Hey, I just installed my first lift on my XJ.

3 inch rough country add a leaf system.

All is good except my passenger right knocks and vibrates like a ****.

At 30 I get a slight vibration then at 35 it goes away, returns at 55 and vibrates and knocks decelerating all the way to 0.

What the hell!!

 

need to do a alignment right away! i have the same lift. Cherokees are picky if something is out of spec

 

Get an alignment for sure. You will also want to get a transfer case drop kit or a SYE, sounds like you have driveshaft vibes. Most lifted Cherokees do. I had vibes for years until I put in new ujoints and a tcase drop kit.

 

sounds driveshaft related.

 

Is it doing any damage?? I'm going to get an alignment but in the meantime how bad is it to drive

 

Hard for me to diagnose it without actually driving it and being there, but your u joints in the rear driveshaft could have been on their way out and once you lifted it they are operating at angles outside of their usual wear pattern. Replacing the u joints may fix it. But if they don't you might be able to drop the t-case to help alleviate the vibrations ( though i would never run one) The best fix would be an sye and dual cardan shaft (if it truly is driveline issues you are experiencing)

 

I see an adjustable track bar and SYE in your future.

 

pull your front driveshaft drive it around at speeds where vibes occur. If you vibes are gone then its either your front u joints or your pinion angle or a combination of both. If vibes are still there re-install front shaft then remove rear driveshaft, place tc in 4hi now go drive around again. If vibes are gone then its either you rear u joints or tc/pinion angles. fixes are mentioned in above posts. But if the vibes are still there then its something else. Didnt spend a dime and now you know what your problem is or isnt.

 

Only a 2wd so it's gotta be the rear!=p

 

How much are u joints and how easy are they to put in? I really don't know much all.

 

I guess that test is out lol.get the Spicer brand u joints think they are anywhere from $15-25 I don't remember how much mine were when I ordered them.

 

Get a SYE, get a CV shaft that's balanced, and shim the rear axle using degree shims after measuring your pinion angle.

 

Alright guess I'm going for u joints and shims thanks guys
In the meantime is it driveable it's my DD

 

If you just have vibes, you will be fine driving it. If it's out of control shaking then, no don't drive it. But for sure address it, tcase drop kits are cheap and easy to do. But if you want an actual fix for the problem get a SYE. I'm too cheap to do a SYE, so I just went with the drop kit. It worked for me, but it may not work for your XJ.