Lift kit rear vibration issue...

So I got my new 3.5" lift on today, looks like 4" in the back... and my worst fear is now a reality... VIBRATION!

maybe vibration isnt the right word to describe this... this is what happens. At street speed (25-45mph) i have minimal to no vibrations coming from the rear. its only once in a while that i will hear some grinding type noise coming from the rear but only when i take my foot OFF that gas. ?

on the highway i can get up to 70mph with minimal to no noticible vibrations, and i will hear the same clunk/grinding noise only when i take my foot OFF the gas... I have asked around and searched and have found nothing on this. Could it just be a bad U joint? bad pinion angle? the driveshaft going into the rear pumpkin is probably definitely not straight on. I have no idea what degree it would be, but its not extreme, but its still not a straight pinion angle. Shims? drop transfer case?????

Any ideas? once again, minimal to no vibrations when driving, only vibrations/grinding noise/clunking noise when taking foot off gas (decelerating) HELP!

do you have a SYE? that is probobly what is wrong. send us pictures of your rear driveline angles, and is yours a pre97 or post?

SYE... I hate even the thoght of having to put one on. ill take some pictures tomorrow of the drive line angles. The only reason its really odd is that the grinding/clunking is only when taking my foot OFF the gas...

actually, thats def a u-joint. it does it when ur foot comes off the gas because in an auto tahts when it goes into neutral so the shaft's u-joint bangs on the opposite side. like in my manual when the u-joint was going out every time at a stop light when i would have it in gear and let out the clutch a little it would bang into place... replace that u-joint, thoes vibrations are causing the u-joint failure though. replace the joint to fix the banging but it will eventually return from said vibrations, get a t-case drop see if htat helps

SurfXJSnow said:

SYE... I hate even the thoght of having to put one on. ill take some pictures tomorrow of the drive line angles. The only reason its really odd is that the grinding/clunking is only when taking my foot OFF the gas...

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I agree with emr1101 being a u joint and don't be to scared of an SYE it's really not the bad at all so don't rule it out completely there really straight foward and doable in an afternoon. -Eric

Justpunchit said:

I agree with emr1101 being a u joint and don't be to scared of an SYE it's really not the bad at all so don't rule it out completely there really straight foward and doable in an afternoon. -Eric

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well thats a relief to hear its probably just the U joints. ill do those first, then shim it, if that doesnt work then drop the T case, if that doesnt work then i will look into an SYE... eventhough i still have no idea how one works.

A tcase drop is cheap easy fix. I dont know if a shim can rival 1" drop. Good luck, check all angles, and bolts and nuts. Post a pic of the beast as well.

i say go for it you got your work cut out for you

what would YOU do first? T case drop or shim it?

do a t-case drop then shim accoringly, your axle should have been shimmed to begin with when the lift was installed. If your pinion seals does not leak now it WILL soon enough if your axle's yoke isnt parallel to your driveshaft. t-case drop in and hten shim accordingly it all needs to be done similtaneously a shim alone will NOT fix the wobble unfortuantly