Or, How to Fix Vibration and Keep Your Shorts Clean

Please note, this is an old writeup I did but it seems like some here could use it…

If you have been roaming Jeep message boards for any length of time you have seen the phrase ‘death wobble’ tossed about once or twice.  It is usually accompanied by some story of near death experience and the face of Jesus hovering over the road until the victim gets his rig stopped and pulled off the road.  I originally wrote these posts off as cry babies.  I figured they where just a bunch of lace panty wearing sissies who couldn’t hack a little tire vibration.

Or at least I did, and then I experienced it for myself.

It really is that bad.  Imagine a shimmy so violent it tears the wheel from your hands and shakes the truck hard enough to lock up the seat belt… all at 50 MPH.

That is death wobble, and obviously something you are going to want to fix.  Fast.

After your first death wobble experience you limp home slightly above idle with sweaty palms intent on fixing the problem sometime, say… yesterday.  Like most people, myself included, you may have turned to the internet for a quick and simple path to solving your problem.

If only it where that easy… 

Upon searching for death wobble and it is related causes and cures you are bombarded with trillions of articles, posts and rants about death wobble.  Of course this is the internet so they ALL disagree with one another.  If you decide to actually ask about it on a forum you will get 75 pages of conflicting responses that eventually degraded into an ill tempered dispute of other users’ family lineage.  Some of the info you get is good and some of it is complete garbage… but how to tell?  And why is there so much conflict about death wobble?

The conflict over death wobble comes because there never seems to be one standard cause of or solution to the problem.  This is partially because no one can seem to agree on exactly what is and what is not death wobble.  Death wobble has become this kind of catch all phrase to describe any front end shimmy, vibe or steering issue on a newer (usually coil sprung) Jeep.  Many cases of ‘death wobble’ are simply a vibration, shimmy or bump steer put down with the wrong name.  Our first step here is going to be making sure you have death wobble and not some other issue so that we can stop wasting your time with this write up.

In order to identify a case of death wobble we first need to define what death wobble is, or isn’t.

To start lets get technical about what death wobble is and why it happens.  When reduced to the simplest terms death wobble is caused by a side to side movement of the front axle that feeds back into the steering system.  Its severity is because under the right conditions the rebound action of the force transmitted to the steering meets the axle as it rebounds on its next cycle of movement causing a violent transmittal of force to the steering.  Each time this cycle happens the effect is amplified until it reaches a disastrous peak.  The problem is most common in vehicles with coil springs and link type suspension (Jeeps and Dodge trucks are notorious for it).  However, it is not LIMITED to them.  Any type of solid front axle suspension can get death wobble, even leaf sprung ones.  It is not as common and generally not as violent in other types of vehicles but it is possible.  That’s right kids, death wobble is not a Jeep only issue, any 4x4 with a solid front axle can have it.

OK, now we know what it is the next step is how does the problem manifest itself, or put more simply what are the symptoms of death wobble?  Death wobble, as defined by this article, is a violent low frequency high amplitude vibration, at any speed, in the steering that causes a violent shaking of the entire vehicle and feeds back through the steering with enough force to make the wheel hard to hold and continues beyond one or two cycles.  It may or may not have an obvious cause and seems to happen at any speed and does not go away until almost stopped.

Right, OK so what does that mean in English?  Well the low frequency part means that it is not a fast ‘buzzing’ vibration.  The high amplitude part means that the vibration is large or covers a lot of ground.  In other words what you will see vibration wise is that there is a very large and forceful movement of the steering wheel in your hands.  It moves quickly but not super fast.  The shake will feel like the whole front of the vehicle is going to fall off, not from a fast vibration but from the sheer beating that happens.  One of the most important parts of our symptoms is that it ‘continues beyond one or two cycles.  There are many suspension issues that can cause a violent shake or thump in the front end and a violent movement of the steering, the most common is bump steer.  However, death wobble is a CONTINUED shaking and violent movement of the wheel.  If what you have happens and then goes away immediately you do not have death wobble.  Sometimes it can be induced by a large bump or hard steering input, other times it just seems to show up on it’s own as you drive up through a certain speed.  There is no standard speed above or below which death wobble can occur but generally it will always happen around the same speed range on a given vehicle at a given time, like when my Blazer had death wobble it would show up and start between 35-45 MPH and would persist until the vehicle was nearly stopped.

Now that we know if your problem is death wobble or not we can get down to what causes it and maybe set you on the right path to fixing your problem so you can stop buying new underpants every time you drive your 4x4.

As we discussed earlier death wobble comes from a side to side motion of your front axle syncing up with the side to side play in your steering in an extreme and discomforting manner.  In the perfect world you could just find that play, tighten it up and solve the issue, but this is not a perfect world.  The front end and steering in your 4x4 is not hard anchored and even when new, nor should it be.  You also have to consider that even with a loose front end you need something to induce the death wobble so you are really looking for two problems, first the looseness that is causing the play and eventual death wobble and also the defect that is inducing the vibration to start the death wobble. 

To make it even more complicated depending on the vehicle and components you can have a very loose front end with a small vibe to start it the exact opposite.  What I like to do is first start by looking for extremely loose or worn front end and steering components.  During this step many people immediately turn to the steering stabilizer and in many cases its replacement ‘solves’ the problem.  98% of the time this is not a fix, it is a band-aid.  Partially because the death wobble is probably the reason your stabilizer is bad in the first place.  In fact, it probably spent the last part of it’s life masking the problem so it could get as bad as it is.  If you just change the steering stabilizer and look for no other cause I can almost guarantee that your problem will return, even worse then before.  Plus by putting a band-aid on the problem you have given the real cause of the death wobble time to get worse possibly causing further and more extensive damage to your front end.  Long story short, even if the stabilizer change solves the problem don’t stop looking!

Usually I start with a quick inspection for severally worn parts in the steering and front end.  In a coil spring vehicle pay close attention to the track bar and on leaf sprung rigs look closely at the spring and shackle bushings.  Make sure and look at everything.  Control arm bushings, ball joints, king pins, EVERYTHING and pay attention to any looseness, it doesn’t take much to start death wobble.  If your death wobble is occurring immediately after a suspension lift or change to the suspension also check your alignment, especially the castor.  A drastically incorrect caster angle will cause even the most minor looseness or steering issue to become amplified into full on death wobble.

Now that you have an idea what in the suspension is loose and letting it move around you need to find what is inducing the vibration into that looseness to initiate the death wobble.  For this you may really need to get creative.  Often times the source can be some play in the steering linkage but in all reality it can be ANYTHING.  Or even a combination of things, so don’t stop looking after finding one obvious issue.  Also keep in mind that just because you find a loose steering component that may not be the source of your problem but a symptom.  Remember that stuff has been beating around under there pretty hard, it is very possible that a bad tie rod end is caused FROM the wobble and not the cause OF it.  Be sure not to overlook items like stiff u-joints, the steering gear and tires.

Now fix the stuff you found loose and you should have solved your wobble issue.  If not, look harder.  I know this is not the quick and easy exact answer many of you are looking for but sadly there is no one size fits all solution to death wobble, that is why there is so much conflicting info out there on what it is an how to solve it.  However, with a clear understanding of the problem and its causes you should be able to identify and fix the cause without to much trouble.

tjtank99 said:Ah man, this is such a good post. I almost shat myself remembering the experience I had not too long ago…

No joke!

That's why I always ask people if they are sure it is Death Wobble; thanks to the internet DW has become the catch all phrase for a front end issue on a Jeep and a lot of people do not appreciate just how bad it can be.  My first experiance was in a stock '87 XJ I bought for parts.  I hit some railroad tracks and the thing just went nuts.  I almost ended up crossing into oncoming traffic before I got it stoped and off the road, I thyink I did no fater then 25 MPH the rest of the way home!