Strange noise/vibration

vehicle 1994 xj NP 242 dana 35 rear axle 3" lift OME springs and 1" lift shackles

I have installed this item from quadratec

http://www.quadratec.com/products/52237_05X0_PG.htm

Basically when I accelerate everything sounds fine. However when I let off the gas pedal there is a somewhat loud vibration noise coming from whats sounds like the rear of the vehicle. If I feather the gas pedal, to keep the vehicle coasting but not letting the engine rpms slow the vehicle there is no vibration.

This drive shaft coming out of the transfer case doesn't seem to be too far out. .5" inches or less. According to quadratec I should not have had to change the pinion angle to install the replacement yoke, but I am thinking I may have inadvertently.

Suggestions please?
Thanks
dgwelsh

Assuming everything else is good (u-joints, pinion angle, balance) then I would venture to guess that you may have overtightened the new u-joint straps causing the vibration. Aside from that usually vibration or either acceleration or coasting only is a pinion angle issue.

I'm running just the 3" lift from OME on my 00XJ 4.0 aw4 231 8.25 and it does the same thing. I haven't gotten around to checking the pinion angle yet but thats what I'm leaning toward.

I had the same exact noise. Thought it was the no slip. I dropped the tcase and have no more noise what so ever.. x2 on pinion angle.

thanks fellas,

headed to Seatle for a couple days, looks like a little project is gonna be waiting for me.

To follow up, How should I go about properly diagnosing this problem and fixing it?
thanks
again