transfered my lift to my new(used XJ) got vibes now...

Bought a 94 4.0l XJ Np242 Auto, transferred my 4.5" lift kit from my 94 2.5l XJ Np 231, Ax 5 and I've got vibes!!!

Do I need an SYE kit? Who makes one? $ is limited as usual but still wanna wheel my new toy!!

Help!!

First, measure the angles of the u-joints at both ends of the rear drive shaft. The AW-4/242 combination is longer than the AX-5/231, which means a shorter drive shaft. The same amount of lift will thus cause more of an increase in the drive line angles. A SYE is always a good idea, but you might be able to eliminate the vibrations by shimming the rear axle to adjust the pinion angle, or perhaps a transfer case drop (although I really, really dislike those as a matter of principle ... but many people have found that they solve the problem).

Thanks Eagle, I am guilty of being one of those who did a transfer case drop. Before the drop it was unbelievably bad!

Did the drop still had a slight vibe at 20 - 35 mph but will go away before and after that range. Will try the shimming this weekend, hope it will work.

Thanks again!

You should have an easier time in figuring out the problem, as Eagle has mentioned you have a longer shaft with the MT. Shimming or adding an extended shackle will help out the pinion angles.

Also, you may have to get an extended slip yoke, this allows less bind on the u-joint itself by adding the extra length on the yoke and not the shaft of the slip yoke.

Chuck has a good point -- the u-joint at the transfer case may be at the limit of its range. The so-called "extended" yoke everyone talks about is slightly longer, but its real advantage is that the throats are more open than the stock XJ yoke and this allows the joint to operate at a greater angle without binding. The large anglularity will still eat u-joints faster than a small angle, but at least if the yoke isn't binding they wear out, they don't snap.