taken straight from ROF
http://www.rubiconownersforum.com/forums/24-rubicon-faqs/23328-death-wobble-repair-checklist.html
Death wobble and steering wobbles in general are one of the most common problems after lifting your Jeep. I've been dealing with large and small steering wobbles off and on since I first lifted my TJ. It's an ongoing process as things wear. I have ORO's U-Turn steering system, RE 4.5 superflex, and 33x12.5 Goodyear MT/R's and I don't run a steering stab as it can mask problems. This is also my daily driver with a 25 mile (one way) commute that's mostly expressway driving, plus all the wheeling I can do on the weekends. The wobbles in my case are small things that I catch right away and fix before they affect vehicle control. Since I don't know what configuration you have on there, here's some general things to check:
***Remember, once you lift your Jeep, the factory specs will not necessarily work for your situation. Get underneath, get your hands dirty, and learn about your Jeep, in the case of steering, you and your family's life may depend on it!***
***Accept this fact...Death wobble will not be cured by a steering stabilizer. This may mask the symptoms for a while, they will return, potentially more dangerous than before as the worn components are now even weaker!***
1- Trackbar axle bolt TIGHT, hole still round, correct size bolt, bushings/joints in good shape.
2- Tires balanced? Super Swampers are notorious for being way out of balance. I use Centramatic dynamic wheel balancers to keep mine balanced.
3- Upper adjustable control arms to set correct castor. A good self check can be performed by placing an angle finder on the flat plate next to the shock just behind the axle tube. (Check each side.) If it's about 3 degrees below 0, you should be OK, less than that and you will likely have some trouble. Alternately you can use a socket on top of the upper ball joint with the angle finder and get your castor angle that way. In my case, one full turn of the upper arm equals one degree, YMMV. Don't forget to check the angle on the front driveshaft. DS and castor are a compromise to ensure safe vehicle handling with good U joint life, you may not be able to get either exactly correct, shoot for what works best for both.
4- TRE's in good shape, you may even have to disconnect the joints and move them by hand to verify smooth operation. Remember, easiest way to remove TRE's is to hit the surrounding metal piece with a BFH to loosen, don't hit the threaded end or use a pickle fork unless you want to destroy the joint. Grease the joints every oil change, grease is cheap, joints are not.
5- Solid lower control arms to prevent unwanted movement and flex, if you still have the factory ones they could be the problem.
6- Control arm joints tight, my RE superflex joints can be disassembled, cleaned, lubed, rebuilt, and reassembled as required. Alternately I can just tighten them up with an inexpensive tool. RE told me to rebuild after tightening 3 or 4 times.
7- Factory washers on the lower control arm to axle joint. My RE arms came with new washers, so I used 'em. They were slightly smaller in diameter and thickness them the factory, and didn't have the tapered edge to ensure correct axle alignment. Once I replaced them with the factory ones, it tightened things up nicely.
8- Check the joints in the steering wheel shaft itself, two under the hood and one under the dash. I had one wear and loosen up, and it took forever to find it. Felt like problems elsewhere in the steering system because it allows play between steering wheel and the rest of the steering system. I ended up replacing my intermediate steering shaft and was good to go.
9- Wheel bearings (hubs) in good shape? Cheapest I found for my wifes TJ was about $150 at Autozone, made by Timkin, highly respected bearing company. Everybody else wanted around $200. Don't do what the previous owner (idiot!) did to hers, he only tightened the axle nut to hand tight instead of 175 ft/lbs.
10- How about your ball joints? Same goes there, a good way to check is to jack the tire off the ground and see if there's any top/bottom play.
11- Ensure upper and lower shock bushings are in good shape, I had one get cut by a sharp edge on the upper mount, allowed some unwanted axle movement before any dampening occured.
Basically do an inspection of every part from the steering wheel to the tire. Verify each fastener fits correctly in the holes provided with no slop. Each time you find a component worn, or loose, and you tighten or correct the problem, your alignment may be off again. Get a factory service manual or Chilton's to ensure correct torque specs. Near the end of ORO's U-turn install instructions, they give a good step by step procedure for doing a self alignment that you can follow. Basically you use two 4' long 1"x1" aluminum angle pieces (Got mine at Lowes for about $5 each IIRC) held to the wheel with bungies, and two tape measures to check the difference. I do this about once a quarter anyway just to check. Make it part of your routine maintenance as it only takes about 20 minutes.