Death Wobble: How To Fix Your Own Case Of The Dreaded Death Wobble

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What is Death Wobble? 

If you have to ask, then you’re lucky, because most likely you’ve never experienced it.  If you ever do, you will know this terrifying experience immediately, and you will never forget it!  If you have already experienced it, then you know “Death Wobble” is the horrible front end vibration that feels like your vehicle is about to fly apart.  This makes if difficult to maintain control of your vehicle and usually starts when one tire (usually the right tire first) hits a groove or bump in the pavement somewhere around 40~50mph.  Death Wobble is quite possibly the worst possible downside to having a coil-sprung front suspension on a vehicle with a track bar or Panhard bar.  Jeep vehicles affected by this design are the Cherokee XJ and Comanche MJ, the Grand Cherokee ZJ and WJ, as well as the TJ / LJ and JK Wranglers.  Other vehicles affected by this phenomenon include trucks like Toyota, Ford, and Dodge Ram (a page written specifically for Dodge Wobble is located here).  Death Wobble is so extremely difficult to diagnose and fix because it is actually caused by slop in the entire steering system as a whole, not by one component.  We’ve been experimenting with and learning about the root causes of Death Wobble since 2002, and have experience that VERY few other shops possess.  In fact, we get calls for help from other 4×4 shops, and auto mechanics from all over, requesting help and our proven replacement parts to solve their customers’ Death Wobble problems.  To diagnose and fix Death Wobble correctly, your mechanic needs to look for “play” everywhere in the steering and front suspension system, searching for anything that could have “play” in it.  It’s very time consuming to find a Death Wobble fix and can be downright dangerous while you are in “testing phase”, trying to exorcise this demon from your Jeep or Truck.  This page discusses Death Wobble Causes and Cures specific to the Jeep vehicles.

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For a more in-depth discussion and tutorial, I’ve written my first book on Death Wobble, entitled “Death Wobble: Causes and Cures“, which is available here.
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Where do I even start?

Death Wobble Alignment

Death Wobble – Front End Suspension Components – 4x4Xplor.com

The place I tell people to start is with an overall visual inspection.  Spend 10 solid minutes under the front end of your vehicle, visually inspecting each one of the steering components.  You will be looking for shiny spots on steel, rubber, or polyurethane, which is typically indicative of suspension components that are moving around when they are not supposed to be.  Pay CAREFUL attention to the track bar (also called a Panhard Bar inside and outside the USA, as well as variant spellings (misspellings?) of  trackbar, tracbar, and trak-bar ).  The Track Bar is  often the culprit in many cases.  If ANY of your bolts are even the least bit loose, Death Wobble also can manifest itself and make your life a living hell, so check for looseness EVERYWHERE!

Here are some other steering components to check over for looseness or improper movement:

  • Tie Rod Ends (all four, plus the upper track bar end)
  • Upper and lower Ball Joints
  • Track Bar mounting bracket bolts
  • Steering Box Brace
  • Track Bar Ends

 

Alignment

If everything appears to be “normal” on the underside of your vehicle, and you’ve verified the bolt tightness on both ends of the track bar, the next thing to do is get a front end alignment, making sure that caster (frequently misspelled as ” castor “) is set correctly as well as toe-in.  If you have been offroading and have bent your tie rod even slightly, that, also, will throw off your alignment.  Plus, it’s only $40 or so at your local alignment shop. 

By the way, DO NOT let the alignment shop talk you into a four-wheel alignment!  This is only useful on vehicles with independent rear suspension in my experience, and since there are no adjustment points in the rear of a live-axle vehicle ANYWAY, you’re merely paying for a service that you won’t get.  Furthermore, if you have a lifted vehicle, make sure that the alignment shop you choose knows the variant specifications for lifted vehicles.  DO NOT let them set it to the “default/stock” settings!  A good quality alignment shop familiar with lifted 4×4 vehicles will know these settings; a poor quality shop will likely tell you that it doesn’t matter whether it’s lifted or not and that they use the stock specs.  If they tell you this, walk away immediately, or hang up the phone and call the next shop.

 

On track?

If you are now *certain* that the front end alignment is set correctly, and that you have not replaced ANY other front end components recently (including tires or wheels) which may have caused the oscillation to begin, I tell people the next most suspect thing is the factory front track bar.  Over time, the tie rod end on the upper portion of the Panhard or Track Bar develops “play” in it due to wear and miles on the vehicle (some applications like the Grand Cherokee WJ, Ford truck, and the Dodge Ram have a rubber bushing configuration instead, which also wears out).  The same findings often go for the lower end bushing, which has a rubber or polyurethane isolator bushing in it, and this “slop” will allow the Death Wobble oscillation to occur.  Aftermarket trackbars generally come with urethane bushings that allow a LOT less “play” (with respect to movement / crush) than the factory rubber bushings do.  The problem with most aftermarket track bars for the Jeep is that they also come with either a Heim joint, Johnny Joint, or tie rod end on the upper end of the Track Bar.  This works fine for a while, but wears out over time, leaving you right back where you started; with a large mess in your shorts, a temporarily deafened right ear (from the wife screaming for dear life, or, quite possibly at YOU, for buying the Jeep to begin with, lol), and an overall high level of frustration with your entire rig in general.  I developed our Track Bar Conversion kit for XJ Cherokees and ZJ Grand Cherokees to eliminate that problematic (and expensive to replace) previously mentioned joint, as well as for the additional flex benefits you get from it.  If you are running a Cherokee XJ or Grand Cherokee ZJ with or without Death Wobble, and it has more than 1.5″ of lift, I highly recommend you check it out.  Many aftermarket track bars, as well as the stock track bar, are completely ineffective in managing Death Wobble due to their “effective angle of operation”, particularly if you are above say 2 or 3 inches of lift.  Keep in mind that another alignment is necessary after replacing ANY front end components, especially if Death Wobble still remains.  Sometimes you might get lucky and not need one…but be forewarned.

 

Bushings

A product we have found to work VERY well in getting rid of Death Wobble is our exclusive Hard-KOR brand SuperDurometer Track Bar Bushings.  These bushings are also available for the Track Bar Conversion, and fit most “normal” sized 1.6″ ID by 1.25″ deep aftermarket and factory track bar end loops, which would originally take a 1.6″ OD rubber cartridge bushing.  Our SuperDurometer Track Bar Bushings are about TWO TIMES as hard as the typical polyurethane bushings that come with most aftermarket track bars (which typically are made by Daystar or Energy Suspension for most of the various aftermarket manufacturers).  Polyurethane bushings are also one of the least expensive replacement parts in the steering components, so it makes sense to try them.

 

Looking for stability

The next thing to check is your steering stabilizer.  I recommend AT THE MINIMUM, replacing your stabilizer (or dampener, as it’s sometimes called) at the same time as whatever worn components that you find during your inspection.  This “combination punch” is often more effective than changes caused by each individual part alone.  Death Wobble shakes EVERYTHING and loosens up other components at the same time.  Replacing the stabilizer by itself often times doesn’t eliminate the problem directly, but it often helps with some other poor handling characteristics that cause the onset of Death Wobble (such as wandering, for instance).  A new stabilizer will tighten up the entire steering system, and It’s also one of the least expensive parts to replace in your steering system while attempting to remedy the problem.  I ONLY recommend two stabilizers to ANYONE who is having trouble with Death Wobble; our Hard-KOR Steering Stabilizer or the Old Man Emu (OME) SD40 stabilizer. These two seem to be tighter and work better for stopping vibration than the other steering stabilizers on the market.  I know, I’ve tested them all, trying like hell to fix this issue on a WJ years ago.  They are also the most heavy duty that I’m aware of.

 

Brace for impact!

Another product that we’ve developed to assist in preventing Death Wobble is our Steering Box Brace.  We have a brace for the Jeep Cherokee XJ and the Jeep Grand Cherokee ZJ; both the I6 and V8 models.  Our brace holds the steering box tightly, allowing the additional stresses of running larger than stock tires to be directed to BOTH frame rails, rather than depending on the three little bolts that hold the gear to the frame. These bolts often work their way loose over time, and if they do, will snap the gear box ears off the box and leave you stranded somewhere you don’t want to be.

 

Oh, the pressure

Another source of Death Wobble is over-inflated tires.  You should have somewhere around 30psi or so with stock tires, and the larger your tire are, the less pressure they should have.  See Boyle’s Law and consider how much more air volume is inside your 33″ tires compared to stock tires.  As an example, I run around 38psi in my 37′ tires.

 

Getting your bearings

The last thing that I can mention that has caused Death Wobble in the past, is hub bearings.  If there is a little slop in them over the years and miles, they MAY indeed help to cause oscillation as well.  I mention them last because they are the most expensive to replace and probably least likely to be the root of the problem (thought they might be a component adding to the problem).  

 

What’s your angle?

If you’re running a lift kit of 4″ or more, then while you have the front end apart, you should consider adding some offset upper ball joints to your Jeep in order to return the caster back to what a stock Jeep would be.  Be aware that on 4×4 models (especially FULL-TIME 4×4 models), by NOT changing the ball joints to the offset type, you add more vibration to the front drive shaft since you are also turning your pinion angle downward in conjunction with every caster angle increase.  In other words, you can’t have one without the other, and on the full-time 4×4 models, you’ll get a little vibration at highway speeds by NOT doing so. Compared to getting Deat Wobble, however, this is a very small price to pay.

Hopefully, this short checklist gets you started on the right path to helping you fix your Death Wobble problems once and for all.

Very Sincerely,
Kevin

 Additional Resources:

Fox News: What you need to know about the “Jeep Death Wobble”
Wikipedia: Speed Wobble Definition
Wrangler Forum: Diagnosing Death Wobble