crux

Been attempting to track down some vibrations post lift on the cherokee. Vibes kick in around 70 MPH and above. I've been able to narrow it down the the back half of the truck so it sounds simple enough. Had the tires rebalanced last week and they were off on one by 0.25oz. Don't think its the ires any more as it the same vibe continues.

Was thinking possible drive shaft issues since it was swapped out for a Tom Woods version. Angle is 2.5% off which is right in spec. Tried today getting it up to 80MPH and dropping it in Neutral. Vibes continued.

Tried tires, tried measuring the angles on the drive shaft and still not able to get the vibes out. Took some grease to all joints even thinking it might help. I'm now searching for some expert troubleshooting help from the forums seeing is we could get rid of all the bad vibes.

ericfx1984

there are a million different reasons...

while you should really just google it or use the search function... here is what I can tell you

most likely bad u joints or you need a SYE or t case drop

wait is your truck lifted?

Jeepxj1234

Hah yes for starters is it lifted?? ^^

jeep801

I would say the u joints would cause vibration. Did you say it is only when its in neutral?

crux

Truck is lifted.

The vibes kick in above 70mph and really get going at around 75mph. This holds true if in gear or neutral.

Jeep has a SYE and TX case drop installed.

Drive shaft is one from Tom Woods a Double Cardan. The rear yoke is inline with the driveshaft as depicted on his site.

All U-joints are new on the rear.

Tires and rims recently balanced within 200 miles.

Google results primarily focus around the DW shakes from the front end. Everything up front is brand new and solid. This jeep is shaking its rear.

freegdr

tire balance would be a good place to start, also front shaft is a possible cause

VTJeep

x2. any lift over 3" will prob cause too much angle on the DS. u joints are notorious... i jest had to replace the rear joint, and the whole front DS cause its got the ****ty CV... ugh... got it for a good price for around here. 85 bucks vs. the 120 i though i was gonna be paying... thank god for JY's!

well, you have all the right gear for your set up... i know you checked tires, but are the old? and what about mud in rim? i know you said it was from the rear, but what about front wheel joint? idk, thinkin out loud...

crux

All of the steering components up front are new so don't think that could be it. The front DS sounds interesting what were the issues and solution? Tires have a total of 3,700 miles on them so if they are spent already I'll never buy that brand again. No mud in the rims. Checked and rebalanced on 3/24/11.

Seems to be coming from the rear of the Jeep so was thinking of driving with just the front but at 75MPH do not know if that is safe. Might try removing the front DS instead seeing if that helps or not.

phoenix901223

Who drives 75-80 in an xj lol I don't trust stock steering and brakes on large tires going that fast...