Zackqb2

I installed a hack n tap and its a little worse then before 0-50 it's fine the after 50+ it's vibes

FIREMANRAY

Pull your front shaft and drive it. Mine has vibes only when the front shaft is in. I replaced it with a new "woody" shaft and still have the same problem. Not sure what the cure is going to be.

EvilMaster

How much lift?

Did you shim it properly to get the proper pinion angles?

N20jeep

^^^this

Zackqb2

It's the rear shaft vibrating, would it do this if my output shaft isn't cut the the proper length.

Metmknice

Are you sure your tires are balanced? Have you thought about balancing your d-shaft? Is it an oem front shaft or aftermarket?

Zackqb2

OEM shaft and I'm in the need of some new tires but its coming from the shaft

N20jeep

take a picture of your pinion angle

Zackqb2

Mike H.

Yes.
The whole idea of doing and SYE is to shorten the length of the output shaft. The longer the shaft extending from the t-case, the more leverage it has to bind things up inside the case.
The length of the shaft and it's leverage have much to do with the vib's.

Consider this, the earlier Jeeps (pre '96 I believe) have a shorter output shaft than the post '96's... and, low and behold the pre '96's can typically be lifted to 4" without vib's, where as the longer shafted post '96's are know to vib at as littel as 1" (plenty of factory upcountries came off the lot with vibrations).

Cut the shaft to the lenght identified in your instructions.

cw50must

Make sure every part of the shaft is greased. I had a shop install a brand new shaft with no grease.

mark's91-XJ

are your leaf spring u-bolts really tight, check

Zackqb2

No more vibes I checked my U Joints and one was shot. I went and pick up a precision U joint and works great. Yes everything on my jeep is tight.

FIREMANRAY

Which u-joint was bad?

Zackqb2

this first U joint in the double Carden it was shut all the little needle bearings where crushed and spun all to the bottom