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-   -   Now it's death wobble... (http://www.wranglerforum.com/f274/now-its-death-wobble-205887.html)

Six 12-17-2012 08:18 AM

Now it's death wobble...
 
So after my previous thread of diagnosing non death wobble I had an alignment done by a local 4x4 shop. They said the toe was so far out that the tires would fight each other. What was happening is that larger bumps over 55mph had the possibility to cause the front to start shimmying and it wouldn't stop until you slowed to under 55mph. The evening after I had my alignment done, I drove from the Eastern panhandle of WV to Hershey, PA in the interstate and had no issue. One the way home the next day, still no issues.

A few days after this I was on the way to pick up rubi rails about 40 miles from where I live on a road that has a speed limit of 65 and is a bit twistier than my other interstate trip. I experience death wobble. This happened after hitting a large bump at a bridge joice in the middle of a turn going 70mph. I had to come to nearly a complete stop. This happened again three days later under the exact sam condition on another road. Both times the road was curving right.

I contacted the 4x4 shop after the first incident and they said to fix it, I would need adjustable upper control arms to put the caster in to spec. However, before I left he said everything was in spec except for the caster. I was told that it was only about .1-.3 of a degree out and that it shouldn't affect anything since it was out in the "correct" direction and that the Rock Krawler adjustable lowers were adjusted as short as they could go.

So, the Jeep has less than 7K miles on it and all the stock hardware upfront should be good. It's aligned and in spec except with the caster being out only a bit. The wobble was originally a shimmy before the alignment and after the alignment it's now a full on death wobble. This didn't start until after the Rock Krawler 2.5" Flex kit was installed.

I've read through the diagnosing death wobble threads and they all point to adjusting the track bar. The one time I tried that, I couldn't find a place to measure to as the tires are stock and tucked inside the fender. If everything is supposedly aligned and adjusted to spec, what gives? Any ideas on where to look?

cocky grin 12-17-2012 08:21 AM

Quote:

Originally Posted by Six
So after my previous thread of diagnosing non death wobble I had an alignment done by a local 4x4 shop. They said the toe was so far out that the tires would fight each other. What was happening is that larger bumps over 55mph had the possibility to cause the front to start shimmying and it wouldn't stop until you slowed to under 55mph. The evening after I had my alignment done, I drove from the Eastern panhandle of WV to Hershey, PA in the interstate and had no issue. One the way home the next day, still no issues.

A few days after this I was on the way to pick up rubi rails about 40 miles from where I live on a road that has a speed limit of 65 and is a bit twistier than my other interstate trip. I experience death wobble. This happened after hitting a large bump at a bridge joice in the middle of a turn going 70mph. I had to come to nearly a complete stop. This happened again three days later under the exact sam condition on another road. Both times the road was curving right.

I contacted the 4x4 shop after the first incident and they said to fix it, I would need adjustable upper control arms to put the caster in to spec. However, before I left he said everything was in spec except for the caster. I was told that it was only about .1-.3 of a degree out and that it shouldn't affect anything since it was out in the "correct" direction and that the Rock Krawler adjustable lowers were adjusted as short as they could go.

So, the Jeep has less than 7K miles on it and all the stock hardware upfront should be good. It's aligned and in spec except with the caster being out only a bit. The wobble was originally a shimmy before the alignment and after the alignment it's now a full on death wobble. This didn't start until after the Rock Krawler 2.5" Flex kit was installed.

I've read through the diagnosing death wobble threads and they all point to adjusting the track bar. The one time I tried that, I couldn't find a place to measure to as the tires are stock and tucked inside the fender. If everything is supposedly aligned and adjusted to spec, what gives? Any ideas on where to look?

Just gonna throw this out there but look at your steering stabilizer I replaced mine and my wobble issues went away

Six 12-17-2012 08:29 AM

Quote:

Originally Posted by cocky grin (Post 3113028)
Just gonna throw this out there but look at your steering stabilizer I replaced mine and my wobble issues went away

I've read that the stabilizer will just help to mask the problem and that you shouldn't need one. If that is the case, I'd like to try and get it corrected properly before going that route.

If that doesn't work, which stabilizer are you running?

cocky grin 12-17-2012 08:35 AM

Quote:

Originally Posted by Six

I've read that the stabilizer will just help to mask the problem and that you shouldn't need one. If that is the case, I'd like to try and get it corrected properly before going that route.

If that doesn't work, which stabilizer are you running?

Just a stock replacement I got at autozone but then again my jk is an 07 and the SS I took off was completely dead so if that had anything to do with causing wobble idk but it seems possible

cocky grin 12-17-2012 08:37 AM

Just reread that I'd your jeep is new i would just rule out the steering stabilizer

DJL2 12-17-2012 08:42 AM

Six,

The thing about death wobble, or other violent oscillation, is that it tends to be self propagating. The stress placed on the parts can cause premature wear and actually push them out of spec, if they are not already, and lead to more issues.

Were I in your shoes, I'd definitely pull the track bar and take a look at what you're working with there. I'd be tempted to take a look at my control arms as well. You'll definitely want to confirm that all your torque settings are correct.

As far as measuring for your track bar, you can do it like this:

1.) identify a clear landmark on the wheel/tire/joint; something that you can easily find on both sides and which will be equivalent on both sides.

2.) find a clear landmark on your frame; you can use something precisely in the middle or you can use an identical landmark on each side.

3.) measure the distance on both sides; if you're seeing a difference here that's an indicator that you're not centered.

That'll work even if you're still under the fenders. Also, you'll want to leave the track bar in place for that bit. If you have an adjustable track bar, all you need is a ratchet strap to move the Jeep relative the axle to where it's centered; re-install track bar and done.

It'll be tough to get a warm fuzzy feeling. I still check mine. I want it to be accurate to .0000000001 inches (exaggerated, I know) - it's difficult to get super accuracy without being a bit more elaborate: using a plumb bob, taping things off, levels, string, etc.

clvnmcd 12-17-2012 08:46 AM

Here's how I found the culprit of my death wobble. I unhooked the Steering stabilizer and watched under the jeep while the wife rocked the steering wheel back and four (10 to 2). At that time I could see where the stock trackbar was flexing. Both ends of the trackbar were tight and properly torqued, but the bar itself was flexing at the bow over the differential. Replacing the stock bar with a heavier stronger aftermarket trackbar, fixed it completely up. It's almost always the trackbar, especially on a newer jeep where you just haven't had time to wear out ball joints or tie rod ends.

Six 12-17-2012 08:52 AM

Quote:

Originally Posted by DJL2 (Post 3113084)
Six,

The thing about death wobble, or other violent oscillation, is that it tends to be self propagating. The stress placed on the parts can cause premature wear and actually push them out of spec, if they are not already, and lead to more issues.

Were I in your shoes, I'd definitely pull the track bar and take a look at what you're working with there. I'd be tempted to take a look at my control arms as well. You'll definitely want to confirm that all your torque settings are correct.

As far as measuring for your track bar, you can do it like this:

1.) identify a clear landmark on the wheel/tire/joint; something that you can easily find on both sides and which will be equivalent on both sides.

2.) find a clear landmark on your frame; you can use something precisely in the middle or you can use an identical landmark on each side.

3.) measure the distance on both sides; if you're seeing a difference here that's an indicator that you're not centered.

That'll work even if you're still under the fenders. Also, you'll want to leave the track bar in place for that bit. If you have an adjustable track bar, all you need is a ratchet strap to move the Jeep relative the axle to where it's centered; re-install track bar and done.

It'll be tough to get a warm fuzzy feeling. I still check mine. I want it to be accurate to .0000000001 inches (exaggerated, I know) - it's difficult to get super accuracy without being a bit more elaborate: using a plumb bob, taping things off, levels, string, etc.

Is the spring perch going to be the same on both sides? If not, any suggestions on where to measure to? I want to try this.

Quote:

Originally Posted by clvnmcd (Post 3113099)
Here's how I found the culprit of my death wobble. I unhooked the Steering stabilizer and watched under the jeep while the wife rocked the steering wheel back and four (10 to 2). At that time I could see where the stock trackbar was flexing. Both ends of the trackbar were tight and properly torqued, but the bar itself was flexing at the bow over the differential. Replacing the stock bar with a heavier stronger aftermarket trackbar, fixed it completely up. It's almost always the trackbar, especially on a newer jeep where you just haven't had time to wear out ball joints or tie rod ends.

I have the adjustable track bar that came in the Rock Krawler kit. It's pretty friggin' beefy.

clvnmcd 12-17-2012 08:59 AM

Quote:

Originally Posted by Six (Post 3113123)
Is the spring perch going to be the same on both sides? If not, any suggestions on where to measure to? I want to try this.



I have the adjustable track bar that came in the Rock Krawler kit. It's pretty friggin' beefy.

Same one I have, you can definitely rule out the track bar flexing, cause it would take 3 men and a mule to budge that thing.... Maybe the ends????

Six 12-17-2012 09:03 AM

Quote:

Originally Posted by clvnmcd (Post 3113144)
Same one I have, you can definitely rule out the track bar flexing, cause it would take 3 men and a mule to budge that thing.... Maybe the ends????

Tie rod? But it has less than 7k miles and didn't start until after the kit was installed.

Blkfenderslookbetter 12-17-2012 09:03 AM

What wheels & tires did you do after the lift?

Are your rims hubcentric?

clvnmcd 12-17-2012 09:07 AM

Quote:

Originally Posted by Six (Post 3113157)
Tie rod? But it has less than 7k miles and didn't start until after the kit was installed.

Shouldn't be a Tie Rod end, it's really too new to wear those out. What kind of tire pressure are you currently at? My tire pressure was too high once and it made accentuated the death wobble. Check the ends of the trackbar to make sure they don't move on you as well.

planman 12-17-2012 09:10 AM

Have you watched my two videos in addition to reading the first couple posts in my diagnosis thread?

Six 12-17-2012 10:13 AM

Quote:

Originally Posted by Blkfenderslookbetter (Post 3113158)
What wheels & tires did you do after the lift?

Are your rims hubcentric?

Stockers.

Quote:

Originally Posted by clvnmcd (Post 3113169)
Shouldn't be a Tie Rod end, it's really too new to wear those out. What kind of tire pressure are you currently at? My tire pressure was too high once and it made accentuated the death wobble. Check the ends of the trackbar to make sure they don't move on you as well.

35 psi.

Quote:

Originally Posted by planman (Post 3113174)
Have you watched my two videos in addition to reading the first couple posts in my diagnosis thread?

I've only read through the thread, haven't watched the videos yet.

clvnmcd 12-17-2012 10:46 AM

[QUOTE=Six;3113325]Stockers.



35 psi.

Maybe try dropping the pressure a few psi and see if that changes anything.

Six 12-17-2012 11:07 AM

[QUOTE=clvnmcd;3113407]
Quote:

Originally Posted by Six (Post 3113325)
Stockers.



35 psi.

Maybe try dropping the pressure a few psi and see if that changes anything.

How much? I know 35 is the OEM tires rating from Jeep.

Plasticpirogue 12-17-2012 11:31 AM

[QUOTE=Six;3113462]
Quote:

Originally Posted by clvnmcd (Post 3113407)

How much? I know 35 is the OEM tires rating from Jeep.

I run mine at 32-33psi on the 255s...it's a little smoother too. 30 is even smoother, but you are increasing rolling resistance too much IMO so I don't go below 32.

kjeeper10 12-17-2012 11:37 AM

Sorry about your mess :(


I just found out my PSI gauge was 5 psi off.
I was riding around 32-37 psi on a 35 :eek:

Not DW but all kinds of other issues.

Caster should be around 5 with RK's settings. That's fine with a stock DS.
Double carden will need less for more pinion up.

Did you toe out of spec wear the tires funny? That could cause problems.

Ken

Six 12-17-2012 11:42 AM

Quote:

Originally Posted by kjeeper10 (Post 3113545)
Sorry about your mess :(


I just found out my PSI gauge was 5 psi off.
I was riding around 32-37 psi on a 35 :eek:

Not DW but all kinds of other issues.

Caster should be around 5 with RK's settings. That's fine with a stock DS.
Double carden will need less for more pinion up.

Did you toe out of spec wear the tires funny? That could cause problems.

Ken

Only put like maybe 200 miles on the tires before they were properly aligned.

Anyone else have the 2.5" Flex kit on an otherwise stock JKU?

kjeeper10 12-17-2012 01:17 PM

A a newer 12 with the proper alignment and DW. All my focus would be on the front TB.

Six 12-17-2012 01:28 PM

Quote:

Originally Posted by kjeeper10 (Post 3113873)
A a newer 12 with the proper alignment and DW. All my focus would be on the front TB.

I'll measure it then remove it and inspect it.

mackdj1 12-17-2012 01:31 PM

Make sure the bolt that holds the track bar on is a snug fit. Any play even if it seems small could cause a wobble. Where your rig is new this is unlikely but should still be checked.

Atomic Decals Owner 12-17-2012 01:47 PM

I had a wobble/ high speed shimmy this summer. Everything on the checklist seemed fine. Changed out worn steering stabilizer with a new stock one, and had all 4 wheels/tires balanced and rotated (front 2 were way out of balance.) Cleared up the problem for me.

CombatChuk 12-17-2012 05:09 PM

What was your caster up front measured at?

Six 12-17-2012 07:35 PM

Quote:

Originally Posted by CombatChuk (Post 3114621)
What was your caster up front measured at?

I'll have to find out. The guy at the 4x4 shop said it was .1-.3 in the "good" side out of alignment.

kjeeper10 12-17-2012 07:50 PM

Quote:

Originally Posted by Six

I'll have to find out. The guy at the 4x4 shop said it was .1-.3 in the "good" side out of alignment.

Caster is in degrees
Stock is about 4.2*

Lifting decreases a little bit but not much.
Maybe 3*

CA's should easily adjust caster back to stock or a little more. some will bump it up to 5* or 6* but this decreases the pinion angle.
With the stock DS you really don't have to worry about pinion unless at 4" of lift height or a aftermarket DS.

You should be OK at 5*


Toe in should be about 1/8

microage97 12-18-2012 02:49 PM

Got the wobble as well after 60 mile sin 18" deep snow. 49K on a new to me 08 X with Rubi wheels. Took it to the dealer as I have an aftermarket warranty to find out the steering stabilizer is leaking and not covered. :-( I believe the wobble was caused from the snow packed wheels. Got all of that out and will a wobble once in a great while so I took it to the dealer for service. They want 295.00 to replace it and I told them no. 62.00 for a Rancho RS5000 and 15.00 for a puller.

chopperbobby 12-18-2012 11:15 PM

I got mine after having a 2" bds lift installed. over a year ago. scared the bajesus out of me. i still am gun shy when I go over big bumps.

First Fix worked for a month steering stabilizer was loose.

month later dw.

Followed advice from many different forums and Loosened all the bolts. lower and upper control arms, track bar while the jeep was on the ground. Jumped on the bumper a few times then re torqued all. Got a front end alignment. 9 months and no problems.

Six 12-19-2012 08:42 AM

Quote:

Originally Posted by chopperbobby (Post 3120257)
I got mine after having a 2" bds lift installed. over a year ago. scared the bajesus out of me. i still am gun shy when I go over big bumps.

First Fix worked for a month steering stabilizer was loose.

month later dw.

Followed advice from many different forums and Loosened all the bolts. lower and upper control arms, track bar while the jeep was on the ground. Jumped on the bumper a few times then re torqued all. Got a front end alignment. 9 months and no problems.

Been there. Done that.

Con Artist 12-19-2012 09:20 AM

Who did the work, Will?


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