Well guys after about 5 months of searching for answers for Death Wobble I think (time will tell if it comes back) I have found some answers. This information is MAINLY for LIFTED Jeeps, but I will add some more information for all the stock guys with death wobble too.
I found some Jeep enthusiasts here locally that had done a lot of coil spring conversions on Wranglers and on Cherokees. They said they have had Death Wobble on the Cherokees almost every time they did a coil spring conversion. The reason they discovered for the Death Wobble is that the drag link on Wranglers comes from the pitman arm down to the left front hub and then from the left front hub straight over to the right front hub. This is a strong link geometrically. Unfortunately on the Grand Cherokee's and Cherokee's they used a different link system... the drag link drops from the pitman arm straight down to the front left hub, but instead of the second arm attaching at the left hub and going to the right hub they attached the second arm in the middle of the first arm so you have this triangular type figure created. The problem with this setup is when you start lifting the Jeep with a Budget Boost the front axle is pushed down and since the trailing arms arent replaced the axle is actually pushed backwards. This change to the axle position changes the geometry of the actual steering setup and starts allowing for more and more play. This is why it seems that GC's with budget boosts are more susceptible to DW. This is also the reason why guys with taller lifts will many times never see DW on their Jeeps. If you get taller lifts that come with drop pitman arms then many times you wont have DW because you have returned the geometry on the drag link back to an angle that will not allow for very much play in the steering.
Other reasons that DW can be formed are:
The Steering Stabilizer is shot and causes the steering not to be tight enough
The Track Bar is bent which allows for a little bit of movement in the axle
The tires are warped or the alignment is messed up
There are some bushings on the front end somewhere that is allowing for some play.
**The things listed above can happen with or without lifting the vehicle. **
Now for some Solutions:
Everyone should start with the steering stabilizer I would say. It is only around $60 bucks for a good one from Rancho or Old Man Emu. If that does not cure the problem then I would IMMEDIATELY go to an Offroad Equipment shop. Walk into the shop and point at your vehicle and say Death Wobble. If they start laughing and know exactly what you mean then you are at the right place if they look confused and don't have a clue then you are in the wrong place. Once you find a shop that knows what Death Wobble is then you need to talk to them and they will tell you a lot of what I have told you here. Then ask them where they have taken their trucks to get aligned after they are lifted. Most alignment shops don't have a clue except for "factory specs"... if you can find a shop that knows how suspension really works then they know all the tricks for maxing out every centimeter to get your vehicle fully aligned. Normally the alignment shops that do the alignments for offroad shops will know exactly what DW is and be able to check everything for you. Many times... find the problem.
Now as far as specifics go... if you have a 2" budget boost then you need to make sure they roll the caster back to around -6.00 to -9.00. Since your axle has been pushed down and slightly backwards then you need to get it pushed forwards at least as far as the factory position or even further forward. This should be possible with a 2" budget boost, but if you have something taller then you might need even more caster. Anyways... a good alignment shop should be able to tell this... a lot of "normal" alignment shops just try and move it back to the factory spec when you are going to need more than that to compensate for the lift.
Basically... if you have DW, it can be fixed. It is normally a combination of several of the things I mentioned. My particular problem was the Track Bar, Tires, and Alignment problems because of my budget boost. I did buy Kevin's Track Bar Conversion which was great and did add some stability, but was not my total solution in the end. I also bought a OME steering stabilizer which helped make the steering tighter but did not solve the problem either.
The key is to find a shop that knows suspension and knows what DW is. From there... you WILL find a solution.
P.S. I know it is long, but hopefully it helps. There might be more info from other people's experience to add here, but this is what I have discovered in my journey towards Death Wobble Recovery.
Last edited by jdpaysnoe; 08-01-2005 at 05:13 PM..
ask WVD to have this posted in the faq section. Great info.
00 4.7 Laredo...KYB gas shocks, ADDCO rear sway bar and Firestone Destination tires.
08 Z71 Suburban
94 5.9 Laredo 6.5 RE lift with 35 Maxxis Bighorns
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Thanks for putting that into words.
My old XJ had it and it was not fun at 70mph on the turnpike.
Why is it I never see any drop pittman arms for the ZJ, that sounds like it would do allot towards a cure.
Has anyone tried other pittman arms to see if they fit?
I use a Jeep
You drive a car
94 I6 ZJ at 4", 33's and front locker and 4.11 gears. Swampy Bypass.
[B]Black Jeep Club Member Ver. 2 #51[/B]
Last edited by jeepholic; 12-22-2004 at 06:35 AM..
I appreciate the thanks from everyone. I am just putting up what I have figured out from much more experienced people than myself. I will see if I cant post with in the FAQ section. Just as a note to everyone... I would say a really GOOD offroad/alignment shop will be your best friend with curing the Death Wobble.
Blaine59: If you get the BB make sure you get extended length shocks. My factory shocks were completely extended and were not preloaded so I think that helped form some of the DW problems I had. The second thing I would do after you get the BB is find a good alignment shop... tell them you have the 2" lift and that you are concerned that your alignment might be off and your caster might be off also. Tell them to try and move the caster somewhere between the -6 and -9 range. -6 is still within the "stock" specs so they should be willing to do it. If they check it and your caster is already in those ranges then you should be pretty good to go. If you take it to a shop who doesnt know anything about lifts then they will most likely take a look at your alignment and return it to whatever their "factory" specs say and not compensate for the lift.
The Steering Stabilizer is a VERY good thing to get, but it is not needed. I say it is VERY good because the Old Man Emu (OME) one I got from Kevin (Kevinsoffroad.com) is about twice as thick as the factory with a rock guard around it. My steering felt a LOT more solid afterwards. I would basically replace this only if you think your factory one is a bit on the weak side or if you think it is shot. Its kind of a pain in the *** to do because you either have to buy/rent a pitman arm puller or use a BFH to get some one of the bolts that is pressure fitted. Definitely doable on your own, but not all that much fun so wait until you need one or just wanna spend some extra money. It is worth getting eventually though.
By the way, to anyone who lives in the Oklahoma City area. The offroad shop I went to here in OKC that knew all about DW was 4 Wheel Parts on N. May just north of 23rd Street. The alignment shop that fixed me up and knew a LOT about DW also was Jackie Cooper Tire and Electronics on NW Expressway and 63rd Street.
To everyone else not in OKC... 4 Wheel Parts is a very big chain of offroad stores and are in general very knowledgable. If you have one in your area you should try them first. Just point and say Death Wobble. You will know immediately by their reaction if they understand or not.
I have found that each time that I have had DW, I have been able to cure it by adjusting the caster alone. I lifted the ZJ in stages. 2" B/B, 3" coils, 3.5" coils plus B/B. Each time I got DW. Each time I adjusted the caster (even after an alignment) and the problem was solved. I did this on a friend's TJ experiencing DW while enroute to Tellico. Problem solved.
Worn parts will contribute to it, but caster is an often overlooked adjustment.