The DEATH WOBBLE database
JK Junkie
Joined: Sep 2007
Posts: 2,164
Likes: 0
From: Catonsville, MD
Well Months ago I took my 35's off and put my stockers on while I changed out tires. Got DW 4 times within 10 miles. I knew the tires werent balanced and figured that was the problem until last week. I put the balanced stockers on so I could get an alignment, and voila, guess who made a reappearance. Ole DW. Now let me say that I know it is DW for sure, as it feels as if the JK is tearing apart from the inside. It is so Violent that I was afraid it would crack the hardtop. I had a friend behind me and he said it looked as if all 4 wheels were gonna fall off. I have just recently took a trip in the Jk that was 600 miles with the 35's on with no Dw issue what so ever. I have never had DW with my 35's on, but my JK sure doesnt like the stockers. Feels like it is trying to shake them off. Track bar is torqued to 140 lbs. Figure this out, I am stumped. It isnt an issue unless I put stockers on. I am thinking of replacing my ball joints with some of those HD ones everyone is talking about.
Moral of the story......Keep your Jeep in big shoes....he's much happier
JK Enthusiast
Joined: Jul 2008
Posts: 294
Likes: 0
From: Seaford DE
Think about it for a minute.....lets say you wear a size 12 shoe and you stick your feet in a size 8.....you are gonna walk like crap....now put your 12's back on and your feet are happy and you walk fine.
Moral of the story......Keep your Jeep in big shoes....he's much happier
Moral of the story......Keep your Jeep in big shoes....he's much happier
Death Wobble and Bumpsteer are both caused by poor steering geometry. DW is usually induced by bumpsteer.
You can buy a beefy adjustable trackbar and bolt it on, but if you don't correct the angles, it won't fix the problem.
Fancy bends and shapes don't mean anything. You have to pay close attention to the mounting points.
Put a strip of thin painters tape between the axle bolt and the frame bolt on the trackbar.
Do the same between the pitman arm and the knuckle on the draglink. These angles should match, and the lines should be parallel. If they are not, your geometry is off. There are plenty of brackets out there, but sometimes you have to find good help.
Without a drop pitman arm, AND with my over-the-knuckle draglink, my trackbar mounting point at the axle needed to be 4" over axle center. I like to avoid DPA's if possible. I made my own bracket out of 1/4 plate. RK also makes a nice bracket that you can bolt/weld on.
But don't just bolt crap on without checking your angles and doing some math.
I drive 80mph on the highway with 40's and no steering stabilizer. I hit potholes and dips with no bumpsteer or wobble. IT'S ALL ABOUT GEOMETRY!!
You can buy a beefy adjustable trackbar and bolt it on, but if you don't correct the angles, it won't fix the problem.
Fancy bends and shapes don't mean anything. You have to pay close attention to the mounting points.
Put a strip of thin painters tape between the axle bolt and the frame bolt on the trackbar.
Do the same between the pitman arm and the knuckle on the draglink. These angles should match, and the lines should be parallel. If they are not, your geometry is off. There are plenty of brackets out there, but sometimes you have to find good help.
Without a drop pitman arm, AND with my over-the-knuckle draglink, my trackbar mounting point at the axle needed to be 4" over axle center. I like to avoid DPA's if possible. I made my own bracket out of 1/4 plate. RK also makes a nice bracket that you can bolt/weld on.
But don't just bolt crap on without checking your angles and doing some math.
I drive 80mph on the highway with 40's and no steering stabilizer. I hit potholes and dips with no bumpsteer or wobble. IT'S ALL ABOUT GEOMETRY!!
Thanks
JK Enthusiast
Joined: Apr 2007
Posts: 283
Likes: 0
From: York Pa
1. Year and Model 2007 unlimited x
2. Current Mileage46k
3. Approx mileage when DW started45k
4. Suspension (OEM, etc. Make sure you list all components like AM trac bar, CAs)bds 3" lift jks adj trakbar, jks adj lower control arms
4. Wheel/Tires/spacers315/75/16 5" backspacing
5. What measures you have taken to resolve DWdouble ck track bar. ck tire pressure, teraflex steering stabilizer.
6. What was the"fix" or are you still dealing with it I think the fix was making sure my tires were inflated the same
__________________
2. Current Mileage46k
3. Approx mileage when DW started45k
4. Suspension (OEM, etc. Make sure you list all components like AM trac bar, CAs)bds 3" lift jks adj trakbar, jks adj lower control arms
4. Wheel/Tires/spacers315/75/16 5" backspacing
5. What measures you have taken to resolve DWdouble ck track bar. ck tire pressure, teraflex steering stabilizer.
6. What was the"fix" or are you still dealing with it I think the fix was making sure my tires were inflated the same
__________________
2007 JK Unlimited 6 Speed 4.10 Gears
3 Inch BDS Lift
35x12.5x16 Yokohama Geolander AT/S
16x8 Cragar Soft 8 Black Steel Wheels
Custom front Winch Bumper from RoundStar OffRoad
Mopar Offroad Rear Bumper
Oilpan/Tranny skid Plate by Skid Row
JKS Quicker Disconnects
Skyjacker Brake line extenders
Skyjacker Adj Rear track bar
High Clearance Adj Front Lower Control Arms by RocKrawler
RocKrawler Front Lower Control Arm Mounting Bracket/Skid Plates
Warrior Products Rear Safari Doors
Plenty of ROCKRASH
JK Enthusiast
Joined: Feb 2007
Posts: 196
Likes: 0
From: North Carolina
So some of these guys that say they have a stock Jeep and get DW (it happens, I have been in one) have bad geometry? Are (or were I guess) the specs at the Jeep plant so loose that it can mess up the geometry of one Jeep and not another? Or are you saying ALL of us have bad geometry from the factory, and we need to buy a new Jeep, and then spend $$ and time "fixing" this geometry? I personally trust someone with a degree in engeneering than my own attempt to correct suspension geometry with a degree in chemistry. lol
JK Junkie
Joined: May 2007
Posts: 2,288
Likes: 0
From: Treasure Coast, Florida
1. Year and Model: 2007 unlimited X
2. Current Mileage: 25,000
3. Approx mileage when DW started: 20,000
4. Suspension (OEM, etc. Make sure you list all components like AM trac bar, CAs): 3" Full Traction w/trackbar brackets, 1" Teraflex spacers
4. Wheel/Tires/spacers: 15x8"/35x12.50/ 1/4"
5. What measures you have taken to resolve DW: Tighted every bolt, installed adjustable control arms, installed dual steering stabilizers, played around with alignment
6. What was the"fix" or are you still dealing with it: The fix (WHICH TOOK FOREVER TO FIND) was re-centering the 1/4" wheel spacer which was a fraction out of alignment and caused a huge amount of wobble. . . But hey, it got me some cool new parts!!!
2. Current Mileage: 25,000
3. Approx mileage when DW started: 20,000
4. Suspension (OEM, etc. Make sure you list all components like AM trac bar, CAs): 3" Full Traction w/trackbar brackets, 1" Teraflex spacers
4. Wheel/Tires/spacers: 15x8"/35x12.50/ 1/4"
5. What measures you have taken to resolve DW: Tighted every bolt, installed adjustable control arms, installed dual steering stabilizers, played around with alignment
6. What was the"fix" or are you still dealing with it: The fix (WHICH TOOK FOREVER TO FIND) was re-centering the 1/4" wheel spacer which was a fraction out of alignment and caused a huge amount of wobble. . . But hey, it got me some cool new parts!!!
JK Enthusiast
Joined: Aug 2008
Posts: 180
Likes: 0
From: Roaming around Utah
I experienced my first DW this weekend after running the Rubicon.
Repeatedly smashed my steering damper and bent the tie rod (among other things).
The tube was so hammered that the steering was binding so I took the stabilizer off and drove it home (over 500 miles). The next morning I couldn't even get out of the neighborhood without it doing the epileptic mambo.
The new tie rod and stabilizer will be on tonight and everything tightened up and aligned- so here's hoping!
Repeatedly smashed my steering damper and bent the tie rod (among other things).
The tube was so hammered that the steering was binding so I took the stabilizer off and drove it home (over 500 miles). The next morning I couldn't even get out of the neighborhood without it doing the epileptic mambo.
The new tie rod and stabilizer will be on tonight and everything tightened up and aligned- so here's hoping!
JK-Forum Founder
Joined: Jul 2006
Posts: 36,534
Likes: 16
From: Laguna Niguel, CA
To assure a comfortable ride and steering performance the engineers have tightened up the neg. scrub radius to about 14mm negative (The TJ was much more) This tight design box will NOT allow much "variations" from the initial steering design geometry. Tire balancing, tire patch on the ground (tire pressure and tire flank quality) wheel offset, dynamic TOE-in and caster and last but not least what was referred to by 4LO (draglink and track bar parallelism) are important variables which will be affected with lifts, wheel and tire changes, neglected tire maintenance..etc..
As you can see (granted with some imagination) that a bump can rotate the knuckle violently inwards and this become the start of the oscillation.. (Here is also an argument to be made about the steering dampener quality.
A initial bump is enough to set the DW oscillation in motion..
I have come to the conclussion that the design as is, is very "DW friendly" (cannot come up with a better wording..)
I have come to the conclussion that the design as is, is very "DW friendly" (cannot come up with a better wording..)
Stock units with DW are just a "proof" about the poor design reliability and robustness..Manufacturing Quality variations (Also called Quality Noise) should be included into the design reliability parameters..
Further, the poor Quality Control systems at Chrysler are not helping as I am sure that a stock jeep with DW will have parts out of specification..
Further, the poor Quality Control systems at Chrysler are not helping as I am sure that a stock jeep with DW will have parts out of specification..
Last edited by wayoflife; Jul 21, 2009 at 07:21 AM.
Thread Starter
JK Super Freak
Joined: Feb 2009
Posts: 1,942
Likes: 1
From: Tampa, Florida
I think that loose or broken components are the CAUSE of death wobble, not suspension geometry although that may contribute to the amplification of DW affects. Just sayin. Pretty sure there was not field of study in Jeep suspension in college
To say a stock unit is proof of poor engineering is a a joke right? That statement in itself just tries to remove the responsibility of the owner/operator. It is called preventative maintenance... you even have to maintain a ferrari.... and their engineering is top notch.... just saying. You can't pawn of personal responsibility on every manufacturer.... is it Zest's fault that their soap disappears with excessive use?
To say a stock unit is proof of poor engineering is a a joke right? That statement in itself just tries to remove the responsibility of the owner/operator. It is called preventative maintenance... you even have to maintain a ferrari.... and their engineering is top notch.... just saying. You can't pawn of personal responsibility on every manufacturer.... is it Zest's fault that their soap disappears with excessive use?
Last edited by greenamphibious; Jul 21, 2009 at 07:34 AM.
JK Enthusiast
Joined: Aug 2008
Posts: 180
Likes: 0
From: Roaming around Utah
Guys! Everybody R E L A X .......
This isn't the Death "Squabble" database thread. Open forums are about sharing questions, ideas and experience. Then we all form our own conclusions and learn from each other. Differences of opinion are a natural by product of such discussions. Let's take a step back and not let it get personal.
Wobble on!
This isn't the Death "Squabble" database thread. Open forums are about sharing questions, ideas and experience. Then we all form our own conclusions and learn from each other. Differences of opinion are a natural by product of such discussions. Let's take a step back and not let it get personal.
Wobble on!