Can dropped pitman arms prevent death wobble?

Tob

Tob

Paint-Matched Bezels Club
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In almost 2 years, I’ve put ~19k miles on this Jeep and have never had death wobble. After some recent changes, it now happens very often. On my way up to hot springs last night I lost count of how many times I got DW.

Those recent changes were:

Pitman arm swapped from dropped to OEM

1.25” BL

1” MML

Fuel pump changed

Alignment done

Tires rotated

I started getting death wobble before the alignment and rotation, which I thought would fix the issue since I had excessive toe-in, but if anything it happens more now.

I am trying to narrow down what’s causing the DW and correct it ASAP. Losing control of the vehicle and having to slam the brakes to a near stop to regain it (on the interstate) is absolutely unacceptable.

My question is, has anyone else experienced death wobble after changing from a dropped pitman arm to an OEM? I can’t imagine that the motor or body lift would cause me to suddenly get death wobble all the time. The pitman arm is the only steering-related component I changed.
 
Does the track bar have a drop mount on the frame side? Take pics of your front suspension setup
 
Do you have a dropped trackbar mount?
Or some non-stock steering geometry? Take photos if you're unsure.

Also, do you have the final alignment numbers? If the caster or toe is set incorrectly, it can cause issues.
 
SecondChanceTJ said:
In almost 2 years, I’ve put ~19k miles on this Jeep and have never had death wobble. After some recent changes, it now happens very often. On my way up to hot springs last night I lost count of how many times I got DW.

Those recent changes were:

Pitman arm swapped from dropped to OEM

1.25” BL

1” MML (Motor Mount Lift)

Fuel pump changed

Alignment done

Tires rotated

I started getting death wobble before the alignment and rotation, which I thought would fix the issue since I had excessive toe-in, but if anything it happens more now.

I am trying to narrow down what’s causing the DW and correct it ASAP. Losing control of the vehicle and having to slam the brakes to a near stop to regain it (on the interstate) is absolutely unacceptable.

My question is, has anyone else experienced death wobble after changing from a dropped pitman arm to an OEM? I can’t imagine that the motor or body lift would cause me to suddenly get death wobble all the time. The pitman arm is the only steering-related component I changed.
Click to expand...
You need to describe your Jeep a bit more pre pitman arm change.
 
SecondChanceTJ said:
In almost 2 years, I’ve put ~19k miles on this Jeep and have never had death wobble. After some recent changes, it now happens very often. On my way up to hot springs last night I lost count of how many times I got DW.

Those recent changes were:

Pitman arm swapped from dropped to OEM

1.25” BL

1” MML (Motor Mount Lift)

Fuel pump changed

Alignment done

Tires rotated

I started getting death wobble before the alignment and rotation, which I thought would fix the issue since I had excessive toe-in, but if anything it happens more now.

I am trying to narrow down what’s causing the DW and correct it ASAP. Losing control of the vehicle and having to slam the brakes to a near stop to regain it (on the interstate) is absolutely unacceptable.

My question is, has anyone else experienced death wobble after changing from a dropped pitman arm to an OEM? I can’t imagine that the motor or body lift would cause me to suddenly get death wobble all the time. The pitman arm is the only steering-related component I changed.
Click to expand...
It’s not the OEM pitman arm.

It’s not the BL

It’s the combination of the MML, the tires, and something else like trackbar at the axle or tie rod ends.

The MML can surface other problems because the position of the engine changes the rigidity.

Try toe out and see if it’s any better.
 
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Ok...I re-read your post.

"I started getting death wobble before the alignment and rotation, which I thought would fix the issue since I had excessive toe-in, but if anything it happens more now."

Most ...not all..but most DW issues are track bar issues.

IMO you have a simple 3 inch lift...put a dropped pitman arm on...and was ok with it. (Luckily)

Then...your track bar fittings wore out and low and behold...DW shows up.

Get a new QUALITY track bar and I'd bet your DW issues go away.

Good luck
 
Jodh said:
Does the track bar have a drop mount on the frame side? Take pics of your front suspension setup
Click to expand...
Stock track bar and mounting locations
Steel City 06 said:
Do you have a dropped trackbar mount?
Or some non-stock steering geometry? Take photos if you're unsure.

Also, do you have the final alignment numbers? If the caster or toe is set incorrectly, it can cause issues.
Click to expand...
Using the aluminum square tube method, 1/8 inch toe in 18 inches in front of the axle. Caster never changed.
 
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JMT said:
It’s not the OEM pitman arm.

It’s not the BL

It’s the combination of the MML (Motor Mount Lift), the tires, and something else like trackbar at the axle or tie rod ends.

The MML (Motor Mount Lift) can surface other problems because the position of the engine changes the rigidity.

Try toe out and see if it’s any better.
Click to expand...
What specifically about the tires could be the issue? Bad wear pattern? And what about the track bar or tie rod ends? Loose connections?
 
Death Wobble is simply auto oscillation of the front tires and linkage.

It can be broken into two components...that can be independent or interdependent in any ratio-

1. Death Wobble from cause - this can be a low tire, an imbalanced tire (very common) a bad tire,a broke belt,a bad wheel, I've even known of a bad brake rotor. This will happen at a certain speed generally. 45-55 being common. In this scenario, everything is tight, it is just being overpowered by the force that is causing it.

2. Passive Death Wobble- this is worn components that tend to allow the vehicle to track but can't overcome the force a bump or impact generates to stabilize the front tires after the bump. Worn track bar bushings, loose track bars, loose/worn tie rod ends and hub unit bearings can all allow this. So within this realm it can be one loose/worn thing or several barely loose adding up. Basically the components are ALLOWING everything to oscillate, regardless of cause.

This can also present itself at a certain higher speed.....well balanced tires May not generate enough harmonic until they get to a higher rate of speed ..my F250 would do it at 78 mph...but it was the track bar bushings. Really a bad time to have it. It was fine til then, as it was "tight enough" to handle the forces until they got the upper hand . It's give and take....a new bushing solved it til I sold it 175,000 miles later.

I'm not trying to make it complicated or confusing..it's generally only so many things - but first if you isolate whether it's 1 or 2 it can be easier to diagnose....

Just remember it can be some of both , and if it's in the second category...it can be anything from one loose bolt to nearly everything up front....and any thing in between.

It's not that elusive . Stuffs moving that shouldn't or will allow movement it shouldn't.

And No I don't think it's the pitman arm or the lift .....but ultimately I do think it's something up front like tires or connections..don't underrate the control arms either.... especially the upper front passenger side.

Have a friend turn the wheel from 10-2 and watch the linkage..ask @Hog he can attest this will reveal things.
 
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SecondChanceTJ said:
What specifically about the tires could be the issue? Bad wear pattern? And what about the track bar or tie rod ends? Loose connections?
Click to expand...
My situation was a lot like you’re in that the day I installed the MML, I got DW.

The tires could be out of balance or out of round. I literally had my 31” GY MTR’s balanced 3 times, each time stressing they need to be perfect. I replaced the trackbar, both tie rod ends, and the tie rod and drag link itself. It was better, but I still had a shimmy from 43-50mph. The day I went to Brand new 33’s, everything was perfect.
 
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SecondChanceTJ said:
What specifically about the tires could be the issue? Bad wear pattern? And what about the track bar or tie rod ends? Loose connections?
Click to expand...
After the tire rotation did you balance the front two wheels? Wheels need to be perfectly balanced.Like others have stated the tires can be out of balanced as well.
Have you done a dry steer test? You might as well check the wheel bearings.
To answer your question a dropped pitman arm cannot prevent death wobble.
 
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06TJ35's said:
After the tire rotation did you balance the front two wheels? Wheels need to be perfectly balanced.Like others have stated the tires can be out of balanced as well.
Have you done a dry steer test? You might as well check the wheel bearings.
To answer your question a dropped pitman arm cannot prevent death wobble.
Click to expand...
Now that I think about it, I think one of the rear tires was a bit out of balance before I rotated. However the DW also started happening before the rotation. I’ll definitely look into getting them balanced.
 
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SecondChanceTJ said:
Now that I think about it, I think one of the rear tires was a bit out of balance before I rotated. However the DW also started happening before the rotation. I’ll definitely look into getting them balanced.
Click to expand...
Tires have to be spot on.... everything up front has to be reasonably tight .. bushings can't be soft , no slop in connections...it's a rare deal to see it if those things are all good.

Here's one...I hit 2"+ deep water at an intersection and got it once...how? Water got in my beadlocks and it set it off before it could distribute the water.

Also got it from a sticky caliper once.

Those are freaky things. Not what you have going on .

Are TJs prone to it? Not terribly when you consider there were almost a million made. Big ,thick tires increase the chance of imbalance (proportionally speaking. A stock tire out 1 percent isn't near as much weight as a 12.5 x 35 out 1 percent) Lifts also stretch the suspension limits and create wear stock TJ's don't see.

TJ's simply get it because they are coil spring track bar design...and all coil spring track bar designed vehicles deal with it.

I do think large tires are not in scale with the linkage and other components and tend to overwork things ..this has been debated but seems logical in my small mind, and why I think heavy duty steering components are beneficial for more than just surviving trail obstacles.
 
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AndyG said:
2. Passive Death Wobble
Click to expand...
You are creative, I'll give you that. Is that like micro vibrations that the MC bushings eliminate and micro aggressions we all exhibit towards the disenfranchised?

Or is it more like Jumbo Shrimp? Wait, wait, I got it, it's like the track bar lever arm, right?
 
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