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.
The Reason:
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.
Jeremy
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.
The Reason:
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.
Jeremy
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.
