XJ experts I need some help.. trying to resolve some driveline vibes. 3.5” lift pinion angle on my particular jeep I set at 11 degrees, my driveshaft is set at 13 degrees. I have an sye and to my understanding I should have the dif pointed 1-3 degrees below the transfer case. I still am experiencing vibes at 60+. Removed front driveshaft, replaced motor and trans mounts. This only started to occur after the lift install.
Driveline vibrations
- Thread starter Joshm24
- Start date
- Location
- Henderson, NV
What Drive line are you using? (New/Used) Also, what is your front pinion angle look like after the lift? The front driveline is always spinning on an XJ regardless if you're in 4x4 or not. Vibes could be coming from the front too.
Either your front driveline is vibrating due to bad pinion angle,
or
Your rear driveline is out of balance.
You can remove the front driveline and drive around and if your vibes go away - then you know its the front. If not, go get the driveline balanced.
One thing to note though, The XJ doesn't have a way to properly adjust Caster angle on the front axle. Caster angle is increased or decreased by adjusting the upper/lower control arms.(If your lift kit allows) Only issue is, this negatively affects your driveline angle since you are rotating the entire axle. So, you have to find a happy medium between Caster angle, and acceptable driveline vibes.
Either your front driveline is vibrating due to bad pinion angle,
or
Your rear driveline is out of balance.
You can remove the front driveline and drive around and if your vibes go away - then you know its the front. If not, go get the driveline balanced.
One thing to note though, The XJ doesn't have a way to properly adjust Caster angle on the front axle. Caster angle is increased or decreased by adjusting the upper/lower control arms.(If your lift kit allows) Only issue is, this negatively affects your driveline angle since you are rotating the entire axle. So, you have to find a happy medium between Caster angle, and acceptable driveline vibes.
FusiliJerry
NAXJA Forum User
- Location
- Philadelphia
Coasting or accelerating? If coasting, a less likely cause but one that was present with mine was that someone ran the front diff low on oil and the carrier and pinion bearings were shot. New ones eliminated my 65-75MPH vibes when coasting. The tell-tale was metal in the oil even when changed somewhat frequently. Amsoil Severe Gear did help minimize it before I got it fixed though. Still have a vibration at 75-80 when accelerating but that was there before too.
