00Cherok33

I have a 2000 With about a three inch suspension lift and 31's. If I am coasting down a hill or holding my foot slightly on the gas I get a vibration. If at highway speeds I hear it when I apply and let off of the pedal. I have lowered the t-case and replaced U joints.. anyone have any ideas on what this might be?

00xjalex

I'm having the same problem! Someone told me to shim the rear axle

93gc40

Start by making sure your tires are balance and bearings are good U joints, all 7 are good. Now, if you still have the vibes. Measure your drive line angles, with the TC drop removed. Now reinstall the TC drop in combination with axel shim to make the rear pinion input angle 1-2* below the output angle of the TC. Next save some money and do a SYE and re-shim the axle.

00Cherok33

What do you mean by SYE? I will look into shiming the rear axle. Also which bearings should I check? I removed the front driveshaft to eliminate that. The rear wheel bearings are new

93gc40

I mean ALL the bearings, even the new ones, front and rear wheel and front and rear pinion.
DO NOT Check the drive shaft ujoint by grabbing and shaking. Take the shaft out and actually inspect the u-joint , 5 minute Job with a 5/16 socket.
Last time I changed my Ujoints they where felt fine when installed. But when I pulled the shaft I found that they were nearly frozen and 1 had a broken cap.

00Cherok33

I replaced the U-joints but will check them again. My jeep came with a D-35 which I swapped for an 8.25.. would that make a difference?

93gc40

Might also check the bearings in the axle, trans mount, could be bent axle. I would check both front and rear ends. Since they are connected together by the Transfercase even when 4wd is desengaged, vibes coming from one end can "feel" and "sound" like it is coming from the other.