Well finally after resolving the brake issues finally test drove my jk with solid 60s front and rear.

Running 35 MTZ on brand new wheels all balanced
Tom Woods 1350 Driveshafts
Solid 60 diffs front and rear
Front & Rear Axles are alinged
Suspension and wheel balancing done

now when driving on highway i am getting vibrations when i go over 80MPH.

Where do I start here to fix the vibration. Yes I did the search and getting some idea but again want to hear from the experts on this issue.

I can also unlock the front wheels to test the rear driveshaft.

 

I not able to offer any constructive advise, so here's a bump, maybe WOL will chime in with some help. Good luck

 

What kind of vibration is it? Is it a real fast type vibration like a hum noise? Or more like a shimmy? One of the lifts I installed had a hum type vibration at speeds above 70 mph and we determined that the front pinion angle was too great. We took out some of the caster, which decreased the pinion angle and solved the vibration problem.

 

Just a thought. Even though you had the tires "balanced" they may not be perfect. They probably got them as close as they could.

 

ok thanks guys for the questions so far...

i dont have any vibrations around 40 mph but as soon as i hit 80 to 90 mph i get a hummmming kind of vibration feeling it in the seat and the entire cab has a hummmm a little ting vibration in the steering

i totally agree the wheels are to be balanced few times before they are close to perfect

we tried to adjust the rear only lower control arm one notch on each side to see if the vibrations increase or decrease and i think it has improved a little bit.


one question after replacing the stock drive shafts to double cardin style driveshafts is it expected to feel certian vibrations on high speed compared to stock shafts or will the tunning of the pinion will completly fix the vibrations???

 

Tuning the pinion should fix it.

I was told by the local Jeep shop that most just live with it..bs...

After going up to the 6" lift, my driveline vibe disappeared. Since the added lift changed the caster/ pinion angle, I am certain that is what resolved it.