I have a rig that originally was lifted (albeit...with the factory components) 3". I bought a "tuff country" 3.5" and, just going off of the rear bumper, actually added 4 + inches....Had death wobble, fixed it with a drop Pitman arm...But have had and recently more pronounced rear diff/driveshaft noise. I changed the u-joints/straps...The noise, as far as I can tell, only comes after I let up on the gas pedal. The gears in the diff look brand new. I figure it's either the wheel bearings, although no north/south play, or the yoke bearing. I apologize for the long windedness, but could I need an S.Y.E., even though I technically only raised the rig .5"? I'm not trying to waste anyone's time...I replaced the u-joints when I first got it a little over a year and half ago. This is my daily driver, so I only have the weekends to work on it...Again, I really do appreciate any help/advice anyone can give me...

 

you can tell if you need an sye by looking at the rear drive shaft where it connects to the transfer case. When you get vibs or noise its from the u joint binding on itself and it marks the metal and you can see where it is happening. But i doubt that is your problem because when you need an sye its constant noise and it shakes the car to an extent. but Also you dont need one at only 3.5 inchs higher i would take a closer look at the noise maybe check the cat? something may be in it and when you let off the gas it can cause to knock around

 

hey i was wondering if you had fixed the problem with your transfer case yet. i have that same problem when i let off the gas pedal, i hear like a grinding noise coming from the transfer case or rear. i have a 99 xj with a 3" lift. the only thing i did was replace the fluids but that didnt help. i've had this problem for a while now and cant seem to figure it out. if you have any ideas please let me know.

 

Have you lowered your transfer case with a T-case lowering kit?

 

To answer your question honestly, I don't know. But...with a tid bit of research I might have a lead for you. How does this sound:

Deceleration vibration: Caused by the pinion being too low in relation to the transfer case output shaft. On leaf sprung vehicles, install axle shims to raise pinion accordingly.

And to cite my sources so that I don't get undue respect: http://rubiconexpress.com/Images/Pro...025/RE6025.pdf

Hope this helps.
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no i haven't but i tried researching them and saw mixed opinions. if it is an easy install i will try one, but if you think its a good idea i will consider it. i also heard some of the installs are different on different year xj's.

 

no i haven't but i tried researching them and saw mixed opinions. if it is an easy install i will try one, but if you think its a good idea i will consider it. i also heard some of the installs are different on different year xj's.

 

a transfer case drop takes about 5 minutes to do!

 

a t-case drop is just a band aid. if u need one, u should go with a sye

 

A stock jeep technically "needs" an SYE, because the output was poorly considered when it was decided on. however a TCL should fix it.

 

a SYE is tooo expensive, if a transfer case lowering kit will fix it just do that. SYE are ridiculously expensive........

 

yeah after some research i'm def going to drop the transfer case. if i want to do it myself, is that all i need are some washers or do i need longer bolts too? i also don't think i need to drop it a whole inch. i haven't gotten the chance to climb under yet and check it all out so i dont know how many bolts there are to loosen and put the washers on.

 

should be two bolts on each side. you will need longer bolts im pretty sure. You can do washers and longer bolts if you want. I just bought the skyjacker TLC. Washers dont seem as safe to me but dont let me stop you. mine was 1 inch. i kept going through u-joints till i put the TLC on.

 

I have a 3 inch lift with one inch TLC

 

i'm just going to order the drop kit then. thanks a lot for your help.