"Death" wobble?

[az350x]

So, junior's 90 lifted XJ has a rather disconcerting habit while driving. I've not experienced it myself, but his description is as follows. The drive typically starts out with no issues. After driving for a bit at highway speed, the vehicle starts to shake somewhat violently, necessitating a fairly quick slow-down to under 20 mph before it clears. As the drive goes on, it happens again at slower speeds, and requires slow-downs to a near-stop each time to alleviate it.

Anyone ever hear of something such as this? Obviously, being ol' Dad and all, I feel we need to get this figured out ASAP. I'm thinking of starting with tire balancing all around, then heading to the alignment shop for a front-end evaluation. Wheel bearings also crossed my mind as a culprit- might jack the front end tomorrow and check for wheel wobble...

Is there a frequent culprit with these rigs that might cause something like this? I've owned and worked on LOTS of vehicles, ATV's, airplanes etc., but have NEVER owned or worked on a Jeep before, so I'm really looking for some feedback from you experts if possible.

Thanks!

[ironmanandy]

Death wobble has a singular origin. It is a resonation that occurs in the steering from the tires being out of balance. Everything that follows is a result of this and either adds or inhibits the resonation. You can replace every part on the front of that jeep but until you break the bead on those tires and have them re balanced to zero they will wobble.

The next contributing factor after that is fixed would be the loose parts and bolt holes that are ovalized from the wobble. The track bar must be tight and aligned with the drag link in length and in parallel plane. The castor must be correct if the jeep is lifted and the control arms are not the right length the steering knuckles are steering across an arc instead of a plane and they want to point left or right not straight.

I can write a book on this but the best steps to follow are:

balance tires. If they are cheap tires you will need to balance them often. Mud in rims or thrown weight will make them out of balance. Low pressure can spin a tire on the bead under torque resulting in misplaced tire weights.

Steering damper. There is only 1 damper on the market worth buying. OLD MAN Emu. I sell them on my site www.ironman4x4fab.com but they are cheaper on quadratech.

This damper actually will fight the wobbles the harder they hit. Every other damper on the market is just a 50/50 valved shock turned sideways. They work less with every cycle as the oil begins to cavitate and foam. The OME has a nitrogen foam cell that actually stop the cavitation.

If the vehicle is lifted the proper length control arms and track bar are the next issue to deal with

There is a lot of wrong information out there on this subject. I have this conversation daily with customers and have been very successful in helping folks fix the DW blues.

Feel free to call me tomorrow if you need more assistance.
704 796 3502
Andy Carter
www.ironman4x4fab.com

[bluedragon436]

^^ What Andy said!! I'm fighting this right now with my 98 as well... it is a very common occurrence... especially on lifted vehicles w/ solid front axles!!

[ironmanandy]

The more wobbles you have the worse its going to tear up your front end and make it harder to fix.

The violent oscillation will ovalize any mount hole.....
eeeep!

[az350x]

AWESOME feedback- thanks! I'll start with a rebalance tomorrow then and go from there. The tires are Good Year 33's, that look by the date code to be a couple years old with less than 50% tread left.

Andy- I followed your link and then checked quadratech, and you're a buck cheaper on the Old Man Emu, so even if they were a bit cheaper there, based on your helpful feedback YOU will be receiving our business when we get to that point.

Thanks again, and I'll keep you updated!




Death wobble has a singular origin. It is a resonation that occurs in the steering from the tires being out of balance. Everything that follows is a result of this and either adds or inhibits the resonation. You can replace every part on the front of that jeep but until you break the bead on those tires and have them re balanced to zero they will wobble.

The next contributing factor after that is fixed would be the loose parts and bolt holes that are ovalized from the wobble. The track bar must be tight and aligned with the drag link in length and in parallel plane. The castor must be correct if the jeep is lifted and the control arms are not the right length the steering knuckles are steering across an arc instead of a plane and they want to point left or right not straight.

I can write a book on this but the best steps to follow are:

balance tires. If they are cheap tires you will need to balance them often. Mud in rims or thrown weight will make them out of balance. Low pressure can spin a tire on the bead under torque resulting in misplaced tire weights.

Steering damper. There is only 1 damper on the market worth buying. OLD MAN Emu. I sell them on my site www.ironman4x4fab.com but they are cheaper on quadratech.

This damper actually will fight the wobbles the harder they hit. Every other damper on the market is just a 50/50 valved shock turned sideways. They work less with every cycle as the oil begins to cavitate and foam. The OME has a nitrogen foam cell that actually stop the cavitation.

If the vehicle is lifted the proper length control arms and track bar are the next issue to deal with

There is a lot of wrong information out there on this subject. I have this conversation daily with customers and have been very successful in helping folks fix the DW blues.

Feel free to call me tomorrow if you need more assistance.
704 796 3502
Andy Carter
www.ironman4x4fab.com

[ironmanandy]

Glad to hear it! Feel free to call any time. The phone number is my personal number for my mobile. customers call me 24 hours a day

[XJ Wheeler]

Good idea to check your alignment while your at it. Free and easy to do.

[cantab27]

I thought a steering stabler liser kinda hides the problem some what......have got the Dw after putting in 6inch lift.........am sorting it next week , will report in on what I find and fix...

[ironmanandy]

A good stabliser is an integral part of any non hydraulic ram type steering box based straight axle setup.

The steeper the angle of the steering arms the less effective they are in traveling flat across a plane. This adds to the wobbles.

Most folks assume that since they had their tires balanced at some point that they are still in balance.

This is rarely true. With tires that are oversize and used off road they should be rotated and balanced ever other oil change.

A

[az350x]

Well, I just drove it less than a mile to Discount Tire for a balancing, and it happened to me TWICE! The first time was at 35 mph, I hit one little bump in the road and BAM! It felt like the front axle was trying to separate itself from the truck. I had to slow to under 20 before it'd stop. The second time I was going through an intersection at about 20 mph and it happened again. Holy crap. This thing is absolutely unroadworthy until it gets sorted out. I've NEVER experienced anything like this before. My son says he thinks the lift is 6.5", and MAY be Rough Country. If I post pics of the underside, can anyone possibly identify it? There's no visible markings left on the components at this point.

Thanks again for the feedback!

[4.3LXJ]

A higher lift like 6.5" will exacerbate any problems with the front end. Take some pics and show us what you have. Also, have your son start the Jeep and saw the steering wheel back and forth while you look at the front end components. You will be looking for anything that moves that shouldn't. When taking pics, we need to know what there is for control arms too.

[cantab27]

Ah cool thanks Andy ......might fit one then .....

[az350x]

So here are some pics of the beast. Wondering if anyone can identify the brand and height of lift? Shocks are Rancho. Steering stabilizer is very covered with oil, lol, so not sure of brand, but planning on ordering an OME from ironmanandy soon. I'm not looking forward to solving this mystery- it felt HORRIBLY sloppy when it happened, and I'm scared to find out how extensive the damage may be.

To be honest, the steering is horribly sloppy. It literally feels like the whole front axle slides around under the truck when cornering. The whole truck leans and rolls around during cornering. The front tires squeal during tight turns on asphalt (and actually even during not-so-tight turns). There are numerous pops and groans from underneath when maneuvering slowly. I've got a bad feeling about this...

http://i227.photobucket.com/albums/dd74/az350x/VW%20stuff/Ryan-%20Jeep%20stuff/IMG_4661.jpg

http://i227.photobucket.com/albums/dd74/az350x/VW%20stuff/Ryan-%20Jeep%20stuff/IMG_4654_zpsbcbcc582.jpg

http://i227.photobucket.com/albums/dd74/az350x/VW%20stuff/Ryan-%20Jeep%20stuff/IMG_4655_zpsa5fad6e5.jpg

http://i227.photobucket.com/albums/dd74/az350x/VW%20stuff/Ryan-%20Jeep%20stuff/IMG_4658_zpse2dda0e6.jpg

http://i227.photobucket.com/albums/dd74/az350x/VW%20stuff/Ryan-%20Jeep%20stuff/IMG_4656.jpg

http://i227.photobucket.com/albums/dd74/az350x/VW%20stuff/Ryan-%20Jeep%20stuff/IMG_4657.jpg

http://i227.photobucket.com/albums/dd74/az350x/VW%20stuff/Ryan-%20Jeep%20stuff/IMG_4659.jpg

[4.3LXJ]

The first thing I see is the spacers front and rear. That front spacer would have caused the castor angle, set by the fixed control arms to be rotated forward, which would contribute and even cause the death wobble. The castor angle should be about 5° to the rear. That diff looks tilted too far forward in the pic. Second to figure out the lift, use the info in this link.

http://www.xjtalk.com/showthread.php?t=8144

[nickxj94]

That draglink and tre bar looks like hell looks bent and tres look worn out, lift looks like it could be a Rubicon express, that trackbar looks like crap too I would check and see if it has any play side to side turning the wheels back and forth, check the hub assemblies, balljoints for any movement any more than a 1/8 inch there bad and will contribute to dw and also the pinon angle looks out like he said ^^ those uppers adjustable? If so adjust the pinon down some and I would look into a over the knuckle tre swap to fix that ugly draglink setup that's stock and probably over its limit.also I looking again them springs look like there bending towards driver side and front of jeep may need to adjust that trackbar axle may not center and pinon is out pushing the axle forward when it needs to come back a little needs adjustable uppers I seen it don't have them or take them spring spacers out it may fix all of it!

[prerunner1982]

Welcome to the Jeep world!

[az350x]

That draglink and tre bar looks like hell looks bent and tres look worn out, lift looks like it could be a Rubicon express, that trackbar looks like crap too I would check and see if it has any play side to side turning the wheels back and forth, check the hub assemblies, balljoints for any movement any more than a 1/8 inch there bad and will contribute to dw and also the pinon angle looks out like he said ^^ those uppers adjustable? If so adjust the pinon down some and I would look into a over the knuckle tre swap to fix that ugly draglink setup that's stock and probably over its limit.also I looking again them springs look like there bending towards driver side and front of jeep may need to adjust that trackbar axle may not center and pinon is out pushing the axle forward when it needs to come back a little needs adjustable uppers I seen it don't have them or take them spring spacers out it may fix all of it!

Could I get some definitions on the acronyms used in this post?

"tre bar"
"trackbar"
"tres"

I'm not familiar with these coil spring suspension setups, so the names of the parts are somewhat foreign to me.

Thanks! :)

[4.3LXJ]

Track bar tie rod end (spherical rod end in your case)
Track bar - goes from the frame to the axle. Also known as a pan hard bar
Tres - tie rod ends

[4x4Dalton]

Could I get some definitions on the acronyms used in this post?

"tre bar" should be track bar
"trackbar"
"tres" should be these

I'm not familiar with these coil spring suspension setups, so the names of the parts are somewhat foreign to me.

Thanks! :)




Sent from my bulletproof iPhone using the Flapmyjaws app :)

[XJ Wheeler]

That's a Rubicon Express kit, 4.5" with 2" spacers and blocks most likely. And 6.5" on short arms is quite a steep angle on the control arms. Plus, at 6.5" that steering really needs to be upgraded, 4.3LXJ is has extensive knowledge on the subject. Does the transfer case have a slip yoke eliminator? If you don't know just post a pic if the rear of the transfer case and we can tell ya. If it were mine i'd rip the spacers and blocks out, the rest of the components should all be built to compliment each other. The upper arms aren't adjustable, meaning if you want to keep the spacers in the front you will need adjustable arms (a couple hundreds dollars unless you get some used ones). Hope this helps.

[Dredwolf]

This is why I LOVE this forum....everyone is trying to help solve this problem.

There is far more expertise already in this thread than I can offer, but it looks like this XJ had sway bar disconnects at some point. Once the other issues are sorted out, adding a front sway bar back may "stabilize" the pavement experience.;)

[az350x]

So, am I correct in assuming that likely the best place to start would be by removing the 2" spacers? Sounds like they're a cosmetic-only jury-rig to me, that just exacerbates any problems that DO come up, such as this wobble for starters.

How hard is it to remove them? I'm assuming they're the plastic-looking cups at the top of the coil springs? I've done leaf-spring lift work before; I've also done McPherson strut replacements before, as well as VW torsion stuff (not fun), etc. I suspect I have the tools and the overall aptitude, but if anyone has any links to anything helpful regarding this specific process, I'd appreciate it.

Thanks again- I'm very grateful for all the helpful feedback!

[4.3LXJ]

As far as the spacers go, the cheapest thing is to remove them. But you have options. If I remember correctly this is the boy's rig. Might break his heart to go down. You could also get some lowering brackets that will lower the place the suspension control arms attach or go to a long arm set up. All up to you. Brackets I thin are around $200 and long arms are $500+

But check the other stuff out first before spending any money. Make sure everything is tight

[az350x]

I guess you're right about breaking his heart, lol. There I go thinking like a Dad instead of a young un', lol. I'll start digging around underneath looking for anything loose and/or elongated. I think I wanna go to the carwash first and try and defunk as much of it as I can- there's a fair amount of oil under there from the oil leak I mentioned in another post. I'll talk to my son and see what direction he wants to go. He's short on $$$ and going to be needing this thing in service as a DD before too long. He informed me he's been watching this thread- I think he should join the forum and claim ownership of his beast! :wink:


As far as the spacers go, the cheapest thing is to remove them. But you have options. If I remember correctly this is the boy's rig. Might break his heart to go down. You could also get some lowering brackets that will lower the place the suspension control arms attach or go to a long arm set up. All up to you. Brackets I thin are around $200 and long arms are $500+

But check the other stuff out first before spending any money. Make sure everything is tight

[4.3LXJ]

Yes, he should join and learn for himself. It will be better that way

[Rybob]

Junior checking in.

Ordered the OME stabilizer from ironmanandy tonight.

And as far as downsizing the lift goes. I'm not heartbroken about it, I'm just concerned will my 33s rub on trails at 4.5" lift? I can upgrade height the rig way later, I just need to know how pressing of a matter it will be now

[bigjim350]

I would look for a loose trackbar, and balance the tires. Then see if it has death wobble. If it doesnt well then you dont need to take out the spacer, if it does....well cross that bridge when it gets there. Tons of people are running 4.5" lifts with spacers and dont have death wobble.

[4.3LXJ]

Junior checking in.

Ordered the OME stabilizer from ironmanandy tonight.

And as far as downsizing the lift goes. I'm not heartbroken about it, I'm just concerned will my 33s rub on trails at 4.5" lift? I can upgrade height the rig way later, I just need to know how pressing of a matter it will be now

You can do just fine with 33s on a 4.5" lift. Your fenders are cut out so it would not be a problem. It is possible to run 33s with no lift with trimmed fenders. But one of the things some people do is try to lift cheaply with spacers. Sometimes it works with no problems, sometimes not. So what you and your Dad should do is check everything out to see that it is tight. If it is and you cannot find anything else wrong, then you will have to correct that castor angle on the front axle. As I said before, you have options. The only one that doesn't involve money is removing the spacers

[Rybob]

You can do just fine with 33s on a 4.5" lift. Your fenders are cut out so it would not be a problem. It is possible to run 33s with no lift with trimmed fenders. But one of the things some people do is try to lift cheaply with spacers. Sometimes it works with no problems, sometimes not. So what you and your Dad should do is check everything out to see that it is tight. If it is and you cannot find anything else wrong, then you will have to correct that castor angle on the front axle. As I said before, you have options. The only one that doesn't involve money is removing the spacers

Ok thank you for the info! I will keep this updated as i work on it, should be fairly soon!

[az350x]

http://i227.photobucket.com/albums/dd74/az350x/VW%20stuff/Ryan-%20Jeep%20stuff/IMG_4654_zpsbcbcc582.jpg

Okay- could I have some "bar identification 101" training here?

In the above pic, please tell me the names of the following bars-

1- the horizontal one in front of the axle
2- the angled one that attaches to the Pitman arm (with steering stab attached to it)
3- the crazy bent one attached just inside the driver's coil spring (looks made that way, but all those bends? Should it look like THAT?)
4- the two short ones attached to the top of the axle that run aft and attach to the frame

Thanks!

[4.3LXJ]

1 - tie rod
2 - drag lik
3 - track bar - yes
4 - upper suspension links

[az350x]

1 - tie rod
2 - drag lik
3 - track bar - yes
4 - upper suspension links

Perfect- thanks!

That being said, after having my wife turn the wheels from side to side while I watched underneath, I noticed a few things.
1- the whole axle seems to actually move laterally some. The upper suspension link bushings on top of the axle do look a bit sloppy.
2- the drag link bushing at the Pitman arm looks like it MAY have some play/slop in it
3- the tie rod end boots are shot- tie rod ends are pretty greasy, so it's hard to tell if they're worn or not.

How many of these do you think would play into the wobble scenario? Tires are now balanced.

So- now for a general question. While I've never been a "die hard" off-roader, I have owned quite a number of 4x4's, most of which have been straight-axle rigs. NONE have been Jeeps or coil-spring however, so this type of suspension setup is completely new to me. I've noticed that this XJ of Ryan's feels similar to a lifted Wrangler he owned briefly earlier this year, in that the suspension feels unbelievably soft, and I even get the sensation that the axles are shifting around underneath me when driving. Is that normal for this type of lifted suspension? I'm guessing that the "softness" is a benefit for articulation, but should it really feel like the undercarriage is literally sliding around underneath me? Just curious...

Thanks again!

[az350x]

I've only found one thing loose so far- the track bar was VERY loose at the frame end. When I grabbed the bar and shook it, it chattered, and I noticed that there was probably 1/8" of slop where that bolt goes through the bracket. I've tightened that up. Still looking for more....

[nickxj94]

I've only found one thing loose so far- the track bar was VERY loose at the frame end. When I grabbed the bar and shook it, it chattered, and I noticed that there was probably 1/8" of slop where that bolt goes through the bracket. I've tightened that up. Still looking for more....

That's probably the main cause then :thumbup:

[4.3LXJ]

You have probably found the main cause of your death wobble. The first pic I saw of that track bar I suspected that might be it, but I reserved judgement until you made your observations. So to answer one question, no the axle is not supposed to move back and forth under the Jeep. When it does the steering changes. When that happens if it is rapid, such as when you hit a bump or a tire bounces, the steering changes which throws the body to one side. When it does, it rebounds the opposite way and the process is repeated. If a resonance is created, you have death wobble. Also, the front of the XJ is nearly identical to the Wrangler. So you have a track bar problem with an aftermarket track bar. The upper joint on it is a spherical rod end. These work well when new, but over time since they are not protected from the elements and dirt, they will wear out and get loose. So my advice is to replace it with something more serviceable. You cannot go back to stock because of the lift with or without the spacers. So the best thing to do is to contact Andy again and get one of his track bars. They are a double shear design, which means that there are replaceable bushings on both ends and you can get his with a stronger frame bracket. Also check the steering box for play, it probably needs adjusting too.

[az350x]

I just drove it around the block, and over the same stretch of road that I was on (same lane even) when I first experienced the wobble the other day. I was going a bit faster tonight, and when I hit that same pothole, there was no wobble. BUT, the front end seemed to dive a bit, and then the truck sort of swayed/rocked back and forth. Is this the track bar issue you mentioned? When I wiggle the track bar now, there is a tiny bit of play in that heim-type joint at the upper end of it. Very strange sensation when going over bumps.

I'm going to head to the alignment shop on Monday. The way the tires chirp on smooth asphalt, and the way the front end looks when parked, I suspect that it had a shade-tree alignment if anything at all. I believe they'll evaluate it for free, and could tell me what other areas they see that need attention.

[4.3LXJ]

Get your alignment then we will go from there

[oderdene]

http://i227.photobucket.com/albums/dd74/az350x/VW%20stuff/Ryan-%20Jeep%20stuff/IMG_4654_zpsbcbcc582.jpg

Okay- could I have some "bar identification 101" training here?

In the above pic, please tell me the names of the following bars-

1- the horizontal one in front of the axle
2- the angled one that attaches to the Pitman arm (with steering stab attached to it)
3- the crazy bent one attached just inside the driver's coil spring (looks made that way, but all those bends? Should it look like THAT?)
4- the two short ones attached to the top of the axle that run aft and attach to the frame

Thanks!

We have great picture here

http://www.xjtalk.com/showthread.php?t=2111

[nickxj94]

That trackbar heim is likely worn out from previous owner not keeping it tight or lubricated so I would definitely replace the end or get a new adjustable track bar, that thing needs the toe set too I can tell by the pic its out to much. With that little play it will cause it to road walk a bit and toe out too will also cause a slight dw or shake in steering wheel, I been fighting my 2000 xj for a couple days again I fixed it today

[XJ Wheeler]

Tony, from the pictures you have posted i don't see a front swaybar. Some think of them as "unnecessary" (probably the reason for its absence), however in my opinion, with a lifted coil spring suspension they are quite needed. This is most likely the reason for the swaying/rocking sensation you have felt, and possibly the axles moving under the vehicle one as well. My suggestion, hit up a junkyard for a front sway bar and invest in some disconnects. There is actually a thread on the topic of opinions of the different "discos" offered, if you or your boy would like to research some. http://www.xjtalk.com/showthread.php?t=12653

[XJ Wheeler]

Here is a great picture some one made up, its of a wrangler but the noted pieces are similar enough.
http://i1108.photobucket.com/albums/h401/xj-wheeler/tjsteering_1_.jpg