What Causes It and What To Check For
Actually, don’t do the Harlem Shake—hope-fully that fad has died by the time you read this. Also hope your Jeep does not develop death wobble. Death wobble! Dom, dom-dom-dom! It sounds horrible doesn’t it? Chances are that if you have been playing Jeeps for more than a few years, you have at least heard about that super scary moment when the steering wheel whips back and forth violently and the whole Jeep shakes. It sounds scary, and trust us, it is. If you have experienced death wobble, then you already know what it’s like. Within seconds your brain realizes something bad is happening and asks several questions; “Oh, poopy! I can’t steer…can I slow down? Should I speed up? What do I do?” Generally speaking, the best thing to do is hold that steering wheel tight as hell and back off the gas pedal so you can coast to the side of the road. Jamming on the brakes may help, but it often causes a bad situation to become worse. What causes death wobble? What can you do to avoid, prevent, or cure it? Well that, our friends, is the point of this article. We will try to outline all the causes of death wobble, how to narrow down which of these issues is causing your shakes, and maybe point you in the right direction in order to fix the issue. The real problem with death wobble is that it is usually caused by several factors working together. Solving it will only come from a comprehensive examination of several factors. Here are some tips and parts to mark off your checklist if your Jeep has developed the shakes.
Know that guy with the funny feet that point towards each other? How about the guy whose feet are spread out going in two different directions? Maybe you are that guy or gal? Well, chances are that your Jeeps front tires are like this, too. It’s actually a good idea to have tires that are either pointing ever so slightly together and in some instances ever so slightly apart. We generally recommend having your front tires toed in about 1⁄8- to 1⁄4-inch, but one recommended course of action to cure death wobble in JKs is to toe the tires out 1⁄8-inch.
Tie-rod ends are movable, wearable parts that see lots of different forces and abuse. If and when these parts get worn because of hard use and improper maintenance they can develop slop or play. This slop allows things to move you don’t want to. Loose or worn out tie-rod ends can be the cause of death wobble. To test them, jack up one tire at a time grab the tire at the three o’clock and nine o’clock positions, then try to turn the tire back and forth by alternatively pushing and pulling on the tire. Any movement indicates warn out tie-rod ends. The best course of action is to replace them with high-quality parts.
The steering knuckle on your modern front axle is held on with upper and lower ball joints. These parts are very similar in design and function to tie-rod ends and like the latter part are subject to heavy loads and wear. Add in bigger, heavier tires and wheels with less than factory backspacing and the forces acting on your ball joints increase. If and when your ball joints become worn they can contribute to or cause death wobble. To test your ball joints, again jack up one of your Jeeps front tires, this time grabbing the tire at the six o’clock and twelve o’clock (mmm, lunch time) positions, then try to rock the tire. If you encounter play in these parts, the best course of action is replacement.
Caster and Camber Angles
If the term caster angle leaves you feeling like you want to pull your hair out, we are sorry for you. But the fact is that having too much or too little caster can cause problems for your Jeep’s steering. The rake, or angle, that your front axle leans back helps your front tires track straight down the road and also assists in your steering’s return to center. Adding lift to a Jeep’s suspension can throw off your factory caster angle. If your Jeep has too little caster angle, it can be a candidate for developing death wobble. As always, too much of a good thing ain’t bad. Add too much caster angle and your Jeep will wonder down the road like it’s lost as the two tires fight to follow their own independent path. To check caster, put an angle finder under a flat spot on your knuckle. This specification varies, but generally should be between 4 and 8 degrees back (with the upper ball joint sitting just behind the lower ball joint). Caster can be adjusted with shims on leaf sprung Jeeps and with cam bolts or adjustable control arms on linked Jeeps.
If you or someone who used to own your Jeep thought it was a good idea to catch some sweet air, you may have yourself (or the previous owner) to blame for your death wobble. Stock Jeep axles are not so good at absorbing the shock from massive air time. The result of catching air is a bent axle. This usually leads to leaks and added camber to the front tires. Does excess camber definitively cause death wobble? Nope, but it certainly does not help the situation much. Add in one or two of the other issues laid out here, and your Jeep probably has the shakes.
Loose Leaf Spring Bushings and Bolts
Generally speaking Jeeps with leaf spring suspensions don’t get death wobble as frequently as the newer linked-style Jeeps, but that is not to say that it does not happen. Death wobble can come from loose leaf spring mounting bolts, worn out bushings, bent shackles, bent main leafs, worn ball joints or kingpin bearings, and broken or bent leaf spring centering pins. The best way to check these parts is to look at them, checking for any unexpected side-to-side movement or odd bends. Sometimes discovering a broken leaf spring centerpin can only be done with some disassembly. Find a bent main leaf? Are your shackles leaning to one side? Do your leaf spring or shackle bushings look like cauliflower? If so, replace them.
Unitbearings or Wheel Bearings
If you perform the twelve, six, three, and nine o’clock tests as outlined above and the wheel moves in either or both directions but the ball joints and tie-rod ends are good, then you may have a worn out unitbearing or loose or bad wheel bearings. What should you do? Replace them. We always look for quality wheel bearings and races like those made by Timken, pack them properly, and follow the correct inner and outer spindle-nut tightening sequence.
Many automotive “experts” will immediately recommend a steering stabilizer to cure death wobble. Here’s some bad news for you and for them that they will never accept. Adding a steering stabilizer is just a Band-Aid fix for death wobble. Sure it might prevent the shakes…for a while, but honestly adding a dampening unit to your steering system is not solving the problem it’s only masking the problem. The real problem is something else entirely. Adding a steering stabilizer may help prevent death wobble, but what if the stabilizer springs a leak (pictured), gets dented, falls off, or the other problem that is causing the death wobble becomes too big for the stabilizer to overcome?
Control Arm/Track Bar Bushings, Loose Bolts, Wallowed Out Mounting Points, and/or Bent Components
It’s a fact, components wear out. This happens to factory rubber control arm and track bar bushings, Johnny Joints, polyurethane bushings and even the venerable rod end. Why? Well, because you use your Jeep either on-road, off- or both. Add in any hard hit bumps, rockcrawling, flexing, jumping and so on and things can get loose or bend. The fact is loose control arm or track bar bushings can contribute to death wobble. Bent, or loose bolts, wallowed out mounting holes, and bent control arms can also contribute to your Jeep catching the shakes. To prevent this, keep an eye on your control arms and track bar. The easiest way to find worn track bar bushings or loose track bar bolts is to look at your steering while a buddy alternatingly turns right and left. Hear a pop or a thump? That’s probably a worn out control arm or track bar bushing. To see if something is bent, look at it. Your eye is a pretty good judge of straightness. If that won’t cut it hold a piece of aluminum L-channel against the control arm to see a bend.
Large Out of Balance Tires, Beadlocks, Mud on the Wheels
One of the most overlooked causes or contributors to death wobble are large unbalanced tires and wheels. Did you just huck your Jeep into a big mud hole and then park it? Then you probably have several ounces or pounds of mud dried on one side of the inside of your wheel—that’s a problem. To cure or help cure this, wash off the mud. Are you sure that your wheels are clean, but it’s been years since your bias-ply tires with huge chunked or worn lugs were balanced? Have them rebalanced. We always try to run the tires with the least amount of balance weight on the front axle. Put those barely balanced, mostly worn-out bias-plys on the rear axle. If this does not work because your tires are not balanceable (we once had a tire guy tell us the balance machine called for three pounds on one wheel), it’s time to buy a trailer or new tires.
Bent Wheels, Rotor Retaining Clips
Remember that curb you “rubbed” while checking Facebook while driving? Bad Jeeper! Put that phone down and drive! Remember bashing your wheels on that rock on the trail? Remember when that little old lady hit your Jeep with her land yacht? Yeah, a bent front wheel can also cause or contribute to death wobble. The solution is to get a new wheel that is straight. We have also heard of Jeepers adding aftermarket wheels without removing the star clips that retain the brake rotors on the wheel studs. The aftermarket wheels don’t have a provision for these clips, and the clips cause the wheel to not mount on the brake rotor flush. This causes the wheel to spin with a wobble that can cause or contribute to causing death wobble. The fix? It’s easy, remove the spring clips.