“Death Wobble”

“Death Wobble”©

By Jerry Smith

The dreaded “Death Wobble”.  If you have ever experienced one, we don’t have to tell you it’s one of the scariest experiences you’ll ever have.  If you’re still a Death Wobble “virgin”, count your lucky stars!

What Is A Death Wobble?

You are driving down a street or even out on the open highway cruising along like usual.  Your speed could be anywhere between 30 and 85 mph.  (More often than not, it will happen around 35 to 50 MPH).  Your vehicle hits a very small bump or depression.  One so small, you probably never even saw it.  (click here or go to https://www.youtube.com/watch?v=vwiv23dLhMY  to see a video of a death wobble)

It could have been something as simple as where the pavement changes as you cross a bridge approach or departure.  Nothing that looks sinister.  Manhole covers are often the triggers.

From out of nowhere, your steering wheel begins shaking violently back and forth so hard you can’t hold it still no matter how hard you try.  You cannot turn.  The front of the vehicle feels like it will shake apart any second.

Your only recourse is to slow down… as fast as possible!  That, by the way, is the only known “safe” way to stop a Death Wobble.  We have read of people being able to “drive through it”, but there’s never been any confirmation of that.

This phenomenon will catch you off guard.  If you are lucky, the first Death Wobble will be of the “light-duty” kind.  Consider this to be a warning of bad things to come if you don’t get it repaired NOW!!

Any shimmy that starts all of the sudden… from no shimmy to any shimmy, take it seriously.  Once in a while, you will receive this little warning if you are lucky.  Most of us don’t get a warning.  We go from normal to totally out of control in a microsecond.  That’s the way a Death Wobble works.

What causes a Death Wobble?

** The experiences talked of here are mostly related to Jeep Wranglers.  Other experiences may vary, though not by much**

That question causes “fear” in even the best of auto repair shops.  Most shops won’t know.   The vast majorities of them are not experienced with a Death Wobble and will have a devil of a time repairing it. 

Even a shop full of experienced technicians will often have their hands full.  This is not an “easy fix” very often.  As a consumer with Death Wobble, you will be convinced the shop is incompetent before it is over.  You may be right in this particular instance.  But before you decide, give them a lot of rope to hang themselves.  They may be very competent in most repairs, just not Death Wobble.

Most shops will have “some ideas” of what to do.  Others will just be experimenting.  One thing you may want to ask is “have you repaired any other Wranglers with Death Wobble?”  That is about the only way you will know if they are “experimenting” on yours.

Finding a shop that specializes in suspension and alignments would be your best choice.  They will need skills in those areas well above the average.

When looking for a shop, if the first thing they ask is when you had your tires balanced, just turn around and walk away.  Unless your tires were just installed, that won’t have anything to do with your problem.

Imbalanced or cupped tires can be the pressure on the trigger that starts a Death Wobble, but they are NOT the cause.  **(Read that about three times)**

If your steering and suspension components are all in good working condition, tires… no matter what their condition, cannot cause Death Wobble!

A Death Wobble is seldom a “this is your problem” type of repair.  It won’t be that simple.  The exception will be if your track bar end on the frame side is really worn.  That is usually the first place to look.

The vast majority of the time, it will be a combination of several slightly worn parts adding together to cause the entire problem.

Those parts will include things like the ball joints, tie rod ends, drag link ends, the track bar ends, control arm ends, and occasionally the need for an alignment and/or toe adjustment to be sure the other items are working properly.

Only if the Death Wobble was one of the light duty “warning” types will the alignment help.  It may “hide” the wobble for a while, but it will just be temporary.

One “trick” that will sometimes “mask” the problem will be to either add or replace the steering damper.  This will not cure the problem… just hide it temporarily if at all.

Lifted vehicles are maybe slightly more prone to the Death Wobble.  The reason for this is the change in all the angles of your steering and suspension.  Most will have a much more acute angle than stock parts would have. 

If you have just recently lifted your rig, an alignment should have been done.  If not, when they do it, ask them to make double sure the ball joints and all the steering ends are in very good condition, not “just OK”.    Small wear in each, when added together, make for a lot of wear as far as a suspension goes.

Be prepared to have several new parts installed.  The first will probably be the track bar ends. (This will require a new track bar in most cases) Next will likely be the ball joints and then the steering linkage ends.  After that, the control arm ends.  This is by no means an “always” order of things, but experience with several of these has shown this to be “normal” if there is such a thing.

How to properly check your steering

The following procedure is the best way to begin the inspection of your steering.  Most well-trained technicians will know how to check ball joints for wear, but the following may be new to most of them.

Have someone inside the Jeep rock the steering wheel back and forth enough to make the steering move the tires slightly.  This will load and unload the steering components. 

(BEFORE DOING THE FOLLOWING, MAKE SURE YOUR FINGERS ARE NOT GOING TO BE PINCHED OR CUT).

Both visual and touch or “feel” inspections should be done to each joint (tie rod ends, drag link ends, track bar ends, ball joints, and the control arm ends… both upper and lower).  Sometimes you can “feel” what you can’t see.  Be very critical of any movement caused by wear.

When inspecting the track bar, there are some special things to look for.  First, take a wrench and check the bolt on the axle end mount for tightness.  If it is even a little bit loose, it is a very good idea to remove it and check the bolt holes in the mount for elongation.  This is normally hidden from view and is easily overlooked.

You can also loosen the nut and watch the bolt for lateral movement as the pressure changes from one direction to the other as someone violently moves the bumper up and down to see if it moves or the steering is rocked side to side.

A better way to check for this is to observe the bolt as someone moves the steering wheel back and forth loading and unloading the pressure on the track bar mount bolt.  Movement here is a prime source of the Death Wobble.

Next, check the frame end of the track bar.  This one is often best done by feel as you can often feel movement you cannot see.  Just be careful not to get your fingers pinched. 

Often, the tapered stud (on the TJ) will move in the bore of the hanging tower as well as the ball joint can be worn.  More often it is the stud in the bore moving. 

Often, (on the TJ) you will want to check the torque on the nut with the cotter pin.  This is a taper fit stud that loosens from use.  The stud stretches and then the tapered bore begins to wallow out.

You’ll need to remove the cotter pin and torque the nut to specs.  Don’t forget the cotter pin when done.

Watch for twisting in the main frame while checking this as well.  The leverage on the tower can overcome the frame and weaken it over time.

Next check the steering gear for movement on the frame and in the gearbox.  Once in a while, a steering box will loosen on the frame and move.

Check the control arm ends for movement.  Here again, like the axle end on the track bar, make sure the mount bolt holes are not elongated as well as checking for wear in the bushings.  This will require loosening the nut(s) on the control arms as a minimum.  You may want to remove the bolt to check the bore in the mounts for being tight and round… not elongated.

Note:  If you do loosen the control arm nut and/or remove the bolt, put the full weight of the vehicle on the suspension BEFORE torquing the nuts.  Otherwise, the bushings will be twisted out of shape when the load is reapplied and premature wear will occur.

Trying to move the control arm with a pry bar between the mount and the control arm will usually show wear if there is any.

Make sure the wheel bearings have the proper preload and then lift the front tires off the ground enough to be able to rotate the tire and wheel.  Check the wheels for run-out (make sure they aren’t bent).  You might want to check the brake rotors while doing this too.

Look for cupping or other abnormal wear patterns in the tire tread.  “Reading” tire wear patterns can tell you a lot about a suspension and alignment with a little experience.  A good alignment tech can do this.

While the tires are up is a good time to check the ball joints for vertical wear.  There should be very little or no vertical movement in the ball joint.

This is a lot to check for, but if you don’t, expect to repeat it sooner than later.

When replacing any parts, especially if you’re Jeep is lifted, if you can afford them, upgrade to the most heavy duty and adjustable you can find.  The best ball joints are made with an adjustable “eccentric” feature that allows you to adjust the camber.  The ability to adjust everything is a great benefit to “dialing in” your steering to make your rig drive like a new one or even better.

While doing your road tests it is a very good idea to remove or at least disconnect the Steering Stabilizer (damper).  The SS will often mask your true problem and make recreating a Death Wobble harder. 

You want to duplicate the problem, not cover it up until you’re out driving along and it surprises you in a bad way.

You may be warned ahead of time unless you have all of these items replaced all up front, there is a reasonable chance you will get your vehicle out of the shop “repaired and ready to go”, and the problem will persist.  Things will go well for a while and all of a sudden, it will be back! 

If a technician is really good, they may know of a particular street where they can “make it happen” more often than not.  (Very, very few will have this much experience)  But there is no guarantee about this.  You normally can’t just go out and create a Death Wobble at will unless it is a severe problem.

In Grand Junction, I know of such a stretch of road where I have experienced the Death Wobble many times.  (They’re still not fun).  With that kind of background, I can tell pretty much when a vehicle is really “repaired”, but I still will not guarantee that until most or all joints are replaced.

OK.  We’ve replaced all suspect parts… what’s next?

It’s time to go to the alignment shop.  Here is something not many know about lifted Jeeps that can make a big difference in how your Jeep will perform.

As you lift a Jeep, the angles on the steering and suspension change.  This is not always good.  One trick that has been learned over time is to adjust the caster a little toward the negative as the lift increases. 

For instance, a Jeep TJ with a 4” lift should have the caster at +3 °, + or - 1°.  (that is: +3 degrees – Plus or Minus 1 degree). The alignment tech may want to set it at +7° because the specs show that is where it should be.  That is true for a stock height suspension. 

A lifted suspension is not stock… so you may get some argument from some alignment shops.  It’s up to YOU to educate them or take it to another shop.  This may require adjustable control arms… but they are a must.

Doing this will also take vibration out of your front driveline when done properly.

For a little more proof of this and a very good education in aligning a Jeep suspension, go to;   http://www.teraflex.biz/news/cat/teraflex-video/post/teraflex-jeep-tj-alignment-training-part-1/ where you will see a three-part video of a Jeep with an upper-end suspension being aligned.  This suspension won’t be exactly like yours, but the basics are still the same.  And who would know how to properly set up a suspension than the manufacturer of one of the premier Jeep suspensions?  Trust me; the time spent watching this will be rewarded.

Occasionally, your toe-in/out will be “tweaked” while driving in the larger rocks or even in extremely rough conditions.  A bent tie rod is often the culprit.  Toe-in is critical when related to Death Wobble and you want it close to perfect.

I hope you never have to live through this Death Wobble problem, but if you begin lifting a rig, don’t be surprised if Death Wobble rears its ugly head after you get some miles on.  Keeping a good alignment will help… for a while.  But when it is time, the only help for Death Wobble is proper repair. 

Happy Trails to you.

NOTE:  Jerry is a Journeyman Heavy Equipment Mechanic who started as an Alignment Specialist right after 4-years in the Navy.  His Alignment and automotive education came from the Denver Automotive Institute.  In later years, he worked in a 4X4 shop installing suspensions and other accessories.

Copyright 2010 - 2019 Happy Trails 4WD.com  All rights reserved