How to get rid of death wobble

[jeeponthebrain]

So... I changed both tie rod ends, and both drag link ends, and rotated my tires and now have the dreaded "death wobble" at about 20 MPH. It does not happen every time I drive, and is usually caused by hitting a pot hole or rough spot in the road. I have a '91 YJ with a D44 front, spring over, no track bar, AGR hydro assist, 38 swampers on 12 wide steel beadlocks that are not balanced. Suprisingly, I can drive on the freeway at about 60 mph without much vibration, (for a Jeep with 38's) the issue seems to be at low speeds. I have not had an alignment done yet, my guess is I screwed up the toe-in or out. Does anyone have a good solution for "death wobble"?

 

[waynehartwig]

Alignment. More than likely your toe in is off and causing it....

 

[Milner]

Yep, look at toe, but with that heavy of tire/wheel combo, you are likely to always have some issues....I run the same tire/wheel combo with beadlocks and no balance either....It is a lot of wieght to ask of springs/bushing to control (I assume you are still leaf w/o track bars??) If so, replace the spring bushings and maybe put the trac bar back on for street driving.

 

[ihscout2]

Wobble?

If you haven't done it already, re-torque your wheel bearings as well. If there is too much play in them, you can get that oscillation started.

So... I changed my both tie rod ends, and both drag link ends, and rotated my tires and now have the dreaded "death wobble" at about 20 MPH. It does not happen every time I drive, and is usually caused by hitting a pot hole or rough spot in the road. I have a '91 YJ with a D44 front, 38 swampers on steel beadlocks that are not balanced. Suprisingly, I can drive on the freeway at about 60 mph without much vibration, the issue seems to be at low speeds. I have not had and alignment done yet, My guess is I screwed up the toe-in or out. Does anyone have a good solution for "death wobble"?

 

[78mitsu]

Heavier shock or dual shock will help to control heavy wheel/tire combination. Bad or No Shock can contribute to the problem, no dampening lets the oscillation start and grow in amplitude. - right scott -

 

[leorn]

possibilities

It's a fun mystery, but here are some of the causes I've seen:
1. cracked frame
2. loose steering
3. other loose front end stuff ie tie rod ends, wheel bearings, bushings
4. camber

for mine all I did was tighten the steering box

 

[waynehartwig]

It's a fun mystery, but here are some of the causes I've seen:
1. cracked frame
2. loose steering
3. other loose front end stuff ie tie rod ends, wheel bearings, bushings
4. camber

for mine all I did was tighten the steering box

How could camber cause it? I know toe in will, I can see how caster might, but camber?

Typically dw is caused from a tire lifting off the ground while the other is turned in, causing the truck to shift to opposite side real fast, then the other tire lifts when the other tire makes contact and jerks you back over, speed that up hundred times and you lose control, or hard to keep control. Hard to explain in text form, but it's from being pigeon toed.

Your tie rod could even do it, if it is real flimsy and flexes easyily on the highway, which comes back to the toe in being off.

 

[leorn]

oops wrong c-word

 

[greenjeep]

So would a steering stabalizer work to fix this, or is that just a bandaid for a more serious proplem?

 

[Greg]

So would a steering stabalizer work to fix this, or is that just a bandaid for a more serious proplem?

You got it, that's just a bandage. It's best to just fix the problem, rather than to address the symptoms.


Here's a little bit I wrote a few years ago about fixing DW. This was on my Toyota w/ the toy axle, so there's some info that applies to those. But the general alignment idea is the same.

http://www.rockymountainextreme.com/showpost.php?p=7929&postcount=9

I did another Tape Measure alignment like this on my 4Runner's Dana 44 and it tracks down the road perfectly. Nothing like doing your own alignment!

 

[neagtea]

My 38" bias ply swampers would do the same. I would also check the other stuff like not enough preload on the upper ball joints or if ya have Negative caster

 

[notajeep]

I had the DW's also and I found that my problem was the my shackles (which I had just replaced) were to long with no center support. I sleeved a bolt with some tube to give them some more vertical rigidity (sp).
The second time I had the DW's, (after I checked the shackles) I found that my hi-steer arms were loose.
I also did my own alingment.

 

[waynehartwig]

So would a steering stabalizer work to fix this, or is that just a bandaid for a more serious proplem?

DW is only solved by fixing loose steering components and/or correct alignment. However, those big tires could be causing some of it, and if so, a good ss will resolve it. But yeah, throwing a ss at dw is only addressing a symptom, like Greg said.

An easier way to do the alignment is to find a center line on each front tire, most tires have a groove in the middle and that groove will be in the same spot on both tires. Then measure the distance between the front and rear, making sure you are at the same height as the axle - ie, don't measure the upper portion of the tire in the back, and the lower in the front. Then like Greg said, set it 1/8-1/4 of toe in and your done.

I don't like taking the tires off and attaching steel for a copule of reasons. 1-the full weight is no longer on the suspension and having the full weight on it can change your alignment - especially for you IFS guys. 2-the rotors aren't solidly attached to the wheel hubs, and that can give you false readings.

 

[greenjeep]

An easier way to do the alignment is to find a center line on each front tire, most tires have a groove in the middle and that groove will be in the same spot on both tires. Then measure the distance between the front and rear, making sure you are at the same height as the axle - ie, don't measure the upper portion of the tire in the back, and the lower in the front. Then like Greg said, set it 1/8-1/4 of toe in and your done.

Doing how you said does seem way easier, but it will give a WAY different setting than how Greg suggested. He is setting his tow-in and the rim edge, you're at the tire edge, depending on the size of your sidewall that's a big differance; for my 37s, it like 11". So a 1/4 inch at one point vs. 1/4 inch 11" farther out is going to make the first much less than 1/4 inch. So I guess I'm saying should tow-in be set at rim edge, or tire edge; or am I ready WAY too much into this and it doesn't really matter that much?

Thank you, drive thru

 

[Greg]

...I don't like taking the tires off and attaching steel for a copule of reasons. 1-the full weight is no longer on the suspension and having the full weight on it can change your alignment - especially for you IFS guys. 2-the rotors aren't solidly attached to the wheel hubs, and that can give you false readings.

I know it's easier to do it form the wheel or tire, but I think it's not as accurate. Tires have a lot of runout & wheels can be bent. Measuring off the wheel mounting surface is as accurate as you can get, I bet you'll get more mistakes measuring off the wheels/tire.

#1- If you're getting DW from IFS, you've got far bigger problems to worry about. Besides, we're talking about a solid axle vehicle here.

#2- My Toyota axle, as well as my Dana 44 have the rotors solidly attached. You're not going to get an inaccurate measurement since that's the wheel mounting surface. If it's a Dana 30 or anything else with hanging rotors, just run a few lug nuts down to the rotor & it's no longer an issue.

In my opinion if you're trying to fix a DW problem, take the time to do it right. Pull the wheels, get the measurements right on and get it fixed the first time.

 

[Greg]

Set it at the rim, that's the surface that the specs are supposed to correlate with & is how you're supposed to do a proper alignment.

Doing how you said does seem way easier, but it will give a WAY different setting than how Greg suggested. He is setting his tow-in and the rim edge, you're at the tire edge, depending on the size of your sidewall that's a big differance; for my 37s, it like 11". So a 1/4 inch at one point vs. 1/4 inch 11" farther out is going to make the first much less than 1/4 inch. So I guess I'm saying should tow-in be set at rim edge, or tire edge; or am I ready WAY too much into this and it doesn't really matter that much?

Thank you, drive thru

 

[waynehartwig]

Doing how you said does seem way easier, but it will give a WAY different setting than how Greg suggested. He is setting his tow-in and the rim edge, you're at the tire edge, depending on the size of your sidewall that's a big differance; for my 37s, it like 11". So a 1/4 inch at one point vs. 1/4 inch 11" farther out is going to make the first much less than 1/4 inch. So I guess I'm saying should tow-in be set at rim edge, or tire edge; or am I ready WAY too much into this and it doesn't really matter that much?

Thank you, drive thru

Since your using the same reference point on both, it doesn't matter. The best way to do it is spin the tire and draw a chalk line on around the tire. Then you are assured that you are the center for both. It doesn't even have to be the center, but you must use the same point front and rear of the tire on both sides.

It's all 6'es.... If you want it done RIGHT, spend the $50 and take it to an alignment shop. Mine and Greg's way will get it so close, there won't be a need for the alignment shop.

 

[jeeponthebrain]

Thanks for all the input on this problem. I have spent some time in the garage and this is what I came up with:
The good news: My bearings are repacked and tight, my tie rod ends are new, my drag link ends are new, my AGR ram has no leaks and has been bled with synthetic power steering fluid, and my hi steer arms are tight.
The bad news: My upper ball joints are worn out and have a little bit of play and my drivers side rim is bent, and after checking the toe, it was way to far toe-in. I have corrected the toe as best I can and did not have dw on the test drive around the block. I will put in new ball joints next week, as for the bent rim...does any one know of a good place to straighten a steel wheel?

 

[waynehartwig]

Thanks for all the input on this problem. I have spent some time in the garage and this is what I came up with:
The good news: My bearings are repacked and tight, my tie rod ends are new, my drag link ends are new, my AGR ram has no leaks and has been bled with synthetic power steering fluid, and my hi steer arms are tight.
The bad news: My upper ball joints are worn out and have a little bit of play and my drivers side rim is bent, and after checking the toe, it was way to far toe-in. I have corrected the toe as best I can and did not have dw on the test drive around the block. I will put in new ball joints next week, as for the bent rim...does any one know of a good place to straighten a steel wheel?

Good to hear it's corrected!

Just get out your BFH and straighten it yourself! If you look at the wheel, you can see the point where it was bent, start hitting it there and move side to side. If you bend it slowly, you can do a controlled bend and make it as good as new again.

 

[jeepers]

Here Is The Most Best Way To Fix It It Happind To Me On My Tj Get Rid Of The Peace Of Sh@t Swampers They Are Junk I Will Never Buy Them Again I Changed Wheel Bearings Steering Stableizer And Track Bar That Helped But Did Not Fix The Problem Then I Got Rid Of Them Swampers And That Fixed It All Drives Like A Dream Now Talk To Wayne A Tera He Will Tell You The Same Thing