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death wobble help


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I'm sorry i couldnt find a link with the correct answere, but what is the main cause of death wobble just started happing ing at about 45 mph, as i was goin around a curve then after i staighted out as i get closer to 45 it starts getting bad. also i want to beef up the whole front end , but keep the D30 axle is there a post on here about converting parts for a heaveyer duty stering and tie rod setup?>

 

thanks eric

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Death wobble is almost always a result of many smaller contributing factors. Tire balance, alignment, tie rod/ drag link ends, sloppy unit bearings, control arm bushings, sloppy steering box, track bar, (Either end). The best way to chase it down is to have someone sit in the cab, and with the engine off, have them jerk the wheel back and forth, like 1/8 of a turn, while you are under there looking for something wiggling. If it's all tight, all you'll see moving is the pitman arm turning slightly, and the wheels wiggling. if there is any wiggling between two components, there is at least one culprit! (For example, if there is wiggling between the trackbar and the trackbar mount, replace trackbar. if you see wiggling between the draglink and the pitman arm, time for new rod ends, etc.) All those parts should move in unison with the steering wheel. If they are moving independent of each other, there is at least one of your problems! Have fun!

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Note: don't confuse the pitman arm turning, with slop in the box, which will result in the pitman shaft, (AKA selector shaft),wiggling side to side, instead of turning.

 

This is all why you WON'T Find one cure all answer on here for death wobble!

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I've had death wobble on two Mjs and they were both the same thing. The steering box and the track bar, after I replaced them the steering was perfect again. So after you check all the items philbert listed and IF you can't find anything moving then I would replace the steering box.

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I've had death wobble on two Mjs and they were both the same thing. The steering box and the track bar, after I replaced them the steering was perfect again. So after you check all the items philbert listed and IF you can't find anything moving then I would replace the steering box.
:agree: Yup! After replacing every one of those things, it turned out to be the last two. Control arm bushings, and steering box!
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Mine went away after I did a front end alignment, and brought the caster closer to spec. I never had it until I swapped in the 4x4 front axle while doing a conversion. I also added the 4x4 springs and an extra isolator, so I knew the caster was off ( too little). I didnt do the caster adjustment at first because I still needed to add longer rear shackles. So after I did the shackles, I did the alignment again, and added shims to the caster adjustment. I started out at about 4 degrees, and ended up about maxed out in shims at just over 6 degrees. Factory spec is 7.5 degrees. But after the adjustment Ive yet to have another problem. Like was said, it is usually a combination of issues that come to an end result of DW. If you have too little caster, a slightly off balance tire and minor wear in other places, will cause it to start. Some people have noticed as they change one part at a time, that the speed at which the DW starts changes. You just have to keep picking at it, do as many things as you can to make sure everything is good, and youll eventually get it.

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There is no single thing to point at for death wobble. Personally, I always look first at tire balance, because death wobble does not and cannot occur unless at least one tire starts ... well, wobbling. And steering boxes, track bars, drag links, tie rods, and shock absorbers cannot cause a tire to start wobbling.

 

But ... death wobble is different from "wheel shimmy" in that when one front tire starts to bounce around, it gets transferred to the opposite side and they then engage in a dance of harmonic reinforcement -- each feeding the other until the vehicle tries to jump off the road.

 

I've had true death wobble twice, in two different vehicles. One was my '88 MJ. Tires were out of balance. I had driven it for two or three years, with no issues. I swapped on a different set of tires, and BAM! Took 'em off, and never had another problem.

 

The other instance was in a 6-month old, box stock 1999 Grand Cherokee and it happened on a smooth state highway after I had driven about 150 miles. I touched the brakes to stay close to the speed limit on a long down grade, and HOLY WHEEL HOP, BATMAN! Nothing was loose, and the tires had no shimmy. But ... the front rotors on the '99 Grands liked to warp, and mine were warped. That's all it took. Also, I had the off-road ("Up Country") suspension, and I subsequently read that Jeep had to change the spring rates and the durometer on some rubber bushings with the "export" suspension because of death wobble. So I suspect that the U.S. Up Country suspension probably was about the same as the export suspension.

 

All those other things people have mentioned become possible culprits if a tire starts wobbling, because they allow for more wobble to be transferred across to the opposite wheel. But start by checking the tires for balance.

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:agree: with Eagle, but for financial reasons I would start with the alignment, then move from there.

 

As a person who has (at least for rignt now) solved the DW problems in my son's 89, the saga went like this:

 

Alignment

Steering box / pitman arm

Track bar

Lock washers on track bar mount bolts (they kept working loose :dunno: )

UCA and LCA with bushings

Upper and lower ball joints

Steering arm and tie rod ends

Alignment

 

Now, the steering is tighter them a bull's butt at fly time, and no more DW...no matter how hard we try to make it happen.

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:agree: with Eagle, but for financial reasons I would start with the alignment, then move from there.

 

As a person who has (at least for rignt now) solved the DW problems in my son's 89, the saga went like this:

 

Alignment

Steering box / pitman arm

Track bar

Lock washers on track bar mount bolts (they kept working loose :dunno: )

UCA and LCA with bushings

Upper and lower ball joints

Steering arm and tie rod ends

Alignment

 

Now, the steering is tighter them a bull's butt at fly time, and no more DW...no matter how hard we try to make it happen.

:agree: It sucks replacing so much and seeming to get nowhere with it, but once you do all this stuff, and Get it right, it IS like a brand new truck!
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x2 to youall

 

i gave the last thing i did, but my history:

 

replaced track bar with adjustable one. had bad bushing

 

replaced steering box. worn shaft bushing

 

replaced pitman arm, wobbled on shaft

 

replaced end bushing on steering shaft, bad bushing

 

replaced bushing on passenger side of tie rod, bad bushing

 

i have six 33in bfg's that i interchange. one of them that i put on the front passenger side wouldn't completely balance, and i found out the hard way that it would start the death wobble. kept looking.

 

lower lca arms are RE ones. they were put on backwards. mounted them correctly. also, one johnnie joint was bad. replaced it. didn't like the look of the solid bushings, and at this time i was spooked, so replaced them.

 

replaced uca arms frame side bushings, same reason as above. at this time of replacing the control arms i noticed the holes were rounded on the frame mounting points and the front attaching point of the uca to the axle. i made a bushing for each side of the uca and pressed them in. i then bought bolts that fit better than the old ones and installed them.

 

lastly, my lca were at 45 degree angles instead of flat. so i had made long arms to correct this problem. finally i can say no more death wobble.

 

the time line is spread over a two years. different things would work for a while, then back DW would come.

 

a previous owner had some one put in a d44 from a chevy truck. the workmanship was klqjtjqo2t2!!!

 

i wrote all this to say ,you might be fortunate. or you might have my luck. but it can be found and fixed! dave comanche.gif

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Mine was quite "invigorating", and I found nothing loose. Turns out the truck had old tires that

weren't able to be well balanced. I road force balanced those tires and the problem was 90%

solved. New tires with road force balance and the truck is now smooth as grandma's Oldsmobile

(comparatively speaking). I can now enjoy tucking into a corner instead of wondering which

ditch (or pole) I'm going to wind up nosed into. Old tires can have plenty of tread, but the

tire man convinced me he can tell the tire age by codes on the sidewall. Said there was probably

internal separation.

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