How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask eauto Your Own Question
eauto
eauto, The Car Guy
Category: Jeep
Satisfied Customers: 15062
Experience:  ase mechanic 16 Plus years in the field
6149662
Type Your Jeep Question Here...
eauto is online now
A new question is answered every 9 seconds

I have a 2007 jeep wrangler with 100 k. From time to time

Customer Question

I have a 2007 jeep wrangler with 100 k . From time to time when I go over a bump or the entrance on a bridge ramp periodically the front will go into a convulsion like shaking or like I have a flat tire. I have had the Jeep serviced three time for the problem and basically replaced the whole front end. The problem still exists from time to time. When it happens the first instinct is to slow down then when I get over the sudden shock and resume driving its ok again. So right now it is in the garage and they tell me they can't find anything wrong. I think it is a bit dangerous. Can you advise me thanks Ron
Submitted: 10 months ago.
Category: Jeep
Expert:  eauto replied 10 months ago.

is the suspension stock?

Customer: replied 10 months ago.
All three shocks were replaced
Expert:  eauto replied 10 months ago.

Death Wobble is the shaking that happens when the front end components of your Jeep end up reacting to, or fighting each other - the end result is a violent shaking of the wheel, the Jeep itself shaking like crazy, and you eventually needing new pair of shorts. Death wobble is most commonly seen in Jeeps that have just been lifted, but can also be found in stock Jeeps.

There are two aspects that contribute to make death wobble. First something to begins to wobble, like a tire imbalance or hitting a pothole or bump in the road. The second aspect is generally a loose or worn part that allows the minor wobble to escalate into full-blown death wobble.

Toe-in, caster setting, and tire balance all help contribute to the beginning of a wobble. Loose/worn parts like the front track bar, steering, and control arm bushings contribute to the second phase, when the wobble is exaggerated into the death wobble. If they cant find it take it to a good suspension shop something I worn or loose

Customer: replied 10 months ago.
I really appreciate your time. When I first had the trouble I researched and got that answer about death wobble and replaced all parts. The problem still exist is there any thing else you could suggest.It is at the garage and they say they can find anything wrong or can't duplicate the problem
Expert:  eauto replied 10 months ago.

all parts what have you replaced?

Customer: replied 10 months ago.
the whole front end ball joint shocks, u joints with main torsion bar ( i think that's the name the full bar that goes from wheel to wheel with u joints attached). I haven't got the list right in front of me but most everything I am into for over 4 k
Expert:  eauto replied 10 months ago.

did they replace every tie rod and the steering stabilizer?

Customer: replied 10 months ago.
as far as I know they did . They did the wheel aliment and it showed to be good
Expert:  eauto replied 10 months ago.

a slightly loose front end part or worn steering stabilizer is generally the culprit. I strongly suggest another shop double checking the steering linkage..the shop is missing something

Expert:  eauto replied 10 months ago.

First, the tie rod (green) has ends that attach to a knuckle on each side. As you could imagine, if either ends of the tie rod were broken or bad, that could be a culprit for a shimmy (not Death Wobble). A common place to damage the tie rod is on the driver's side at the adjusting sleeve (in the picture, just to the right of the red swaybar link). That sleeve (maybe not the correct term for it, but you can see what I am talking about) allows the width of the tie rod to be expanded or contracted. There are threads on that end that can be damaged, causing play on that driver's side and allow an up and down, or circular play movement. Again, this would cause a shimmy, not Death Wobble.

Next, look at the drag lin (purple). On one end, it attaches to the pitman arm (lavender), that attaches to the steering gear box. On the other end, the drag link attaches to the passenger side knuckle. When you turn your steering wheel, a shaft turns that goes to the steering gear box. The steering gear box turns the pitman arm, and the pitman arm pushes or pulls the drag link, which pushes or pulls the knuckle. Your steering wheel is straitened by loosening the two nuts on the sleeve/turnbuckle on the drag link and rotating the sleeve/turnbuckle to lengthen or contract the length of the drag link. If either end of the drag link is damaged, this would cause a wobble or shimmy, but not Death Wobble.

Next, look at the trackbar (aqua). It attaches to a bracket on the frame on the driver's side and to the axle on the passenger side. The purpose of the trackbar is to center the axle on the frame. With the axle centered on the frame, it provides some resistance to the steering system to allow you to turn. If there was no trackbar and you turned the steering, the whole front frame would shift. As a result, there is significant force applied to the trackbar in driving and steering.

Now, imagine that the bolts that hold the trackbar are loose in their bolt holes, or that the bolt holes are wallowed out (oval), or that the bushings at the trackbar ends are damaged, or that the bracket at the axle side has come loose because the weld has broken, or that the bushings are all twisted up because the rig has been lifted without the installer loosening the bolts and then retightened them at the new ride height. All these things would allow play in the front trackbar. When you steer or go around a corner, these loose or broken things would allow the axle to shake or slide side to side. If you hit a bump in the road, it could knock the trackbar towards the driver's side. Then, the rest of the suspension (springs, etc.) would try to bring the trackbar back to the passenger side. If you were going at any sort of speed, you could develop a kind of harmonic resonance as the axle more and more violently slide/rocked/shaked from side to side. It would feel like your whole front end was being voilently torn apart. You would have to bring your vehicle to a complete standstill to stop the harmonic resonance. This is Death Wobble.

Even one incident of violent Death Wobble related to the front trackbar can cause significant damage. The voilent harmonic resonance of the back and forth shaking is more than the trackbar bushings, bolt holes, and brackets are designed to handle. A severe Death Wobble occurance can crack or break the welds on the axle side trackbar bracket, or the bolt can wallow out the bolt hole in the bracket, or the bushing can be permanently damaged.

This is the most common source of Death Wobble because inexperienced installers either do not remove the bolt from the trackbar when they install a lift--leaving the bushing pinched in the bracket and bound up, or they do not properly torque the bolts after the lift has been installed with the tires on and the full weight of the vehicle on the ground at ride height, or (maybe the most common) they do not retorque the trackbar bolts after the first 50 miles, after every heavy wheeling trip, and at every oil change interval.

Next, look at the lower control arms (purple) and the upper control arms (light blue). In the picture, they are aftermarket arms with a heim joint on one end. However, the stock control arms have a rubber bushing at each end. When the control arms are properly torqued, the bushing is somewhat pinched in the mounting brackets on the axle and the frame. Sometimes, an installer will make the mistake of not loosening the bolts for the control arms when they install a lift. What happens sometimes is they really bind up the bushings because they are pinched/sandwiched at stock ride height, but then forced to the new lifted ride height. These bound up bushings can cause weird handling, bushing failure, and lead to Death Wobble. The proper way is to loosen the bolts, install the lift, reinstall the wheels so the suspension and jeep are at the new ride height, rock the vehicle/suspension back and forth and side to side, then re-torque the bolts to spec, then after 50 miles re-torque them to spec, then after every oil change or very heavy wheeling trip re-torque them to spec.

Improperly balanced tires, too much air in tires, bent wheels, improperly installed wheel spacers, bad tires(with separated plys), and poor alignment specs (caster, camber, and not enough toe-in) can cause wobbles and shimmies that lead to Death Wobble. However, these precipitate Death Wobble, but they are not the cause of Death Wobble.
Although not specifically identified in the picture, the ball joints that are at the top and bottom of each knuckle where it attaches to the axle C can go bad. Bad ball joints can cause shimmies, wobbles, but usually not full on Death Wobble.

Next, allthough not identified in the picture, the unit bearings can go bad and be a cause of shimmy and wobble, but not Death Wobble.

Hope this helps--assuming you read it all.

Death Wobble is no mystery.

The reason that the steering stabilizer masks it is that it can absorb some of the side to side voilent harmonics of a loose trackbar or damaged mounts. However, this masking is dangerous because it will not prevent the eventual failure of trackbar bracket welds and bolt holes from trackbar Death Wobble.

It is extremely important to immediately diagnose and fix Death Wobble.

Even one episode of DW can damage other components.

Multiple episodes of DW are almost guaranteed to damage other components.

Multiple episodes will often damage your:

  • ball joint
    • tie rod ends--including the adjusting sleeve end on the driver side
      • trackbar bushings
        • trackbar bracket bolt holes
          • steering sector shaft (where the pitman arm attaches to the steering box)
            • steering stabilizer
              • front lower control arm bracket bolt holes
                • unit bearings
                  • trackbar bracket welds
                    • drag link ends
                    Hellbound13 is an example of a member who with 5-6 episodes of trackbar related DW on a stock jeep ended up "chasing his tail" for many, many months. He ended up replacing almost everything in the above list--sometimes more than once.

                    Without repairing/replacing everything