death wobble - JeepForum.com
Search  
Sign Up   Today's Posts
User: Pass: Remember?
Advertise Here
Jeep Home Jeep Forum Jeep Classifieds Jeep Registry JeepSpace Jeep Reviews Jeep Gallery Jeep Clubs Jeep Groups Jeep Videos Jeep Events Jeep Articles
Go Back JeepForum.com > Models > Jeep Wrangler Forums > JK Wrangler Technical Forum > death wobble

Introducing MONSTALINER™ UV Permanent DIY Roll On Bed LineNEW!! HMF 50"-52" light bar mounting brackets!! Year End Clearance Sale! Save 20%

Reply
Unread 04-29-2009, 04:57 PM   #1
cybersniper
Registered User
2007 JK Wrangler 
 
Join Date: Apr 2009
Location: spain
Posts: 6
death wobble

the car runs nice and smooth until the road gets bumpy, then the suspension reacts as it has vibrationg and sometimes I even get a death wobble on my diesel 2.8CRD JK Unlimited. It has a 2,5 TERAFLEX budget boost and the suspension is very stiff on the first few inches it jumps over bumps.

I am tired of changing steering dampers and feel like taking out the BB kit and taking the JK back to Jeep so they can fix it.

The dealer has changed two steering dampers and I installed a aftermarket one too... to no avail. The vibration is still there.

I feel like the whole steering is badly designed as it has too los advance (caster) set at 2 degrees. That seems to me as too low.

What can I do???

Thanks
Thanks
eduardo

cybersniper is offline   Reply With Quote Quick reply to this message
Unread 04-29-2009, 06:45 PM   #2
robsbluerub
Registered User
2007 JK Wrangler 
 
Join Date: Dec 2006
Location: Lynchburg, VA
Posts: 273
First of all PLEASE do not ever call a JEEP a "car"!!! It is a jeep, enough said.

There are many threads on the forum about death wobble, give them a read before you do anything drastic. The steering damper is not the issue - it is a helper but is not required. The number one issue contributing to death wobble is loose components (e.g. track bar). Check to be sure everything under there is tight. Don't go to your dealer as most will continue to replace things that don't need replacing. The second possibility is front end alignment followed by out of balance tires. I rotated my tires last week and with no other changes introduced what acts like a death wobble, really just an annoying vibration, at 52 mph.

So get under there and become one with your Jeep. If everything is tight then go to your trusted tire shop and check the alignment and balance.
robsbluerub is offline   Reply With Quote Quick reply to this message
Unread 04-29-2009, 06:46 PM   #3
robsbluerub
Registered User
2007 JK Wrangler 
 
Join Date: Dec 2006
Location: Lynchburg, VA
Posts: 273
Oh yea - I'm quite jealous that you have a diesel.
robsbluerub is offline   Reply With Quote Quick reply to this message
Unread 04-29-2009, 06:53 PM   #4
$lick
Registered User
1997 TJ Wrangler 
 
Join Date: Jun 2005
Posts: 816
http://myjeeptj.com/2008/11/08/nth-degree-jeep-tj-tech


solves all your problems there.
__________________
1997 Wrangler 2.5L 5spd

Suspension specs:
RE 3.5, 1.25 JKS BL
Old Man Emu shocks
Teraflex adjustable front trac bar
JKS Disco's
Axle specs:
Dana 30- Superior 4.88's
Detriot tru-trac locker
Dana 35- Superior 4.88's
Riding on:
33x12.50 BFG A/T
Black Cragar soft 8's
$lick is offline   Reply With Quote Quick reply to this message
Unread 04-29-2009, 06:56 PM   #5
cybersniper
Registered User
2007 JK Wrangler 
 
Join Date: Apr 2009
Location: spain
Posts: 6
sorry

Quote:
Originally Posted by robsbluerub View Post
First of all PLEASE do not ever call a JEEP a "car"!!! It is a jeep, enough said.

There are many threads on the forum about death wobble, give them a read before you do anything drastic. The steering damper is not the issue - it is a helper but is not required. The number one issue contributing to death wobble is loose components (e.g. track bar). Check to be sure everything under there is tight. Don't go to your dealer as most will continue to replace things that don't need replacing. The second possibility is front end alignment followed by out of balance tires. I rotated my tires last week and with no other changes introduced what acts like a death wobble, really just an annoying vibration, at 52 mph.

So get under there and become one with your Jeep. If everything is tight then go to your trusted tire shop and check the alignment and balance.
Sorry for calling my Jeep a car, Im spanish and sometimes words come out wrong.
I have done all you tell and its still there.

Can somebody help me with the caster adjustment and toe-in for the JK in the US?

Thanks
Eduardo
cybersniper is offline   Reply With Quote Quick reply to this message
Unread 04-29-2009, 07:15 PM   #6
USAntigoon
Retired from Forum
2008 JK Wrangler 
 
Join Date: Jul 2008
Posts: 1,084
I believe you have added weight because of the diesel.. This "sag" has compressed your springs most probable beyond the initial soft ride (more coils windings are in compressed state). A spacer lift is OK providing you maintain the same stock weight, once you have more weight it will for sure alter the spring frequency, hence rougher rides and you might set yourself up for oscillations of your wheels, which is the preamble to DW.(be sure the tire pressure and balance is up to par)
Furthermore, a lift spacer (BB) will also reduce your caster.

My suggestion is to do a spring change lift instead of this BB (there are several lift kits on the market..) Be sure you have a complete kit (trackbars, shocks, control arms etc..)

Welcome to the forum..and enjoy ..
USAntigoon is offline   Reply With Quote Quick reply to this message
Unread 04-29-2009, 07:25 PM   #7
USAntigoon
Retired from Forum
2008 JK Wrangler 
 
Join Date: Jul 2008
Posts: 1,084
Quote:
Originally Posted by cybersniper View Post
Sorry for calling my Jeep a car, Im spanish and sometimes words come out wrong..............
Eduardo
Don't worry.. I am a Belgium American and live hear since 1975 and I still make language errors..
(a votre sante -- salud)
USAntigoon is offline   Reply With Quote Quick reply to this message
Unread 04-29-2009, 09:43 PM   #8
Prot
Web Wheeler
 
Prot's Avatar
2014 JK Wrangler 
 
Join Date: Feb 2007
Location: Lafayette, LA
Posts: 7,389
Quote:
Originally Posted by USAntigoon View Post
I believe you have added weight because of the diesel.. This "sag" has compressed your springs most probable beyond the initial soft ride (more coils windings are in compressed state). A spacer lift is OK providing you maintain the same stock weight, once you have more weight it will for sure alter the spring frequency, hence rougher rides and you might set yourself up for oscillations of your wheels, which is the preamble to DW.(be sure the tire pressure and balance is up to par)
Furthermore, a lift spacer (BB) will also reduce your caster.

My suggestion is to do a spring change lift instead of this BB (there are several lift kits on the market..) Be sure you have a complete kit (trackbars, shocks, control arms etc..)

Welcome to the forum..and enjoy ..
The budget boost is basically hockey pucks that do not alter spring rate. He has factory springs, which are appropriate for his factory installed diesel engine which many American Jeepers crave. Maybe I am misreading something here, but your statement seems to imply that the diesel engine was something the OP added, which is incorrect.

To the OP:

Make sure your front and rear axles are centered. Check your trackbars to ensure the bushings are not worn out. There have been a fair number of cases of factory trackbar bushings being broken/worn out prematurely. Check your allignment. You want a slight tow in. I do not know how much caster you should have for that lift, but once you find the correct spec, you obviously need to have it checked. Check your shocks. Defective shocks and / or broken shock mounts have been reported. Get your tires road force balanced.

They would not sell a budget boost lift if it was that detrimental to the vehicle, rendering it unsafe to drive. Numerous people have installed budget boost lifts without a problem. Make sure your coil springs are seated correctly. Check out the rest of your suspension for anything loose such as sway bar links.

What size tires and what tire pressure are you running? Overinflated tires can contribute to death wobble.
__________________
2014 Copperhead Pearl Unlimited Sahara in progress
Prot is offline   Reply With Quote Quick reply to this message
Unread 04-29-2009, 10:36 PM   #9
USAntigoon
Retired from Forum
2008 JK Wrangler 
 
Join Date: Jul 2008
Posts: 1,084
Quote:
Originally Posted by Prot View Post
The budget boost is basically hockey pucks that do not alter spring rate. He has factory springs, which are appropriate for his factory installed diesel engine which many American Jeepers crave. Maybe I am misreading something here, but your statement seems to imply that the diesel engine was something the OP added, which is incorrect.
Correct, as long as the weight hasn't been changed..I don't know whether he has the RIGHT springs installed..(wrangler 2008 parts show 19 different springs....)
The OP also stated It has a 2,5 TERAFLEX budget boost and the suspension is very stiff on the first few inches it jumps over bumps. That is why I made that comment..
USAntigoon is offline   Reply With Quote Quick reply to this message
Unread 04-30-2009, 06:32 AM   #10
harald-hans
Member
2008 JK Wrangler 
 
Join Date: Sep 2007
Location: Germany
Posts: 166
That`s the reason why I not bought a "standard" suspension kit for my diesel

For examplae - the European JK has three different springs to balance the weight correct - so the manufacturer of my suspension kit does consider this circumstance - as you can see in my signature my JK CRD is lifted about 3.5" and most of the suspension parts are changed.

Also the axles must be centered exactly and the whole allignment must be adjusted 100% !!!

I can drive without problem 100 mph and more (depending on the tires) without any vibration in the steering wheel.

Greetings from a satisfied "JK Diesel Driver"

harald-hans
__________________
'08 Rubi 2.8 CRD DETN8R Yellow - to see all mod`s click here !

Yellow RubiKong - Frontside / Yellow RubiKong - Backside
harald-hans is offline   Reply With Quote Quick reply to this message
Unread 04-30-2009, 09:05 AM   #11
USAntigoon
Retired from Forum
2008 JK Wrangler 
 
Join Date: Jul 2008
Posts: 1,084
harald=hans

Thanks for the feedback..( makes lot of sense..)
USAntigoon is offline   Reply With Quote Quick reply to this message
Unread 04-30-2009, 09:32 AM   #12
SoCalJK
Registered User
2007 JK Wrangler 
 
Join Date: Apr 2007
Location: Orange, California
Posts: 1,456
Adding an adjustable track bar seemed to resolve my DW after the lift. When I had the DW I removed the BB and it went away so it was definitely related to the lift. Put it back and added shocks - no change. Added the track bar and it is gone, well almost. Still a little shimmy but that is all. I also had the tow set to be at the max limit of tow-out.
__________________
2007 Sahara Unlimited
4x4, Auto, Jeep Green, Tow Package, Soft top, 3 inch spring lift, MBRP Catback
SoCalJK is offline   Reply With Quote Quick reply to this message
Unread 04-30-2009, 02:37 PM   #13
cybersniper
Registered User
2007 JK Wrangler 
 
Join Date: Apr 2009
Location: spain
Posts: 6
tell us more about your suspension

My rig came with the 2,8CRD FROM THE FACTORY and the ride was stiff since day one.
I have rotared front to rear the wheels today and some vibration has gone away.
I will try an adj. trackbar but dont know which one yet.

I may end up changing the front suspension and retiring the BB which has given me so many headaches.

ARE YOU HAPPY with yours???

Eduardo
Quote:
Originally Posted by harald-hans View Post
That`s the reason why I not bought a "standard" suspension kit for my diesel

For examplae - the European JK has three different springs to balance the weight correct - so the manufacturer of my suspension kit does consider this circumstance - as you can see in my signature my JK CRD is lifted about 3.5" and most of the suspension parts are changed.

Also the axles must be centered exactly and the whole allignment must be adjusted 100% !!!

I can drive without problem 100 mph and more (depending on the tires) without any vibration in the steering wheel.

Greetings from a satisfied "JK Diesel Driver"

harald-hans
cybersniper is offline   Reply With Quote Quick reply to this message
Unread 04-30-2009, 02:47 PM   #14
cybersniper
Registered User
2007 JK Wrangler 
 
Join Date: Apr 2009
Location: spain
Posts: 6
some more info

My JK is stock but for the BB. When i installed the sway bar links where not right and I had to weld some. The ones included touched the rear tyres.
No big deal to fix.
Then the DW thing for the last year. After changing Steering dampers it has gone away but then it is slowly returning..... with 25000 miles it nearly went into it doing 90mph and I just changed the damper for a new Skyjacker.

Sent to alighn and balance. better but a little vibration at 65mph.
A little better BUT still too shaky.

I measured the caster and it seems to be 2 degrees mesured on the "C" top. Not very accurate but could do no better.

Today I changed the wheels front to rear and saw that the front shocks (OEM with extensions) are nearly bottoming up whilethe Jeep is sitting still.

same goes for the rubber bump stop extensions. I will check that tomorrow on the ramp as it maybe the rubber that is contacting the axle and not allowing free movement of the shock or even the schosk bottoming out on small bumps .

Maybe thats why the car feels so stiff.....

Eduardo
Quote:
Originally Posted by Prot View Post
The budget boost is basically hockey pucks that do not alter spring rate. He has factory springs, which are appropriate for his factory installed diesel engine which many American Jeepers crave. Maybe I am misreading something here, but your statement seems to imply that the diesel engine was something the OP added, which is incorrect.

To the OP:

Make sure your front and rear axles are centered. Check your trackbars to ensure the bushings are not worn out. There have been a fair number of cases of factory trackbar bushings being broken/worn out prematurely. Check your allignment. You want a slight tow in. I do not know how much caster you should have for that lift, but once you find the correct spec, you obviously need to have it checked. Check your shocks. Defective shocks and / or broken shock mounts have been reported. Get your tires road force balanced.

They would not sell a budget boost lift if it was that detrimental to the vehicle, rendering it unsafe to drive. Numerous people have installed budget boost lifts without a problem. Make sure your coil springs are seated correctly. Check out the rest of your suspension for anything loose such as sway bar links.

What size tires and what tire pressure are you running? Overinflated tires can contribute to death wobble.
cybersniper is offline   Reply With Quote Quick reply to this message
Unread 05-01-2009, 08:40 AM   #15
OCBob
Member
 
OCBob's Avatar
2009 JK Wrangler 
 
Join Date: Feb 2009
Location: Ocean City, MD
Posts: 174
I have been reading all the info on this thread. I posted the same type of thread a couple of weeks ago. Lots of good info. I have been trying many of the suggestions posted. I am still having the problem. Yesterday it shook me into the lane next to me. I was only traveling about 35 and thank goodness there was no one next to me at the time. THIS IS DRIVING ME NUTS!!!! Any other suggestions? Here are the details.....

09 JK 4dr purchased end of Feb, DD, lifted 3rd week in March after a lot of reading, research and Q&A (mostly from this forum).

Teraflex 3" Lift
Teraflex Front Lower FlexArms
Rancho Steering Stabilizer
Bilstein Shocks 5100
JKS Track Bar
MT Classic Lock 17x9's
Nitto All Terran Graplers 34x12

Problem started immediately after lifting. I have adjusted tire pressures. I took jeep back to my mechanic, we put in on the lift and re-checked every nut and bolt. TWICE. We then made sure the steering wheel was dead nuts in line. Still had issue. I then came back to the forum and go more advice and so I added front lower flexarms. Then I had the jeep aligned which included CASTER adjustment.

Front Specs after adjustment:
Camber -0.8 / -0.7
Caster 5.6 / 5.6
Toe .09 / .12 = total toe of .20 and with a steer ahead of -.01

Rear Specs after adjustment:
Camber -0.6 / -0.5
Toe 0.07 / 0.23 = .30 total toe and -0.08 thrust angle

I still have the problem. I tried to reach out to teraflex yesterday for help. Hard to get someone on the phone yesterday. I will try again today. I did notice after some light wheeling Sunday, not rock crawling. Sand and mud. I had broke both of my teraflex front sway bars. I spoke to several people and they said it should not impact the wobble. I am guessing that is true because I had the wobble before they snapped. Sorry for such a long message but I could use some more help. After the adjustment, the caster seems to now be in line with suggested posts within this and other threads. But since I am not a mechanic and I am just learning about working on a jeep, I thought posting them one of you guys would have a greater understanding than I. I need to get ride of this WOBBLE. What can I try next??? As a new jeep owner, this is becoming a very time consuming/frustrating adventure. Any additional HELP or suggestions you guys may have would be greatly appreciated.
OCBob is offline   Reply With Quote Quick reply to this message
Reply

Quick Reply
Message:
Options

Register Now

In order to be able to post messages on the JeepForum.com forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Password
Please enter a password for your user account. Note that passwords are case-sensitive.
Password:
Confirm Password:
Email Address
Please enter a valid e-mail address for yourself.
Note: All free e-mails have been banned due to mis-use. (Yahoo, Gmail, Hotmail, etc.)
Don't have a non-free e-mail address? Click here for a solution: Manual Account Creation
Email Address:

Log-in

Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.


Thread Tools


Suggested Threads





Jeep, Wrangler, Cherokee, Grand Cherokee, and other models are copyrighted and trademarked to Jeep/Chrysler Corporation. JeepForum.com is not in any way associated with Jeep or the Chrysler Corp.