Very Discusted

[clydethepirate]

Well, I got my 2.5" lift installed today and Now I have the dreaded vibration that alot of people have.

The shop that installed it has a great reputation for Jeep suspensions.
Well, I called him up and he said I probably needed to drop the transfer case about 1/4" and the problem would stop, he offered to do it but I said I could do that.

I done it with a 1/4" flat bar and drilled the holes so it fits good between the plate and the frame.

The vibration is better, but still very much there....
Anyone got any advice before I just give up and get rid of it.

Jeeps are simple yet complex at the same time..... A Paradox :???:

 

[pinaplebob]

Get rid of the whole jeep? That's a little extreme.

How are your U-joints? You changed your geometry, I would check the easy stuff first.

 

[JPNinPA]

What kind of lift?
The vib is definitely in the driveline?
Transmission mount intact and tight?

 

[clydethepirate]

It's a rough country lift. That may be my problem
Yes everything is tight

 

[JPNinPA]

Jeep YJ Suspension Lift
This one?
Take it back and have him check the drive shaft/ pumpkin output angle. They had to mount the axel to the springs and if the angle at the pumpkin is off you'll have issues. If adjusted properly you might not need any spacers.

 

[clydethepirate]

Im not sure which RC kit it is, I just ordered through our local 4x4 shop. Do you know what the correct angle is?

 

[69jeepcj]

A 2 1/2" lift typically doesn't require a tcase drop, or shims. He probably suggested the 1/4" drop instead of the usual 1" for that reason. You can call him back and ask about degree shims for the rear end. They go between your spring perch and the spring to correct pinion angles. your tcase drop and some shims in the back could cure your problem. a slip yoke eleminator could help as well but is more pricey than shims. As for the pinion angles, they should be the same, parrallel. someone posted a good pic of how they should be the other day. I'll try to find it and post.

 

[O_M_Jeep]

 

[69jeepcj]

Your angles should be set up like this:

If this were a cj, I would say ditch the tcase drop, but I have read all kinds of stories about wranglers having vibrations issues after small lifts. I also read that some wranglers left the factory with vibration issues. typically one of these.., shims, tcase drop, slip yoke eleminator, double ujointed driveshafts are used to correct your problem.

 

[ljrubitm]

If you look at the Rough Country site all the YJ kits have rear shims built into the springs. I hate you say,but are you sure they did not mount the rear springs backwards. Take the front DS off and see if the vibs are still there.

To bypass a SYE I've heard and read that you can use a XJ front DS on the rear of YJ and XJ. That way you have a cv drive shaft.This will also help with drive line angle. You will need to take it to a drive shaft shop to make it the size you need.

 

[JEEEPRS]

Does the vibration come and go or is it steady at a certain speed?

 

[clydethepirate]

the vibration is at about 35

 

[69jeepcj]

Another thing to check is your pinion bearing. put it in nuetral and grab your rear pinion yoke and see if there is any play in it at all, if so your pinion bearing may be worn and that will cause a slight vibe. the outer bearing is pretty easy to change and is usually the one that go's.

 

[clydethepirate]

Well got it straightened out. This is an extremely high kit for a 2.5" so I had to use a 1" drop on the Transfer case which I will probably be able to take off in a couple thousand miles...
Anyway that seemed to take care of the vibration.
Thanks for everyones help...... Im still learning

 

[superj]

Glad it's fixed man

 

[RockOn93]

Nice!