Passt

Hey all,

I recently installed the Iron Rock Off Road 6.5 inch critical path long arm kit on my 2000 XJ. To compliment the kit, I installed a Rugged Ridge SYE, and a Tatton rear driveshaft. I have the rear axle shimmed 8 degrees, and the pinion angle is 1 degree less than the driveshaft angle.

The drive is perfectly smooth until 25 mph, where the vibrations begin. By 30 mph, they are quite noticeable. By 40 mph, they lessen a bit, but are still there slightly. I've only had it up to 50 mph since the install. All of the above info is DURING acceleration. If at any point I let off the gas and am coasting, the vibrations disappear.

I have tried removing the front driveshaft to see if there is any change, but it did nothing.

I am just looking for some guidance as to what to try next, or what to look for. I'm assuming someone has gone through something similar before. Thanks in advance for the help!

ExTrEmExJ99

hows the trans and engine mounts?

Passt

The trans mount is brand new, I installed it while doing the kit. I haven't looked at the motor mounts. Good idea.

Passt

Engine mounts look good. The motor moves very little when popping the gas pedal while in drive, with foot on the brake.

andrewmp6

Did you have a front end alignment after the lift was put on?

Passt

Yes, the front end has been aligned.

B-Dick

What kind of ujoints are you running?

ZINGGG

Exhaust coming into contact with the crossmember at all?

93XJLI

i get some minimal vibes from 35-50 or so. after that, theyre completely gone. i dont worry about it. if your rear view mirror isnt shaking youre fine.

Passt

My steering wheel shakes after about 45.

I am not 100% sure what type of u-joints are on there. It is whatever Curtis Tatton uses on his custom driveshafts. They are greasable, I do know that. I want to say he uses spicer, but I'm not certain.

No, there is no contact with the crossmember.