agree or have another idea? Is this a sign that the driveshaft is too short and I'll need an SYE? Any input would be great, thanks.

 

Could mean SYE, could mean U-joint bind?

 

U-joint bind? It's not a popping or clicking noise like I would usually associate with u-joints. Is that what you're referring to?

 

No.. U-joint bind is a common problem with lift and driveline angle together. Won't click but thunk, and should only happen at gear changes, kinda like slip yolk issues....

 

I'll look into it, thanks. The reason I was leaning towards the slip yoke is it sounds like it's pulling in and out at each acceleration, which makes sense. Plus I doubt the thing's been greased since '01, I haven't touched it in the 2+ years I've owned it

 

3in is kinda the max for a lift w/o an SYE. If your yolks worn out try replacing it till you can get an SYE, or maybe a new one will fix it. Did you do a tranny drop? That could help.

 

If I replace anything I'd go ahead an run a SYE and pick up a dc driveshaft from the junkyard. I may try a tc drop temporarily to see what that'll do also.