Ok just built my xj. Was factory. It has a RC 6.5 lift, 33s, transfer case drop, quick disconnect seat bar links. Took it to have aligned yesterday and at highway speed 45-55 the vibration turns into a death wobble. Not all the time but random on it. I can slow our of it or power out of it. Trying to figure out what's going on. Any ideas and help would be greatly appreciated

 

jack it up and start grabbing stuff to find out where the play is.

 

I know there is play in the front axle with the front drive shaft. Feels like there is play in the front gears.

 

Check all of your steering and replace your u joints if they have play..

I'm guessing you have a 98..they can be picky when it comes to needing a sye or if a transfer case drop will work.

 

Ya I've got a 98. And I put the transfer case drop in it. And before it, it had a vibration and after it cured it. But not now with it at highway. I've got the SYE but no drive shaft for it yet.

 

So the death wobble is before or after you got it aligned? Did the alignment make any difference?

 

It's after. Before the toe was off and the tires were squealing and didn't do it. After I got it, that's when it started

 

I got massive dw after I lifted mine. I put in a rc 4.5 inch lift. Stock I had no problems, after the lift and new tires it was to the point I could barely drive it. I started going over that checklist that is on the diagnosing your death wobble thread. I did everything on the list, checked and rechecked everything. After completely replacing all the steering rod ends, gear, drop pitman arm, new hubs, adj upper arms, ball joints, multiple alignments and re balancing the tires twice it was still there. I was ready to light the jeep on fire and walk away. Then I talked to a buddy of mine that has a service shop and he told me to "road force balance" the tires. Well low and behold the wobble is gone. One tire balanced fine on the spin balancer but was way of with the road force balancer. My advice is jack it up, push pull and tweak on everything. Inspect everything up close. Replace the worn parts that are obviously bad.If nothings bad go spend 30 bucks on the road force balance for the front two tires And see what happens.

 

What's a road force balance? I've never heard of that

 

It balances the tire while applying force to the tread to simulate the tire rolling on the pavement under load versus a spin balancer just spinning the tire in the air and figuring out where the weights need to be. After road force balancing my wheel weights moved probably 30 degrees from where they spin balanced out. And they zeroed each time they balanced on the spin balancer. I had it done at a goodyear shop because they were the only ones that had one around town. Most places dont road force balance, usually only the large tire chains or places that deal with hi perf tires do.