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Hey guys, i have no life and decided to try and help some of the noobs out. Hopefully we can sticky this or put it in the NAGCA tech section. Enjoy and feel free to comment:

Death Wobble – a violent shaking at a certain speed or after hitting a bump which vibrates the entire front end viciously. Almost feels like the front end of the Jeep is going to fall off. The only way to stop the Death Wobble (from now on will be referred to as DW) is to slow down to a lower speed. Should not be confused with warped rotors causing a slight vibration in the brake pedal and steering wheel. DW is VERY apparent, and you will know you have it when it happens. It is important to slow down carefully when you have DW, pull to the shoulder carefully. DO NOT SLAM ON THE BRAKES!!

DW can be due to a number of things, lift height is not one of those. Here are a list of causes of DW:

1) Worn out tie-rod or draglink ends
2) Worn out steering stabilizer
3) Warped front rotors
4) Worn out lower control arm or trackbar bushings
5) Loose suspension bolts/components (LCA bolts, trackbar bolts, trackbar bracket)
6) Wheels out of balanced
7) Tire tread uneven
8) Alignment out of whack
9) Improper driveline angles due to improper caster

These aren’t all the causes of DW, and there may be others, but these are the major contributors to DW itself. Important: Lift height does not cause DW, but improper parts or installation can cause DW to happen.

So here are some solutions, ranging from easiest/cheapest to hardest/most expensive:

1) Get an alignment, balance tires, check pressure in tires. Make sure toe (the difference of distance between the front two tires and the rear two tires) is at least 1/8” in, no more. Castor should be set close to stock, remember, most alignment shops don’t even bother to add shims to lower control arms since it takes a lot of time and effort. Make sure you ask them to do a full and complete alignment to specs.

2) Replace stock steering stabilizer with an Old Man Emu steering stabilizer from [email protected]

3) Check if rotors are warped, replace if necessary

4) Make sure all suspension components (LCA’s, trackbar, trackbar
bracket, shocks, swaybar) are all tightened to spec. Sometimes components get loose or out of whack after a couple hundred miles or a wheeling trip. The bolts that need to be checked most are the lower control arm bolts, the trackbar bolts, the jam nuts on the adjustable components, etc)

5) Check/Replace worn tie-rod/draglink/balljoints. Park next to a curb with the tires along the curb, turn the steering wheel towards the curb and have a friend watch and see if any steering parts have slop or play.

6) Replace stock suspension components with after-market products (adjustable lower and upper control arms [JKS, Rubicon Express, Teraflex, etc] and adjustable trackbar [JKS, ORGS, etc])

7) Dial in pinion angles by adjusting the lengths of the upper control arms

8) Get a new trackbar bracket from www.Kevinsoffroad.com

9) Check steering box for damage or stress, replace if necessary

10) Buy new tires/rims

11) GO LONGARMS!!! 90% it fixes DW. www.claytonoffroad.com

Death Wobble is not the easiest thing to get rid of, nor is it the easiest thing to find and cure. It can be an expensive venture, and is not the same for every Grand Cherokee. I personally spent fifty dollars on an alignment and it cured everything for me when I put on a Budget Boost. But when I went to 6”, I didn’t have a single issue with DW. Other people have taken off lifts to try and get rid of DW to no avail, so it is not lift height that matters. It is important to be persistent with DW, but remember, it’s not worth spending too much money on unless you definitely want a lift and know what you are doing.

If you do have a case of DW, it is important to check your steering components and suspension components. The violent shaking can sometimes ruin tie-rod ends, bushings, and loosen bolts.

Please contact me if this write-up contains any mistakes or you disagree with anything or if you just want to add or comment. This write-up is not a sure-fire way to cure DW, but it is a HUGE step towards finding the problem and fixing it. I would say around 95% of the time, the list above cures DW.

Patrick Chung
[email protected]
AIM: alloy171
 

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that is a great write up man.

i would like to add that the steering stablizer is not a cause of DW even if it is worn out. a good, strong ss will help hide DW or make it tolerable. it is there to be an aid.

also, going to long arms seems to fix DW b/c you replace so much stuff.

i would say 9 out of 10 times, DW is due to something loose, worn, or out of wack.

just my experience.
 

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dracer69 said:
also, going to long arms seems to fix DW b/c you replace so much stuff.
Actually, there are MANY reasons why LA systems fixes DW. Heavier duty control arms, better control arm angularity, stiffer track bars, and new componentry, just like you mentioned. DW is a multi-faceted problem. No ONE THING that we've found ever seems to fix most rigs except for the Track Bar Conversion we make. Other than that, you just have to find the offending several pieces that have worn enough to no longer be within tolerance.

Kevin
 

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This is a very good write-up. It covers all the bases that everyone else has covered in the various forums and websights.

HOWEVER, there is one key task that is not mentioned.

INSPECT EVERYTHING FIRST BEFORE ANY REPLACEMENT PARTS ARE USED.

Don't just willy-nilly start slappin on new parts cuz someone says to. Start at the top of the list and work your way down inspecting everything. If you are unsure then ask questions.

Also, if you have to replace parts make sure to re-torque everything after the install. Go over EVERYTHING and make sure it is properly tightened.

You say yeah, I installed it properly and torqued it properly. Still double check things. You have no idea how many times the professionals have gotten ahead of themselves and missed something.

Jeep does not have to mean Just Empty Every Pocket.
 

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Yea I just picked up my second case of DW... I got it driving home after finishing my 1 ton steering. I'll be sure to add some pics and what the fix was after I get it solved.
 

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Yeah, great job! I'd like to add "tread separation". While this seems redundant to "out of balance", "uneven tread wear", & etc., to the noobs the other descriptions may not compute. I got real bad DW after adding a 2" spacer lift. I added adjustable lower control arms to no avail. Took my toy to a tire shop for balancing and found a separated tread on the left front. Four new Goodyears later, smooth smooth! :cool:
 

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My DW fix: Jacked up the ZJ, removed wheels to check #s for BFG recall, put wheels back on and finger tightened slowly all the lug nuts two times around. Then wrench tightened a little at a time going round and round until ~100ftlbs.

I had the tires balanced twice, the last time by someone trustworthy while I watched; the tire jockies at Sears suck, won't do that again no matter what kind of discount I can get. 2" BB, 235x75x15, nothing major as far mods go.
 

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Of the 3 separate times that I had DW, TWO of them were directly resolved by adjusting the caster. The third was because a hastily fabbed (read: sorry-ass) steering damper mount broke. This has been through several progressions and changes with the lift. When I put XJ drop brackets on the front, going back to stock arms, there were no issues, and my ride smoothed out alot.
 

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Bone stock 95 ZJ with UpCountry

On my Mom's 95, they replaced:

1: New BFG AT KO's
2: Replacement tie rod and draglink-stock replacement
3: Replacement track bar-stock replacement
4: New lower control arms-stock replacement
5: New shocks
6: New swaybar bushings

These were done 1 item at a time and alignment was done with the new tires and steering linkage.

It still had DW, no big deal if you or I were driving it, but this is my Mom's.

Next on the list was a replacement motor mount, just because it was worn, I of course let them know that it would not have any effect on the DW.

I was wrong, new motor mount and it is fixed. Same road used for testing before, now it drives over it without a problem.

Maybe the weight of the engine bouncing started the front end oscillating....
 

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I think it would be great for people to describe what steps they took to solve their Death Wobble, and then what actually solved the Death wooble. Thanks for any responses. Ive done the easy stuff now I'm on to bushings.
 

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Problem: The bushings in my KOR trackbar conversion kept going out and causing major DW .... I replaced them like 4 times in 10 months. Solution... RE extreme duty bracket and trackbar
 

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I just replaced my track bar bushing, it didn't cure my death wobble. Now I'm onto replacing the control arm bushings. Errrr this is getting annoying with only a BB.
 

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When was the last time you got your tires balanced and the alighnment done? That and how old are your tires? The first time I had DW, it was because my front tires had very little tread (if that makes sence) and were completelly out of alignment. 31x10.5s and an alighnment later, no DW.

Another thing you might want to consider after you replace the control arm bushings is going with an aftermarket trackbar setup like Kevin's trackbar conversion or the Rubicon Express extreme duty trackbar setup. Both kids lower the trackbar mounting point by a little bit (which will help quite a bit).
 

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Slip Yoke Eliminator?

If I'm experiencing mild DW at highway speeds with a BB could a SYE solve the problem? Would a driveshaft overextended cause a vibration similar to DW?
 

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Re: Slip Yoke Eliminator?

gtagr96 said:
If I'm experiencing mild DW at highway speeds with a BB could a SYE solve the problem? Would a driveshaft overextended cause a vibration similar to DW?
No. I don't think you're experiencing deathwobble. DW will make you shit out your gall bladder the first time you experience it. DW doesn't happen at highway speeds either, it tends to linger about 10mph+/- the 45mph range. It sounds like you have a slight steering shimmy, which is more or less normal and may be related to bumpsteer from the stock inverted y steering and running a little lift. In combination with this, you likely have at least a little driveline vibration that could be solved by running a CV driveshaft and an SYE.

If you do start to experience actual DW, I would recommend checking your alignment, all bushings, and trackbar bracket tightness. If that doesn't help, I would then throw on a more beefy aftermarket steering stabilizer to mask the problem until you can find out its actual source and fix it for good.

Cam
 
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