At ride height, climb under and grab ahold of driveshaft and see if there is any play up or down, left to right

 

I just tried out a 33" zj shaft still the same vibration. So I think it's safe to rule out shaft length and balance.

 

33" exactly if I measured correctly.

 

What happened when you drove FWD. And you said the vibes weren't there before the SYE. What brand SYE was it again

 

I didn't end up getting to try fwd I had to go pull someone home I'm going to pull it now and drive to school tomorrow in fwd. There was a different vibration. This one is more aggressive and louder. I have an advance adapters sye.

 

Did you do the SYE yourself

 

Yes with the help of another guy.

 

If it's still vibrating with different shafts, it's either the SYE was installed wrong, your pinion angle is just enough to screw with you or you have horrible luck gettin a balanced driveshaft haha

 

We followed the instructions perfectly watched the advance adapters video as we did each step.

 

How could the sye be installed wrong?

 

Something could be loose. Who knows. Diagnosis thought process is work from the latest modification backwards. You're newest is the SYE. So work from there first. Go through it and make sure everything is torqued to requirements. Then look at your pinion angle and perfect that. With an SYE, pinion angle shouldn't matter so long as you are close.

Has anyone brought up tires yet? Have you recently rotated them or changed them? Are they balanced? Even tread wear?

 

I checked the torque on everything 3 times, I've changed the pinion angle and it looks right, it's a degree or 2 low. Maybe I just have more axle wrap than I thought. Just had them rotated, balanced and the tread wear was even. All the lock rings were in the right places, I followed the instructions perfectly. Whenever I do work on my jeep I double and triple check everything and research it for weeks prior. Even for small modifications.

 

Did you have vibrations like this prior to the SYE installation

 

Not that I can remember. Still vibrates with only fwd so I guess driveshaft angles are out.

 

That's the best thing. With the vibratons now, do you feel it in the steering wheel. Any sounds.

When I had a bad JY shaft, if I had it in the rear, I would feel the vibrations under acceleration and at the rear. When I put it in the front, I could feel the front end and under my feet vibrating. Can you feel where it's coming from with just FWD.