Violent Vibration!

[DMaddox]

All I can say is holly crap! To say violent vibration is an understatement. Here is the scenario.



Driving approximately 70-75mph, on a freeway and turning slightly (i. e. , not going straight) right or left. I'm on an overpass and the joint in the concrete causes the truck to loose balance (that's the best way I can explain it. ) At which point the massive, violent vibration begins. At first I thought the wheel fell off or something and I thought I was going over the side of the overpass for sure. I stepped on the breaks and it got a little worse, but I had to do something to stop. I'm in the fast lane and have to slow down to 30mph until the vibration finally stopped. Needless to say, the drivers behind me weren't real happy. Watching them stare as they drove past I wasn't sure if they were ****** off or just amazed at what they just saw. I'm not a mechanic so I can't tell you if it was the wheels, tires, drive shaft, steering components or whatever. I do know it was VIOLENT. Any thoughts on this? I took the truck to the dealer and they said they put it up on the rack and couldn't find anything and they took a test drive and couldn't duplicate the vibration. I don't like this at all.

 

[rbattelle]

There's a reason it's called "Death Wobble". Uncontrolled resonant vibration system setup in the suspension. Is the truck's suspension stock? Death wobble happens more often in modified (lifted) trucks, but has been known to occassionally strike stock trucks.



-Ryan

 

[REFLOYD]

need info on the truck 2 or 4 wheel drive.



it sounds like a case of the death wobble. caused on the second gens alot by the track bar.

 

[CPittman]

Sounds like a classic case of "Death Wobble" - my guess is the truck has a lift kit, oversized tires (or both), or pulling a trailer with a high tongue load... yes / no?

 

[DMaddox]

Thanks for replies. Death Wabble huh, that sounds just wonderful. A little more info. about the truck. 2006, Turbo Diesel, 2500, 4wd, automatic trans, other than the leveling kit, everything is stock. It's got 9k mi.



Can this Death Wabble be fixed?

 

[Cattletrkr]

... other than the leveling kit,...

And how does one go about leveling a CTD? You might want to look there first.

 

[Nate]

Yes it can be fixed.



First check for loose/worn steering components. Tie rod ends, track bar, etc.



Next check your alignment, also make sure the tires are balanced.



Most of the time Death Wobble is caused by not enough caster, too much toe in or worn/loose steering components (or all 3)

 

[DMaddox]

Not sure cattle, from what i can tell it's some sort of spacer, I think placed on top of the springs, so as to level the front end with the rear of the truck. The dealer did it before I bought it. Do you think that would cause this Death Wobble mentioned above?

 

[Nate]

No, the spacer won't cause death wobble... though the fact that the suspension is lifted 2" in the front does throw off the alignment, so if it wasn't aligned, that could be your issue.

 

[DMaddox]

Just curious, why is it called death wobble?

 

[BStoecker]

Because if it happens at the wrong time, you are dead.



Definitely get your tires balanced and rotated. Also, increase your air pressure in your tires. If I leave my BFG's at the recommended pressure I will get death wobble if I hit a bump on one side or the other at anything over about 40mph. The dealer "could not duplicate" just as expected... If I inflate them to at or just below the recommended towing pressure, I don't have any issues. The ride quality goes down, but my mileage goes up and I don't have to worry about driving into the ditch because of DCX's poor suspension engineering. You would think they would get this stuff redesigned at some point. The same design did the same thing in the Grand Cherokee since the beginning of that platform in '93. It's only been happening for at least 14 model years now.

 

[Alphacowboy]

what I have found (2nd gen) is the following to cause death wobble... .



1. ) Camber is WAY off. With stock control arms and a 2" spacer, the cam bolts should be adjusted to full forward. Basicly adjust them so the lower end of the axle is pushed forward. if the are pulled back or in the stock location, its like wheels on a shopping cart, and they will flop all over.



2. ) Toe-in, check your toe-in. My truck after swaping the steering linkages out, I didnt double check the toe-in, and I had DW after swapping the steering which I hadnt had in a LONG time. Turns out the toe-in was damn near 1-1/4".



3. ) Tires, how are they wearing? mine were cupping on the outer lugs on bothe tires, and most likely from the toe-in being off and the top of the axle being forward. Rotate your tires!





I did all the above after experiancing DW yesterday 3 times! Never had an issue with it before, but have had it 4-5 times in the past week. And what I have mainly attributed it to was the cupping of the tires and toe-in. the camber was never messed with when I swapped the steering out. and it was fine for about a month, until the other day. The only thing that really could have caused it are the cupped tires and toe-in in my mind. ALso, the last time I experianced this DW was over a year ago, and that was with a set of cupped Off-road tires that I was temporarly running. No other changes to the truck but tires and instanly got death wobble.



I did all the above adjustments, test drove it, and MUCH better! I drove over a spot that gave me death wobble twice yesterday, and it sailed over it with out incident!

 

[sag2]

With the spacer on the top of the spring it changes the front end angles. If you lift them too far you need to get longer lower arms to keep the caster in spec. Have the front end checked and get as much caster as possible, five degrees is not too much. Also make sure they hit every bolt on the front end with a TORQUE wrench, and not the one that has an air hose on it!

Get the front end tight and the alignment angles right on, tire pressure and balance good and you should be fine.

 

[CPittman]

IMHO - on a 2006 truck there should be nothing worn enough to cause DW - so unless you've been doing some high-speed off-road jumps with your truck or driving over curbs at speed - the culprit is clear: remove the lift kit and your problems should go away. Unfortunately, you probably will not be able to get the dealer to remove it for you, but I would definitely ask.



Your other solution would be to call Kent Kroeker at KORE to purchase his DW fix.

 

[Alphacowboy]

he doesnt need to remove the spacer... . I bet the Delaer put the spacer in and called it good, if they didnt adjust the control arms, there is your problem. Like said above, crank those cam adjustment bolts so that it pushes the bottom of the axle as far forward as it will go. Then drive it, if it pulls to one side, pull the opposite back slightly, and test it out until its straight.

 

[Alphacowboy]

oh, and nothing against Kore, but come on, he has a leveling kit, and I doubt he is going to be running his truck in a baja race any time soon. THere is no reason to toss that amount of $$$$ at a problem that can be solved with a simple alignment. For a DD street truck, a leveling spacer is more than safe and reliable. I had these on my last truck and not once did I experiance DW with a 2" spacer. I did how ever make sure I rotated my tires every 5k and also made sure the alignment was in spec, or even a little beyond spec on the lower cam bolts. Take a look at the axle once, and you will see why having the axle even slightly tilted forward will cause DW. It puts the axle "c"s facing at a downward angle. this is NOT a good idea.



Lean that axle back and you will be good as golden.

 

[FullSack]

are you running stock tires? It seems that most guys are having problem with DW when running the 315's

 

[Nate]

1. ) Camber is WAY off. With stock control arms and a 2" spacer, the cam bolts should be adjusted to full forward. Basicly adjust them so the lower end of the axle is pushed forward. if the are pulled back or in the stock location, its like wheels on a shopping cart, and they will flop all over.

Caster, not camber.

 

[Alphacowboy]

Caster, not camber.

sorry, my mistake!



so that begs the question, why do they call them Cam adjustment bolts/washers then?

 

[Boondocker]

sorry, my mistake!



so that begs the question, why do they call them Cam adjustment bolts/washers then?

Because it's a cam lobe, just like the lobe on a valve train cam. Cam is not short for camber.



You might also get a heavy duty steering stabilizer. I've dealt with DW on my Jeep ZJ. So far not on the truck, but it's fortified with DSS, 3rd Gen trackbar kit, no lift, tires rotated, alignment checked, yada, yada.



I was surprised he asked why it's called Death Wobble. That's intuitively obvious, like a revelation when it happens to you



Neil