Death wobble - revisited

[Dre]

And once again I've got my beast running... complete this time. Alignment done, Flawmaster in... ready for some action. And I might take it somewhere for a day of wheeling but first I'd like to address a problem that I've had with my truck ever since I lifted it. DEATH WOBBLE - it is called. What causes it? Why my truck? How to counteract? I know we were speculating for a while but this time I need to find a fix.

I know, I won't be driving my truck on the highway a lot... but still, I need to get to the trail somehow and that will require driving at speeds higher than 60 mph once in a while. 60 mph, that's where death wobble springs into action and makes driving any faster just plain dangerous. Truck starts behaving like a boat on water, wobbling from side to side. How can I get rid of it? Can it be fixed with a steering stabilizer? Can it be fixed by installing a sway bar back? now with the sway bar I would need some drop brackets and quick disconects...


did anyone tackle this problem with some success?

 

[jimbo74]

hate t osay it, but death wobble is a problem that there are tons of possible fixes for....

 

[JTX]

I wouldnt say the sway bar. I had mine off and it didnt really wobble to bad. Just mainly swayed. Did you ever pull your rear drive shaft apart? I know if it comes apart and you dont line the yokes up together that will cause a nasty wobble. Also mine wobbled really bad when there was try mud in the back of the rim. You might wanna check that out. Just my 2 cents......

 

[unclemeat]

I have had to replace radius arm bushings and added a james duff steering stabilizer. It rides good at highway speeds. If the tire pressures get low or much different the death wabble will come back.

 

[glfredrick]

If you are running a later model like your signature says - you might want to check out the front wheel bearings... They are self-contained in a hub and prone to failure - especially with larger tires. They would give you the wobble you are talking about.

 

[Dre]

well, I've got the wobble on my 94 Sport. At highway speeds (over 60 mph) truck starts rocking from side to side - just like a boat on water. That's when I have to reduce speed to get it back to normal. I also get real bad vibrations at like 65 mph. I believe that rear drive shaft was taken apart to align the rear end after axle conversion. I did the conversion but then had a shop align the shaft and weld spring perches. The guy at the shop told me that it would be a wise idea to replace shaft with a CV joint type of shaft (custom made) to get rid of vibrations. I don't think that there any mud is stuck on rims... truck was not off-road yet (maybe that's what the truck needs!!! take it off-road so the parts recently installed would settle and align properly).

As for radius arms? I've got extended Skyjacker radius arms with brand new bushings.

I'm thinking that perhaps the main reason for the wobble is that the suspension is too soft. Perhaps Skyjacker shocks are not really up to the task? install double shock towers?

 

[glfredrick]

With a few more details, it may be what you think...

What you are describing is not the typical "death wobble" which is usually a violent shaking of the steering wheel at speed. Talk about scary - I have seen it a few times on lifted Cherokees when they don't get the adjustable radius arms and the caster is out of wack...

You may be too soft. There are easy cures for that. I'd start with a couple of clamps on the rear leaf springs. Tie the leaves together, just use something temporary and test it - like a c-clamp or something.

In the front, try filling your springs wit tennis balls for a test. They will stop the downward movement and let you start to see if you are just too soft...

Are you running sway bars? I would recommend them on the street, but make disconnects for off-road.

 

[Dre]

clamps for the leaf springs would be nice. I was even ready to install an extra leaf to stiffen the back but the truck would look real funny with back sticking-up - it's level now and with 6" of lift in the front with 1.5" spacers and SOA conversion in the back I'm pretty high as it is.

I've got no sway bars at all. Stupid me I got rid of them completely. No way I can install one in the back cause I'm using sway bar mounts as new attachment points for the shocks.

Front? I think that I have even removed sway bar mounts off the axle when lifting my truck.

I might have a problem with weight distribution now... 1.5" spacers were installed to level the truck after bumper/winch installation. Bumper/winch weights at least 300 lbs easy. Front might be too heavy - springs too soft - shock not hard enough - - - - - I might try adjustable shocks for a change to see what happens when I set them to firm position.

Steering stabilizer and sway bar should fix the problem.

If not, I might consider dropping the truck back a couple of inches and putting axle back where it was. Safer set-up? maybe. I'm just wondering about all the guys that put a combination of lifts to get 10 and more inches of lift... how's driving at highway speeds?

 

[glfredrick]

Just the front sway bar ought to do it...

Try one from the 1st gen. They are pretty generic. Just bolt it up to the frame somewhere, and make a couple links somewhere to the axle or A arms in your case. Make the links removeable and as long as needed to get from the frame to the mounting points.

The soft shocks might contribute, and if you can afford them, the Ranch adjustable ones are pretty good- and they get stiff... I can set mine up like a go cart - or I can have it bounce and hit the frame on the ground with a twist of the dial.

The rear sway bar isn't gonnna do much anyway, so I would ignore it...

 

[Dre]

FYI - I'm talking about a first generation... that's my toy. The 98 is my wife's baby - she won't let me touch it.

 

[JTX]

Adjustable shocks do alot. I have them and if your driving you can tell if one is one notch softer. You may wanna try to get some R9000's on it.

 

[Chew_12]

Ya let me know how it goes. I will be getting a SL soon and hopefully I wont have this problem because I need to drive between two cities a lot!

 

[SnowExploder]

Ugh.. I had death wobble... any time I went above 40 mph it would start, it was the scariest thing ever...
You know what completly fixed it? New ball joints... I had the inner's and outer's replaced and have not wobbled since. Might want to check that out if you get a chance and haven't already. Mine went bad about 2 weeks after I lifted it...(same issue with my friend Brandi's full size, she wobbled, replaced the ball joints and was good to go)

I've got no sway bars at all. Stupid me I got rid of them completely. No way I can install one in the back cause I'm using sway bar mounts as new attachment points for the shocks.

Hmm.. I have no sway bars and I have no sway, none... a friend of mine with the exact same set up but with sway bars, has more cab roll then I do... In my case they made no difference.

 

[glfredrick]

OK, I was thinking that you had a 2nd gen by your sig... On a 1st gen, I would check to see that the wheel bearings are tightened and that the nut hasn't backed off. In your case, it is still likely to be the springs - though I am running very soft springs on mine and no sway bars at all - and have no issues to past 100. It just leans a bit in the corners if I'm not careful to jack the weight around some.

Get the RS 9000's and while you are at it - put in the F 250 shock mounts up front and get some longer shocks. You will have to spend some time in the shock book to find the right one. I am running Jeep XJ 2" lift shocks on the front of mine - they are about double the length of the factory shocks... They give great flex off road - and are plenty stiff when cranked up on the road.

I'd also check toe in again. Maks sure that your alignment is done right. That will also cause the pulling that you describe.

What about tire PSI? Also, how wide are the rims and what size tires?

Best of luck on your hunt for the problem...

 

[Doug]

I used to get really bad death wobble on my truck when my front shocks started going. I'd hit a bump on the highway and I'd not only start rocking I'd start to loose control. Definantly try some adjustable shocks up front and the front sway bar with some quick disconnects.

 

[unclemeat]

Increasing tire presure increases spring rate, stiffens the ride.

 

[jrgaylor]

I use to scare the hell out of people on the freeway untill I went to 40 psi in the tires, if i was doing better than 60 and made too fast of a lane change I would start to wobble and they would give me lots of room, But the wife did not like that.

 

[brianb]

I had what i refered to as the "death shake" one time in my 95, im almost positive it was caused by a wheel balancing weight that came off at 70 miles an hour. Hey its an easy fix and worth a look.

 

[Dre]

thanks for all the replies but I think that my problem is in being too soft up front. Alignment was just done, everything is brand new (complete lift). Entire front end is brand new for that matter. Ball joints were replaced also. Bearings are still fine and tight. I think that when I put some adjustable shocks in, install a sterring stabilizer and a sway bar with quick disconects, I'll be fine.

Rear is another issue all together. Springs are just regular 4 door spring packs. I wish I had enough room back there to throw an AAL for more stiffness.

Today on my way to work truck rode fine with a few exceptions... I even got it up to 80 mph and was still able to control it. Maybe I just need to brake it in?

One more thing as someone asked me about it... I'm running 33X12.5" tires on 15X10 rims.

 

[DeRocha]

Today on my way to work truck rode fine with a few exceptions... I even got it up to 80 mph and was still able to control it. Maybe I just need to brake it in?

There is a fine line between breaking it in, and getting used to it. The more you drive it the more you'll get used to it riding the way it does.