Will the ZJ steering mod help death wobble?

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Frankred

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I have an occasional light wobble around 40mph. I have 41k on my 2004 sport Auto. I have 600 miles on my KO2s. I had it before the KO2s. I have a recent OME steering stabilizer. It helped. I'm just wondering if the ZJ steering upgrade would have a good shot at reducing the issue.
Thanks,
John
 
CodaMan said:
At what speeds does it wobble (from what to what)? Is it always at the same speeds? Do you feel it in the steering wheel?
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It wobbles from 40 to 45. I can feel and see it in the steering wheel. I suspect it might happen at highway speeds too but it isn't as evident.
I can say I rotated the passenger side the other day front to rear and it didn't change it. I need to rotate the driver side tires to see if that changes it.
 
Frankred said:
It wobbles from 40 to 45. I can feel and see it in the steering wheel. I suspect it might happen at highway speeds too but it isn't as evident.
I can say I rotated the passenger side the other day front to rear and it didn't change it. I need to rotate the driver side tires to see if that changes it.
Click to expand...

I would almost guarantee it's a wheel not balanced perfectly , even if the tire shop says they are. Swap wheels front to back and see what happens.
 
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Before I tried rotating the driver's side tires, I took my first try at checking alignment. If I'm doing it right, I'm seeing 53" 15/16 and 54” and 3/16. I'm reading on the stick that is too much.

I'll rotate the driver's side and try to get some square tube or din rail to check it again. I'll rotate the driver's side now.

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@Hog and I fixed one Friday evening that had death wobble by upgrading the track bar and axle end track bar bushing and bolt. Then we slapped on a ZJ tie rod end for the trail durability and ability to last longer with large tires.

Your out of toe front is going to make it wander and eat your tires . You want to be toed in about 1/8”.

Dry test the steering ( have someone move the steering wheel from 10-2 and watch every connection as you change directions)

A ZJ upgrade replaces 2 ends , so if one or both is bad , you will be better off, and you get a bigger tie rod and a stouter outer end (Moog # ES3096 L, same size as the big one at the pitman arm). The cases the ZJ change cures it , only cured it because the upgrade included new ends they needed.

Most likely your tires need balanced a little better, rotating usually proves that , and your track bar bushings have some slop or are loose. Typically tires cause it and the track bar bushing or other parts allow the oscillation. Be sure to catch that , it’s important to understand.

if it does it at speed , that’s the speed it takes to get the tire wonky enough to set it off ...but usually still the track bar needs attention. My F250 would do it at 78. Not what you want. In that case , it was the track bar , tires were decent ...up to 78 mph.

My TJ would do it with a bump...that meant my tires were near perfect ...and my track bar bushing was the culprit.

I like to run an Energy Suspension polyurethane track bar bushing at the axle mount with the steel sleeve they provide and a 12mm bolt at the axle, vs. the stock 10mm.

I have 12.5 x 33 KO 2 tires my 03, they are great and out drive my cooper sst pros on my 06....... scaling the front end linkage for big tires makes total sense.

If you are thorough , it ends up being better off road and on. That has really been my experience.
 
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AndyG said:
@Hog and I fixed one Friday evening that had death wobble by upgrading the track bar and axle end track bar bushing and bolt. Then we slapped on a ZJ tie rod end for the trail durability and ability to last longer with large tires.

Your out of toe front is going to make it wander and eat your tires . You want to be toed in about 1/8”.

Dry test the steering ( have someone move the steering wheel from 10-2 and watch every connection as you change directions)

A ZJ upgrade replaces 2 ends , so if one or both is bad , you will be better off, and you get a bigger tie rod and a stouter outer end (Moog # ES3096 L, same size as the big one at the pitman arm). The cases the ZJ change cures it , only cured it because the upgrade included new ends they needed.

Most likely your tires need balanced a little better, rotating usually proves that , and your track bar bushings have some slop or are loose. Typically tires cause it and the track bar bushing or other parts allow the oscillation. Be sure to catch that , it’s important to understand.

if it does it at speed , that’s the speed it takes to get the tire wonky enough to set it off ...but usually still the track bar needs attention. My F250 would do it at 78. Not what you want. In that case , it was the track bar , tires were decent ...up to 78 mph.

My TJ would do it with a bump...that meant my tires were near perfect ...and my track bar bushing was the culprit.

I like to run an Energy Suspension polyurethane track bar bushing at the axle mount with the steel sleeve they provide and a 12mm bolt at the axle, vs. the stock 10mm.

I have 12.5 x 33 KO 2 tires my 03, they are great and out drive my cooper sst pros on my 06....... scaling the front end linkage for big tires makes total sense.

If you are thorough , it ends up being better off road and on. That has really been my experience.
Click to expand...
I rotated the driver's side tires and took a quick 3 mile test drive. I didn't experience any wobble, though I'll still watch out for it over the next few days. I looked up the Energy Suspension track bar bushing, 2.7102, and found it on Amazon. I'll consider that as an easy next step. If the wobble doesn't reappear, I'll go get my tires balanced and ask for a report on their findings.
 
Normally, switching an unbalanced tire from one side to the other just moves the shake. To really verify you would move both front wheels to the rear, but maybe i'll work and tell you everything you need to know.
 
CodaMan said:
Normally, switching an unbalanced tire from one side to the other just moves the shake. To really verify you would move both front wheels to the rear, but maybe i'll work and tell you everything you need to know.
Click to expand...
This evening I swapped driver's side front to back. I swapped passenger side front to back early last week.
That said, I'd like to see some more miles with no issues before I go have a tire shop check balance.

If I see more issues, I'll go get some square tube or din rail to check alignment with.
 
Frankred said:
I rotated the driver's side tires and took a quick 3 mile test drive. I didn't experience any wobble, though I'll still watch out for it over the next few days. I looked up the Energy Suspension track bar bushing, 2.7102, and found it on Amazon. I'll consider that as an easy next step. If the wobble doesn't reappear, I'll go get my tires balanced and ask for a report on their findings.
Click to expand...
Remember a track bar has 2 ends ..,can be either or both. I have seen a loose frame mount bolt create a headache . And it can be other components or a combination of several.

Don’t take this as negative or elusive..it is usually something you can see and remedy .
 
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Get that toe in set correctly. If I read it right you have a 1/2" of toe. You should get that to 1/8". Maybe a hair more or less when you fine tune it. Until then you have the steering system fighting itself trying to decide which tire to track straight.
Do a dry steering test. Any, ANY movement or play in any rod end needs to be replaced. If that is so, then this is a good time for a ZJ steering upgrade. All new tierod parts will let you set the toe in nice and easy.
 
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Frankred said:
I have an occasional light wobble around 40mph.
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A light speed-sensitive wobble is definitely not Death Wobble. Death Wobble is aptly named, it is VIOLENT and your Jeep feels like it's going out of control. The only way to stop it is to come to nearly a complete stop. It is violent beyond your ability to comprehend until you have personally experienced it. Other drivers will even notice your Jeep is shaking like a giant hand has taken hold of it and is shaking it like a martini shaker.

Speed sensitive wobbles are usually always tire related, as in the balance isn't good enough... even if recently balanced. Some shops don't always give their techs enough time to perfectly balance tires like the type of front-end the TJ has requires. I have had to take my Jeep back in twice the same day after the initial balance before they finally figured out they had to get the balance perfect or I'd come back again.
 
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Jerry Bransford said:
A light speed-sensitive wobble is definitely not Death Wobble. Death Wobble is aptly named, it is VIOLENT and your Jeep feels like it's going out of control. The only way to stop it is to come to nearly a complete stop. It is violent beyond your ability to comprehend until you have personally experienced it. Other drivers will even notice your Jeep is shaking like a giant hand has taken hold of it and is shaking it like a martini shaker.

Speed sensitive wobbles are usually always tire related, as in the balance isn't good enough... even if recently balanced. Some shops don't always give their techs enough time to perfectly balance tires like the type of front-end the TJ has requires. I have had to take my Jeep back in twice the same day after the initial balance before they finally figured out they had to get the balance perfect or I'd come back again.
Click to expand...
I should have left out "death" in the title. I have been home so far today. I'm hoping to find no more occasional light wobbles and then have the tires balanced.
 
Jerry Bransford said:
A light speed-sensitive wobble is definitely not Death Wobble. Death Wobble is aptly named, it is VIOLENT and your Jeep feels like it's going out of control. The only way to stop it is to come to nearly a complete stop. It is violent beyond your ability to comprehend until you have personally experienced it. Other drivers will even notice your Jeep is shaking like a giant hand has taken hold of it and is shaking it like a martini shaker.

Speed sensitive wobbles are usually always tire related, as in the balance isn't good enough... even if recently balanced. Some shops don't always give their techs enough time to perfectly balance tires like the type of front-end the TJ has requires. I have had to take my Jeep back in twice the same day after the initial balance before they finally figured out they had to get the balance perfect or I'd come back again.
Click to expand...
Good post ..speed sensitive wobbles can trigger death wobble if you have loose components , and I think they can create premature wear of steering components if allowed to go unchecked. It seems 40-50 mph is the magic zone for those .

if you get death wobble, it’s like a heart attack....you will know something potentially fatal is happening....even the first time. You will think of nothing else on earth but how to safely stop. You will not be able to drive a needle up your butt with a sledgehammer.
 
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Fixing the vibration is no reason not to upgrade your steering with all of the ZJ upgrade components. Do the drag link as well and ball joints too if required.

I don't wait for steering, tires or brake components to wear out before I replace them. I consider them maintenance items and keep them in tip top fighting form. Its only money.
 
I did not have the 40mph wobble today. However, it still feels like there is a mild chaos going on below the vehicle at highway speeds.

I bought some 3/8in x 1/2in 1/16th aluminum c channel this afternoon (pretty delicate once I tried it out. I'd suggest something more substantial) for 2x $12 and checked my alignment. It is almost 1/8" closer in front but not quite.

Hmm. Since rotating seems to have helped the wobble. Tire balance time?
 
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