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-   -   Jeep Death wobble, any ideas? (https://www.jk-forum.com/forums/modified-jk-tech-2/jeep-death-wobble-any-ideas-350434/)

schmity 05-25-2019 12:24 AM

Jeep Death wobble, any ideas?
 
So to explain, i ordered an adjustable mammoth front track bar for my jeep since it has been lifted 2.5" and I figured a longer track bar wouldnt hurt. After installing the track bar I got what I imagine was a death wobble, as I virtually lost all control on the steering wheel and the car shook left and right all while triggering the ABS and ESP BAS systems followed by a nasty grinding noise as if metal components were smacking into each other as i braked. After slowing down it would fix itself but leave the systems on. So i tried tightening the track bar and seeing how I couldve installed it wrong, after some tests I couldnt figure it so I put back on the stock track bar. This greatly reduced the issue as the car was working perfectly fine before this change, although if I go over a bump or dip hard enough itll lose itself and begin to wobble again, although there is no grinding metal noise and the ABS and ESP BAS systems do not turn on either. Im not sure what couldve caused my suspension to begin wobbling as I figured the new track bar would only be a better version of the OEM track bar, but then the old track bar failed to do what it did (not cause death wobble) just the day before. Im going to be looking at all the suspension parts later today and check the track bar, tie rod, drag link, ball joints, and control arms for any significant play. Is there any other areas I should look at? Whats your best way of testing these parts? Also do you have ideas how this death wobble couldve occured when just prior to the new track bar it worked fine? Much appreciated for all your help!

nthinuf 05-25-2019 10:10 AM

If you go down to JK Member Writeups, then click into JK writeups, you'll find a good Deathwobble/Shimmy Diagnosis thread stuck right to the top.

Where does it sound like the grinding noise is coming from?

What did you torque the Trackbar bolts to? They need to be fairly tight. Go ahead and list the specific components that were installed with the lift so we know what you're working with.

schmity 05-25-2019 11:03 AM

So I check out the thread you directed me to and it was created by a guy I watched a video of last night diagnosing the death wobble, very helpful and informative to say the least. I just checked all my components today and the only thing I feel is a small clunk in the tie rod and drag link when shifting the tires from side to side. Track bar doesnt exhibit this behavior as it appears to work normally. Ball joints and control arms seemed fine as well. I have tightened the bolts on the track bar to the required specs (125 ft-lb), however the wobble would still occur so i tightened just slightly beyond that hoping that would fix it. I have a 2.5" lift on the jeep, the shocks, tires, sway bar, and steering stabilizer have been on for a bit over half a year and havent given me any real issue. Im taking it to a 4x4 mechanic on Tuesday to see if they can fix the issue (im really hoping they figure it out, as ive taken it to a different shop and two mechanics couldnt figure out what the issue was albeit they werent a 4x4 shop.)

resharp001 05-25-2019 12:49 PM

Ball joints probably crapped out after that first wobble with the new TB, and now that you have the old TB back on, the ball joints are causing the problem. I presume you have factory BJs, and if so, they are pos that can't handle a wobble. I've had a good bit of experience with wobbles. Very rarely is DL or a TR the main cause of issue IMO. Not saying they CAN'T be, but it's almost always TB and BJ related.

schmity 05-25-2019 01:46 PM


Originally Posted by resharp001 (Post 4342733)
Ball joints probably crapped out after that first wobble with the new TB, and now that you have the old TB back on, the ball joints are causing the problem. I presume you have factory BJs, and if so, they are pos that can't handle a wobble. I've had a good bit of experience with wobbles. Very rarely is DL or a TR the main cause of issue IMO. Not saying they CAN'T be, but it's almost always TB and BJ related.

Hmm okay I see, that sounds reasonable. It still leaves the question as why did it break with the first time with the new one on it. When I checked the ball joints (lifted the tire off the ground and used a shovel under it as a lever) at most there was a very small amount of vertical movement on the ball joints for the passenger side. Is it supposed to be ZERO movement or is small movement okay?
Also shook the tire holding the top and bottom of it for horizontal movement and there wasnt any.

resharp001 05-25-2019 03:00 PM

I can only guess maybe you didn't get those TB bolts torqued down to 125 ft lbs, or that the jam nut didn't get tightened, both of which could leave play in the TB. Once a wobbly starts, it reeks havoc in the whole system. The factory BJs have plastic internals, and one good wobble can make those go kaput. What did you use to tighten up the jam nut on the new adjustable TB? You definitely have those TB bolts torqued to 125 ft lbs right?

This is what the factory BJ has on top of the studs -
https://www.jeepswag.com/jeep_jk_bal...all_joints.jpg

If you have enough movement that you see the knuckle moving when you do that shovel test, it's not a great sign. Seeing it flex up due to the pressure is one thing, but if you see movement in the gap between the knuckle and the C, it's almost certainly bad.

dan3jeeps 05-25-2019 05:09 PM

2007 JK here.

I had death wobble with the stock everything up front. I replaced everything and I mean everything with aftermarket parts and followed every suggestion available to eliminate my death wobble. Even my Jeep mechanic could not explain why I still had death wobble. Random and totally unexplained... DW sometimes without reason. I was ready to push this thing off a cliff.

My D30 finally came apart so I replaced it with a TF D44. No more death wobble. Hmm. Not even a slight front end shudder since I installed a better axle 2 years ago.

schmity 05-26-2019 06:47 PM


Originally Posted by resharp001 (Post 4342738)
I can only guess maybe you didn't get those TB bolts torqued down to 125 ft lbs, or that the jam nut didn't get tightened, both of which could leave play in the TB. Once a wobbly starts, it reeks havoc in the whole system. The factory BJs have plastic internals, and one good wobble can make those go kaput. What did you use to tighten up the jam nut on the new adjustable TB? You definitely have those TB bolts torqued to 125 ft lbs right?

This is what the factory BJ has on top of the studs -
https://www.jeepswag.com/jeep_jk_bal...all_joints.jpg

If you have enough movement that you see the knuckle moving when you do that shovel test, it's not a great sign. Seeing it flex up due to the pressure is one thing, but if you see movement in the gap between the knuckle and the C, it's almost certainly bad.

Then it should be the ball joints, cant figure what else it could be tbh. Coming to think of it the one worry I have is that when I installed it I did use a torque wrench but its coming up foggy if I did 125 Newton-meters or Foot-pounds (which is a large difference), so im thinking that maybe I just tightened it on Newton-meters and not Foot-pounds. Im getting jeep fixed tuesday however with a whole swap of the front suspension and ball joints and hope that thatll fix it. Will keep you updated, thanks for the help troubleshooting, I really appreciate it.

schmity 05-26-2019 06:58 PM


Originally Posted by dan3jeeps (Post 4342745)
2007 JK here.

I had death wobble with the stock everything up front. I replaced everything and I mean everything with aftermarket parts and followed every suggestion available to eliminate my death wobble. Even my Jeep mechanic could not explain why I still had death wobble. Random and totally unexplained... DW sometimes without reason. I was ready to push this thing off a cliff.

My D30 finally came apart so I replaced it with a TF D44. No more death wobble. Hmm. Not even a slight front end shudder since I installed a better axle 2 years ago.

Yeah its a pain to have a death wobble, I havent wanted to drive the jeep because I dont want to do any more potential damage. That being said I really hope its not the axle, truly thats a first for me hearing that be the fix lol. Glad it worked for you though, will keep you updated on the fix. Thanks for the help!

resharp001 05-27-2019 11:13 AM


Originally Posted by schmity (Post 4342761)
I really hope its not the axle

It is not the axle, don't worry. Consider this a good opportunity to get associated with your steering system. TB and BJ's are 85% of the issues. Bad DL ends will give you some bump steer (hit a bump/pothole and the wheel jerks once), and bad TRE is similar. In very extreme cases on older, high mileage vehicles, wheel bearings may come in to play...and nothing is helped if someone is running low caster due to a lift. Unless you are out wheeling a factory axle balls to the wall and bend the C's so bad it jacks with the ball joints, or the jeep has been in accident that bent the tubes or Cs, I don't see how an axle can come in to play at all except having things attached to the axle that are undertorqued or possibly axle-side TB bracket hole wallowed out, but that usually happens on the frame side. Could it be possible?....guess there are ways it could be, but it is highly, HIGHLY unlikely you ever encounter the axle itself coming in to play in regards to DW.

On a side note, you usually have tight steering after replacing ball joints until they wear in, 500 miles or so. It might feel like you're constantly having to correct the steering, especially at lower speeds it might feel hard to stay in the lane. Don't fret and just give it a little time.


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