Death Wobble: Know it, understand it, fix it

[Ole Cowboy]

DW applies only to: ALL CARS, TRUCKS, MOTORCYCLES, SHOPPING CARTS, SOLID axle, independent suspension modes of transportation that was manufactured after 1901.

It is NOT a question of Right or Wrong, it is a question of Newton's 1st and 3rd law of motion: "Newton's first law states that every object will remain at rest or in uniform motion in a straight line unless compelled to change its state by the action of an external force. ... The third law states that for every action (force) there is an equal and opposite reaction."

1) If it is attached to the front suspension it plays a role in DW.

2 The following are generally the things you want to look in no order:

Track bar, bushings, and mounts

Steering stabilizer

Ball joint wear

Soft or worn shock

Ball joints

Rubber bushings

Tie rod ENDS being excessively worn

Tire Pressure, too low or unbalanced

Alignment and wheel balance should ALWAYS be in adjustment

Toe-in OEM specs and caster adjusted and compensated for tire size

Lower/upper control arms adjustment and bushings

Yes, anything and everything hanging under the frame of the front end

3) I recommend setting your own caster and toe because MOST shops will ONLY set to factory specs, which is fine if you are running a factory setup. But lifts, large tires etc can and will alter your toe-caster setting.

4) When you add lift or larger diameter tires you alter your caster. Toe rarely changes unless you "Y" steering setup, then when you add lift, your toe does change.

The ROOT cause of DW is an out of balance condition along with worn components. Often it is initiated when you drive over railroad tracks or a "crease" in the road from the contraction of road surface materials. The hitting of a manhole cover or pothole are other examples.

What takes place is the impact forces the tire backward and to the left or right unless you were to hit it exactly dead on. The L/R motion brings with it the OTHER side (tire). As you move forward the suspension tries to straighten out the tires. BUT Newton's laws of motion begin to interfere.

When an impact causes one tire to move L or R, then the other tires are forced to move along with it, but it exerts its own force, Newton’s 1st law of motion: "Every object continues in its state of rest or of uniform motion in a straight line, unless it is compelled to change that state by forces impressed upon it. " As you might surmise, all hell is fixing to break loose. What the automakers and engineers do is add a steering stabilizer to absorb, slow down and mitigate the violent continuing reactions…better known as DW. The SS is NOT a band-aid, it’s an integral component of your steering and suspension. It is also your First Responder to DW.

Bottom line. Bigger tires, out of alignment, worn components, and road hazards can all wreak havoc. Here I will borrow from my world of software engineering coding and Economic of money flow; the “multiplier effect”. And, if you have ever played any pool and “broke” you can plainly see it when the cue ball hits the pile of racked balls…that is the multiplier effect in action or if you have ever written a line of bad code in a software program, how that rolls thru the system to create other problems. This is what happens when an impact takes place and something in your suspension is out of whack.

There is no one singular case you can blame every time, but rather it is the sum of various components. It is this very thing that makes curing DW so elusive.

Coming soon:

Toe/Caster Understand it, DIY better than than the shops do.

DW How I Fixed it and tips on how you can too

Sponsored

 

[Ole Cowboy]

Getting your Jeep aligned can often be more than a headache. We often hear: 'Tires are too large for our machine', 'we don’t do lifted Jeeps', and 'we do not know how to adjust control arms', etc are just some of the stories.

Adjusting caster on our Jeep's is not only simple, but you can do it yourself in your driveway.

Caster:

The angle between the vehicle's steering axis and a vertical line, as viewed from the side, measured in degrees.

It is CRITICAL that the Angle Finder [available from Sears, Home Depot, ACE, about $10 or less] be ALIGNED and parallel lengthwise with the Jeep frame and wheels.

TIP:

You MUST be looking at the angle finder (AF) straight on to get an accurate reading. Try looking at it and moving your head slightly to the left and right of the angle finder. You will see it shift back and forth, this will help you identify the exact angle. Might want to practice by setting your angle finder on any flat surface that you can easily move back and forth while looking at it.

BETTER WAY:

Discovered this Digital Multifunction Torpedo Level Mdl48295, at Sears. It reads to an accuracy of .1 and displays to .1 degree. It does several other things such as a lit screen and what is really COOL is the display automatically flips to read correctly when you turn it upside down.

It has a powerful magnet on the bottom and will provide some very accurate readings for Caster measurements over the Home Depot angle finder.

http://www.searshometownstores.com/product/Craftsman-48295-Digital-Torpedo-Level

Note:

Alignment machines can get far more accurate readings. Most will at least give 2 decimals points, some can do even 3, 4.589 for example. Looks impressive, but its most likely a waste. Adjustment ability is only about a half-degree max in most cases.

Bottom line is you can get just as good results as the alignment shop. I would not recommend using your driveway unless you know it is level on level ground, your garage floor might be a better place unless it has also been sloped for water runoff.

Set Caster (using adjustable upper/lower control arms):

To DECREASE CASTER ( - ):

Lengthen the upper control arms and or shorten the lower.

To INCREASE CASTER ( + ):

Shorten the upper control arms and or lengthen the lower.

Positive Caster:

Next time you see a motorcycle, look at the way the front wheel is kicked out in front of the bike this is a positive caster.

Negative Caster:

Shopping cart with floppy wheel, and wheels are behind the vertical, this is a negative caster.

Cross Caster:

The difference in side-to-side between caster settings. More than half a degree difference may cause a steering pull toward the side with the least caster. Caster on the left front wheel is sometimes decreased to compensate for high road crown.

1) Park Jeep on a flat hard surface with wheels straight and parallel to the frame

2) Place AF on bottom of knuckle at outer end of front axle, insure the AF is parallel with the direction of the Jeep wheels and frame

3) Write down angle

4) Do same on opposite side

5) Write down angle

6) Remove end of control arm that you can adjust and count each full turn. For a starter, do 4 or 6 full turns, replace control arm and measure the change in angle. Example: 6 full turns resulted in 3 degrees. Therefore, each full turn = 1/2 degree, each 1/2 turn = 1/4 degree. Applies to JKS 18 TPI Control Arms, but most will be close

7) Now adjust your control arms to obtain the desired caster settings. Somewhere between, about 3.5 and 8 degrees depending upon various factors such as lift, size of tire etc

8) Now do a check of your front pinion angle. Bear in mind that front pinion angle is more important than caster

9) Road test. During the road test, turn the vehicle both the left and right. Insure the steering wheel returns to the center position unassisted. If steering wheel does not return to the center position, a too low caster or negative angle is the probable cause

10) Ensure all is tight and you are almost finished

If suspension clearances are tight or there is a issue of touching then you can work with just the uppers, the lowers or split and do both

If you do not have adjustable CA’s, get the adjustable cam bolts available from DC Jeep.

11) Setting Toe: Check that toe is about 1/8-inch +/- 1/16-inch, toe in. When doing alignments, toe is always the last setting.

A) Should you spend your bucks to get an alignment? No, I can not see any reason to at all. While their 'belt-fed, laser aimed, water-cooled' alignment machine will spew out corrections down the micro level...fact is none of that works much better than doing it yourself.

WHY? You are dealing with: 2 tie rod ends, 4 ball joints and a rubber tire. All of this has give, even if brand new, that is the way its made. If you get and you can get accuracy to within 1/16th of an inch, you will do as well as any shop does. (NOTE: They use rotating pads to keep the tire from scrubbing and rebounding. Putting the axles on jack stands is a good idea

B) Setting the toe: Viewing the tire(s) from the side some things are very critical. Know the keys and success will be the result.

key: where you measure on the front side of the tires NEEDS to be the same exact spot (height from the ground) on all 4 tires.

key: measure as high UP on the tire as you can get at on front, back and the same place on the other tire.

key: the OPTIMAL point is the max forward leading and rear trailing point of the tire. Like this: ' >0< ' WHY? as you go DOWN and around the tire the front and rear points get closer together and in order to get you 1/8th toe in (+/- 1/16th in) you adjustments have to get larger meaning the wheel has to be moved more in order to get the 1/8th in difference.

After you have set your toe, drove it and then rechecked it, YES it will likely change some, but about 1/16th is within tolerance.

TIP: Now take a tape measure and measure from 1 grease fitting to the other grease fitting on your tie rod. Using a 'silver' perm marker write it down on any flat surface underneath and annotate whether or not you measured from the outside or inside of the grease fitting. Ever need to remove or replace your tie road or get a bent tie rod then just look at your measurement between the grease fittings and use that as a starting point. It should be VERY close.

TIP: Remember you need to loosen BOTH jam nuts on the tie rod and on the drag link then turn the tie rod/drag link, then tighten your jam nuts. You want to note the number of visible threads and try to get the tie rod ends at the same depth on each side.

Those are the principles or keys if you will that will ensure you get as good a toe in as the shop does.


Readers question, from 'RockPig': When the angle finder is attached to the bottom of the knuckle, the needle should be to the right of the 0 correct, and my Steering wheel will not return to center easily after a turn, what do you suggest?

Looking at your angle meter: If the front LEFT tire is kicked out (forward towards the front of the car) this results in a + caster the needle will be to the RIGHT of the 0 degree mark.

Conversely (note, this is done while laying under your Jeep)

Looking at your angle meter: If the front RIGHT tire is kicked out (forward towards the front of the car) this results In a + caster, the needle will be to the LEFT of the 0 degree mark.

That said, REMEMBER that the NEEDLE in fact is ALWAYS pointing UP as its counterweighted and meant to do so. It is the angle meter that is moving. If your looks like the ones above then it is round. THINK of it as the tire. Since you want to obtain + caster then the tire/angle meter must rotate forward to the front of the vehicle.

TIP: Hold the angle meter in hour hand and NOT looking at the needle, rotate the angle meter to give + caster, thinking of it as a wheel, now look at the needle.

What to set the caster at:

As we move to larger and larger tire sizes we inherently alter the caster due to the larger tires footprint. Large tires give you more positive caster. To compensate, we need a new caster setting to offset the larger tires. Reduce your caster setting by about -.5 degrees as you go up in each tire size. If OEM is 7 degrees caster and you add 37's try -5 to -6 degrees. The reason caster increases as you put on larger tires is because the tire contact patch is larger (wider and longer).

 

[Ole Cowboy]

I have experienced DW on my Harley, my Corvette, and have been driving Jeeps since the 60's. I have worked to mitigate it as a mechanic and as a Off Road shop owner. YES I can and have fixed it.

Here is how bad it can get: Cracked track bar frame support, look at cut off frame support sitting on the tire and you will see a piece of paper inserted into the crack.

To fix I cut off the old track bar frame support and I built a new track bar using a spherical double shear set up:

I welded it to the frame and dropped it down to be a parallel connection to the axle vs the typical angled connect.

Parallel front suspension is a big plus to solving DW on highly modified vehicles. NOTE in the pic above that I cut off and moved my Steering box. Below you see parallel: Track bar, tie rod, Steering Stabilizer, and Pitman arm connection, note the parallel to the axle.

Short of doing this which is aimed at modified Jeeps, but you and you OEM stockers have got plenty of options:

Stronger Steering Stabilizer, even with OEM tires DW can show up.

Be FANTICAL about equal air pressure and alignment of your front end. Doing those 2 will put you way out front in beating the Devil DW.

 

[Ole Cowboy]

Trip Report:

While out in Pomona, Ca attending the Off Road Expo I was driving I 10 which is in dire need of repair. The road is rougher than a Nyquil hangover and no one's friend, Death Wobble, is trying to hitch a ride with me at about 70 mph. Of course, it picked a great time to do it as I was lifting a cup of near-boiling coffee to my lips.

Suddenly I find myself trying to steer, dodge boiling coffee and traffic at the same time. I’ve got 7 or 8 cars around me that are watching the Jeep Rubicon do the Death Wobble 2-step, coffee is everywhere but mostly on the inside of the windshield, my lower lip and between my legs which is causing me to lift out of my seat.

Finally, I get the Jeep settled down enough to pull over in the wish I wasn’t here lane. I get out to do an inspection and of course, normal cars are whizzing by only inches from my burnt body. Now I know how the lady who spilled her Mc Donalds coffee felt, wonder if I can sue myself??? At least the wind is making my crotch and lower lip feel a little better.

Turning the Jeep around at the next exit and heading back to the motel to change clothes, and try to figure out what to do about my lower lip. I also need to think about what I can tell my wife that she will believe about why I have a scalded crotch. Maybe I will tell her its some California HOTTIE I pick up!

The genesis of my problem is in the frame side of my track bar mount. I run an OEM track bar and the weak side is the tie rod end that affixes to the OEM “C” mount welded to the frame. The small tie rod end is no doubt in a constant struggle to keep the Dynatrac ProRock 60, 37 MTRs and Walker Evans bead locks running on the straight and narrow. Rapid wear in the OEM tie rod end is clearly expected. Gotta apply a FIX!

 

[Alaska-HWY JK]

So the Mopar 2” lift with non adjustable control arms might not be a great idea?
Unless you use cam bolts which you shouldn’t have to if replacing a set of control arms?

 

[Renegade]

So the Mopar 2” lift with non adjustable control arms might not be a great idea?
Unless you use cam bolts which you shouldn’t have to if replacing a set of control arms?

The control arms in the Mopar 2” lift are about 1/4” longer than stock, and SHOULD put a Gladiator (or JL) back into the proper caster range as long as no other modifications are made. I’m sure DW exists somewhere in the JT/JL world, but I am (so far) impressed with the suspension integrity. All he wrote is solid analysis of the issue and should be helpful if it is encountered. I’ve experienced it on a few Jeeps, and it is serious stuff.

 

[Gobi Wan K]

I use one like this when I am building or setting up axles.
Calculated Industries 7434 AccuMASTER 2-in 1 Magnetic Digital Level and Angle Finder / Inclinometer / Bevel Gauge, Latest MEMs Technology, Certified IP54 Dust and Water Resistant https://www.amazon.com/dp/B0148M7P4O/ref=cm_sw_r_cp_apa_i_zTAzDb1Q4TVVK

It is magnetic and you can zero it if you are working in your driveway.
Most good kits on the market should come with control arms that will maintain your caster angle. But it is worth checking before and after a lift. You really have no need for an alignment shop with a straight axle Jeep.

 

[LongTimeListener]

I’m sure DW exists somewhere in the JT/JL world, but I am (so far) impressed with the suspension integrity. All he wrote is solid analysis of the issue and should be helpful if it is encountered. I’ve experienced it on a few Jeeps, and it is serious stuff.

Indeed. I had it on my first JK due to a shop that didn’t retighten a lift correctly.

I’ve done all my own work since then. Never had it on my current JK (knock wood) but I’ve been fanatical about trying to prevent it. Grade 8 bolts for all the suspension parts. A track bar reinforcement brace. High quality lift components and regular checks of torque specs.

It’s a lot of work and a healthy amount of money. But DW is real. Experience it once and you’ll have the fear of God put in you.

 

[smess]

OLE COWBOY- THANK YOU!!!!!

I have tried to explain the things that you posted to help people on Forums countless times and the next guy would always say no that's not right blah blah blah.

I can save myself countless hours of posting by referring to this thread.

Best Jeep thread I have ever read, nice to see someone that gets it and can explain it.

To future death wobblers please read this thread, to future lift lit installers who's Jeep drives like shit after please read this thread. to future alignment guys that tell Jeep owners they have solid axles and can only adjust toe read this thread!!

Good night!!

 

[Glady04]

Trip Report:

While out in Pomona, Ca attending the Off Road Expo I was driving I 10 which is in dire need of repair. The road is rougher than a Nyquil hangover and no one's friend, Death Wobble, is trying to hitch a ride with me at about 70 mph. Of course, it picked a great time to do it as I was lifting a cup of near-boiling coffee to my lips.

Suddenly I find myself trying to steer, dodge boiling coffee and traffic at the same time. I’ve got 7 or 8 cars around me that are watching the Jeep Rubicon do the Death Wobble 2-step, coffee is everywhere but mostly on the inside of the windshield, my lower lip and between my legs which is causing me to lift out of my seat.

Finally, I get the Jeep settled down enough to pull over in the wish I wasn’t here lane. I get out to do an inspection and of course, normal cars are whizzing by only inches from my burnt body. Now I know how the lady who spilled her Mc Donalds coffee felt, wonder if I can sue myself??? At least the wind is making my crotch and lower lip feel a little better.

Turning the Jeep around at the next exit and heading back to the motel to change clothes, and try to figure out what to do about my lower lip. I also need to think about what I can tell my wife that she will believe about why I have a scalded crotch. Maybe I will tell her its some California HOTTIE I pick up!

The genesis of my problem is in the frame side of my track bar mount. I run an OEM track bar and the weak side is the tie rod end that affixes to the OEM “C” mount welded to the frame. The small tie rod end is no doubt in a constant struggle to keep the Dynatrac ProRock 60, 37 MTRs and Walker Evans bead locks running on the straight and narrow. Rapid wear in the OEM tie rod end is clearly expected. Gotta apply a FIX!

 

[Glady04]

@Ole Cowboy Do you think a 1.5” leveling spacer kit (Daystar) in the front requires alignment? My steering was a hair out of center, but alignment seems ok. What do you think?

 

[MACulberson]

Great explanation, thank you.

 

[Desert Outlaw]

Very definitive thread relating to Death Wobble!

 

[pkings]

DW applies only to: ALL CARS, TRUCKS, MOTORCYCLES, SHOPPING CARTS, SOLID axle, independent suspension modes of transportation that was manufactured after 1901.

It is NOT a question of Right or Wrong, it is a question of Newton's 1st and 3rd law of motion: "Newton's first law states that every object will remain at rest or in uniform motion in a straight line unless compelled to change its state by the action of an external force. ... The third law states that for every action (force) there is an equal and opposite reaction."

1) If it is attached to the front suspension it plays a role in DW.

2 The following are generally the things you want to look in no order:

Track bar, bushings, and mounts

Steering stabilizer

Ball joint wear

Soft or worn shock

Ball joints

Rubber bushings

Tie rod ENDS being excessively worn

Tire Pressure, too low or unbalanced

Alignment and wheel balance should ALWAYS be in adjustment

Toe-in OEM specs and caster adjusted and compensated for tire size

Lower/upper control arms adjustment and bushings

Yes, anything and everything hanging under the frame of the front end

3) I recommend setting your own caster and toe because MOST shops will ONLY set to factory specs, which is fine if you are running a factory setup. But lifts, large tires etc can and will alter your toe-caster setting.

4) When you add lift or larger diameter tires you alter your caster. Toe rarely changes unless you "Y" steering setup, then when you add lift, your toe does change.

The ROOT cause of DW is an out of balance condition along with worn components. Often it is initiated when you drive over railroad tracks or a "crease" in the road from the contraction of road surface materials. The hitting of a manhole cover or pothole are other examples.

What takes place is the impact forces the tire backward and to the left or right unless you were to hit it exactly dead on. The L/R motion brings with it the OTHER side (tire). As you move forward the suspension tries to straighten out the tires. BUT Newton's laws of motion begin to interfere.

When an impact causes one tire to move L or R, then the other tires are forced to move along with it, but it exerts its own force, Newton’s 1st law of motion: "Every object continues in its state of rest or of uniform motion in a straight line, unless it is compelled to change that state by forces impressed upon it. " As you might surmise, all hell is fixing to break loose. What the automakers and engineers do is add a steering stabilizer to absorb, slow down and mitigate the violent continuing reactions…better known as DW. The SS is NOT a band-aid, it’s an integral component of your steering and suspension. It is also your First Responder to DW.

Bottom line. Bigger tires, out of alignment, worn components, and road hazards can all wreak havoc. Here I will borrow from my world of software engineering coding and Economic of money flow; the “multiplier effect”. And, if you have ever played any pool and “broke” you can plainly see it when the cue ball hits the pile of racked balls…that is the multiplier effect in action or if you have ever written a line of bad code in a software program, how that rolls thru the system to create other problems. This is what happens when an impact takes place and something in your suspension is out of whack.

There is no one singular case you can blame every time, but rather it is the sum of various components. It is this very thing that makes curing DW so elusive.

Coming soon:

Toe/Caster Understand it, DIY better than than the shops do.

DW How I Fixed it and tips on how you can too

This is one of the most informative and well written posts I've seen in a long time

 

[Ole Cowboy]

This is one of the most informative and well written posts I've seen in a long time

Thank you very much. Here is the backstory: Over the years I had DW from time to time and the cure was a new Steering Stabilizer and a rotate/balance of tires. But when I kicked my Jeep up to notches unknown with 37's, full beadlocks and started driving thousands of miles a month hitting trails across the SW from Texas to Cali. I started dealing with hard DW. I must have gone to every shop from Dallas to Phoenix and heard every story on how to solve from adding chrome muffler bearings to adding 4 SS. FACT was NO ONE could solve the problem.

What I also confirmed was there is more misinformation about Jeeps than good info. Most of the comments you will get on forums are from what we called in my Racing days back in the 60's "Bench Racers". These are guys who sit at their bench in the garage posting information and they have never driven a car down a race track, or taken a Jeep beyond the curb other than at Sonic Drive IN. IOW they have no friggen idea. They read the latest issue of WeBeJeeps that some company bought full pages ads to get a write up on their 10 in lift kits. He reads it and then spews his new found knowledge on the forum but does not own, use it or anything else. FYI one of the TOP DOGS in jeepdom back in the TJ days I happened to know him very well, he was considered a GURU...He did not even own a Jeep and when he finally got enough coin to buy a used one he never wheeled it because he did not know how and he would not wheel with anyone because they would learn he knew nothing about Jeeps. He wrote about them, and got LOTS of stuff to test and install. I know because I was one of his testers and I installed stuff on my Jeep then wrote a report and sent it to him so he could publish it.

I won't mention his name, not even sure if he is still active in the Jeep community, have not seen him since my TJ days. He did not have the coin to afford a new Jeep then, certainly not today with their nosebleed prices...

Well I am an engineer and albeit I left the Mech field for Software Engineering I had not forgot how to solve problems.

What I did was crawl under my Jeep and STARE at the front suspension and I was under there most of the day and then it hit me this is how I can solve the problem and I did it, its worked and I put about 60k miles on it past that point with no issues...

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