I have a roar with a slight vibe, sounds like it's coming from the rear of the vehicle.

It only happens when letting off of the accelerator at speeds faster than 30

It has a 6.5" lift and I do not have a Slip yoke eliminator, think this may be the problem? However, the t-case has a drop kit and the rear end has wedges.

Also the lift is new and the rear hasn't settled, it sits about 2-3" higher in back.

Any ideas?

 

Yup that's it. I've only got about 4" in the back and I get the same sound/vibe. Even with your t-case drop and wedges you're probably still at more of an angle than I have.

Go out and flex the crap out of your rear end and try to loosen it up. Either that or drive around with some extra weight in the back for a while til they settle.

Sounds like a nice setup though! Any pics??

 

Thanks for the advice, I'll find some to help put some weight in the back, see if it clears or get quieter.

I'm working on pics here soon. If the weather lets up.

But to give you a visual. Dark Blue 96 XJ county, 6.5" rusty's lift, 35x12.50 Maxxis Trepadors, 15x10 black rock aluminum rims, Bushwacker cut out flares and tinted windows.

 

Common to get vibes on decelleration with a lift.

You need an SYE, no doubt about it. I wouldnt be surprised if you spit the rear driveshaft off or break a ujoint because the working angle is so severe.

Manual or auto trans? You may be able to fix this cheaply with an XJ or ZJ front shaft used in the rear with a cheap SYE kit.

 

It's an automatic. Would the front driveshaft from an XJ have to be made longer to fit?

What about the hack and taps I keep hearing about, are they just as good as a SYE?

 

A hack and tap is the cheaper style SYE.

What transfer case do you have? Do you have a FULLTIME position?

 

What degree are your wedges at? I have a Rubicon 5.5 long arm kit - had the wrong wedges (4 degree) in and it had the same problem. I put a slip yoke in and 6 degree wedges... now it drives like it used to. Hope that helps.

 

Update:

I got a friend to help me out with adding weight in the back of the XJ. We managed to drop the rear end 3", it sat just slightly higher in the rear, maybe a 1/2 inch. We ended up putting about 600 pounds of shingles in the back, and I've been driving it around that way since. It actually rides alot better over bumps in the road. Since we did this the rear has settled about 1 inch. I'll slowly take out the shingles to keep the ride height the same untill they're all out.

I guess this is one way of doing it huh?

Oh, BTW, the roaring sound had completely gone since the weight was added. You guys were right, the driveshaft angle was too steep. Right now it has no vibes or strange noises. Once it stettles I believe i'll be ok without a SYE kit.

I'll take pics of the shaft angles and ride height sometime after the holidays.

 

Carried this damn load of shingles around for a week now. It was left flexed every night rotating sides. I thought I was getting somewhere at first but after removing all the weight it's back to where it was, almost 3" higher in the rear. Not to mention it rides like a

Someone suggested removing 1 or 2 of the leafs since they came with 6. Is this a good idea? Maybe I should contact Rusty's with this matter. It's just a PITA. These kits should come pre-settled from the factory.

 

Anyone?

 

i wouldn't go that far as removing leafs i would just go sye cause the more you drive it the better the ride gets it toke 2 months and driving my jeep every day before i lost the extra height from my 4 1/2 inch lift and i still measure 5 over stock not counting tire height