usaf_mike

UPDATE: Look at the pics below



Ok first before I start I have a:

2000 XJ 4 door 2WD Auto

I lifted the jeep yesterday and put in a 3" rough country with full leaf pack. After installing it and several days of driving it I have the following problems. At consistently 20 mph I get slight vibs up until 30 where it stops. That happens everytime, however every once in a while going a little faster than that if I let off the gas I hear a binding/grinding noise coming from underneath me and it happens again once I reapply the gas peddle. It doesnt happen all the time though.

I have eliminated the motor because I took the belt off and turned the jeep on to hear for noises. I have read numerous threads on t case drops and SYE but my car is a 2WD so I dont think thats it.

What do you guys think. ANY IDEAS?

Any help would be appreciated.

jeepxj19

Check ur ujoints.

Ladies

Sounds like you need a t-case drop.. But I don't know much about the 2wd lifts?? Still has to be a rear drive shaft that needs the angles corrected!

usaf_mike

U joints are fine checked them already.

I thought I dont have a T case I have a 2WD

lynskynbnd

Slip Yolk eliminator and Double Cardan driveshaft($$$$!), or raised motormounts may help(le$$)

usaf_mike

someone said to grease up the slip yoke and it would take care of the binding noise but I didnt have that noise before the lift. Would the lift cause this noise to start and would greasing the slip yoke help that.

Also anyone with a 2WD fix the vibs?

Here are some pics

usaf_mike

I think this might be an issue as well. My driveshaft looks like it came out a little I dont know. How do I push it back in if it is or is it like that because of the lift? Im guessing dropping my crossmember would bring me back into spec since I have a 2WD.

Jeepxj1234

Yes your drive shaft will come out because there is now a greater distance between the rear axle and the would be tcase (I guess that's the transmission?). I guess the motor body mounts would be your best choice since you don't have a tcase

lynskynbnd

In the Third pic down that shows the front Ujoint you can see that the slip yolk and shaft do not line up.
They need to be in a strait line.
This is where the vibration is comming from. When you accellerate the tourque and spring wrap will increase this vibration.

A Double Cardan joint at the front will stop this. Otherwise you'll need to get the Yolk and Shaft lined up by raising the engine or lowering the trans.

lynskynbnd

Example of a stock shaft vs double cardan on Tom Woods shaft
and a stock cross member vs Rusty's Off Road drop crossmember.
(the drop cross member doesn't lower ground clearance and is stronger than stock)

93gc40

Check U-Joints firsts. Lube the Slip yoke, but that looks to be internally lubed by the trans fluid. Kinda hard to do a SYE or TC drop on a 2wd, as you don't have a TC to attach them to. You do want the rear pinion to be pointed AT the Trans output shaft. You will need to shim the axle to get this angle correct. Are tires balanced? Have you done the alignment yet?

lynskynbnd

The trans mount and crossmember in a 2WD and 4WD mount the same way, to the transmission not the Tcase.

A drive shaft can be made with a Double Cardan and a Slip Yolk. Just sak Tom Woods or any reputable drive line shop.



And yes, the axle yolk and drive shaft need to be in a strait line also, But that needs to be done after any engine or trans level changes.

Also in the pics the Ujoints apear to be as old as the shaft. While they may not feel loose, they could be binding. Have you pulled the shaft and felt the movement in them?
If you go the cheapest route and drop the cross member to line up the shaft it would be a good idea to replace the joints anyway.

usaf_mike

UPDATE:


I got my Daystar 1.25 T-Case/ Crossmember drop kit in today and installed it. What a difference it made in my jeep. I have no vibrations like I used to have and no crazy clunky noises when I let off the gas while driving.

I have a 2WD. If your experiencing any of these symptoms I would get this kit and install it first.

Thanks to all for the help.

Bossokee

I'm fairly sure that on a slip yoke driveshaft, the transfer case and differential yokes are supposed to be parallel. Can anyone else vouche for me here? I know that mine are and i have almost unnoticeable vibes on 3.5" rear lift on my '98 with a stock crossmember and driveshaft.

Jeepxj1234

Yes the slip yoke and the rear axle pinion should be at the same angles therefore parallel. There was a good drawing on one of these threads recently..