New sound after lift install.

This is going to be hard to explain, but after a 3" rough country install on my 2000 XJ, I hear a low humming noise while driving at normal speeds. I still have stock tires, and put in a whole new leaf spring set.

Also, when I let off of the gas (again hard to explain) it almost sounds like a semis jake brake but at low low volume. I guess its like a vibration, but with out the vibration feel.

Does any of this sound normal, or do I have something to worry about?

Sorry for the weak description.

thanks.

A 2000 will have the low pinion front end, so the first thing I would do is pull the front drive shaft & see if the noise goes away. JIM.

I had this same thing happen to me, with the same leafs, I really think the shims used on the 3" springs in the RC kit are of the wrong size, it creates the wrong geometry for the driveline angle.

That noise you describe/hear is the driveshaft binding on itself, and it will eventually cause damage if you dont fix it.

You either need to get a SYE kit, lower your t-case, or remove the shims.

heres a pic of what im talking about from madxj.com
http://www.madxj.com/MADXJ/technical/technicalfiles/DKdsPhysics/images/drvangle_sm.jpg

the RC kit creates the angle found in the bottom pic, the second from the top is what most people use for XJ's

It sounds like it's time for a SYE. Mine made the same noise and I screwed around with the shims for a while. I couldn't get it to go away so I finally put in a SYE. Problem solved.

FLAGXJ said:

It sounds like it's time for a SYE. Mine made the same noise and I screwed around with the shims for a while. I couldn't get it to go away so I finally put in a SYE. Problem solved.

Click to expand...

X2

First, thanks for the advice, as there is tons of the same posts already I found out.

I did some research, and want to do a TC drop, about an inch. I dont really mind the clearance issues for a $20 fix right now. I will probably go with the SYE later though.

I know all jeeps are going to be different, and it might not work exactly, but will it prevent me from ruining my TC if I do that?

I also dont really care about quick disconnects for my sway bar, is there a really cheap alternative to make my sway bar links longer?

Since you have a LP D30,a TC drop may cause problems with the front driveshaft.At a minimum consider doing a H-n-T SYE.As far as the sway bar links,yes you can extend them,thats what I did!