Cough death wobble, cough. 2021 overland 13k miles

[Pcasp3]

Im interested in what you find after following the suggestions so far. Im willing to be that it has to do with the lift, or caster/toe.

Toe is VERY easy to check and reset your self. After doing it once I wont pay anyone to do it again.

as for the lift. I remember early on a mess of shops, and DIYers, were not replacing the front spring upper isolators correctly and that was causing the springs to bow. MAYBE it has to do with something like that.

Dealer installed everything. All alignment values within spec

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[Pcasp3]

Yeah, did they check and torque the ball joints?

Anyway, there's a lot of missing info here, sort of a mix of things -
What tires?
Did you change wheels?
Are you running wheel spacers?

The bit about the control arm brackets makes no sense, IMO. Brackets returning the control arms to parallel to the ground should have no impact on "bump steer" or "double-rebound" over small bumps. That makes no sense.

Was the axle re-centered after the lift?
I know folks will say it's not necessary but mine was lifted only a bit over 1" and the axle was definitely off-center and that can change the geometry.
Bump steer shouldn't have any relationship to the control arms.

Running stock wheels.
Tested with zero mile wheels and tires
Bump steer happened after dealer installed control arm drop brackets which induces too much caster

 

[White Betty]

I'm putting my money on caster. Try around 4.5° to 5°, that eliminated mine.

 

[Lunentucker]

Running stock wheels.
Tested with zero mile wheels and tires
Bump steer happened after dealer installed control arm drop brackets which induces too much caster

"Too much" to them is just enough for most of us.
It shouldn't need geo brackets on a pure stock setup though.

This was one of several things you cited that make me think they're idiots.

 

[LostWoods]

I would have to disagree. Both of those things are key components in solving death wobble. Tires and introducing a lift (granted a MOPAR lift isn't high) but a steering stabilizer is one of the key components in stopping it. Its not a "band-aid" its a legit part. One of the main reasons its there. Now its a very opinionated subject, but its one of the first things someone should look at esp considering that almost all installers of lifts and tires do mount and balancing plus an alignment.

I can assure you they're not. All those two will do is exaggerate existing problems. I did a lot of work on Jeeps in particular when I turned wrenches for a living and not once did either of those things cause a death wobble, no matter how much a customer insisted.

The steering stabilizer is a legitimate part that hides real issues. A vehicle should be stable without a stabilizer, all it does is serve to firm up the steering and reduce the impact of bump steer but here should not be oscillations, wobble, or wandering without one. You can use a heavy stabilizer to stop a death wobble problem but all that is doing is adding a damper to your death wobble, it's not fixing the defect that causes it.

 

[guarnibl]

Could be Ball joints

 

[Gren71]

Dealer installed everything. All alignment values within spec

Just because the dealer installed it doesn’t mean they did it right. Its your rig but double checking costs you nothing but a little time.

As far as within spec…personal experience speaking i had my JT “aligned” and was supposedly in spec. Even had the sheet that showed it. But when i checked my self my toe was equal on the front and rear of the front tires. Once i set it my self the JT drove WAY better and my death wobble went away.

 

[Jteakus]

All the good folks here can do are suggest places to look for slack. If you can't find the source I would suggest taking it to a quality alignment shop or a local 4x4 shop that has seen and dealt with DW before. Need some hands on from experienced eyes.

 

[Pcasp3]

I'm putting my money on caster. Try around 4.5° to 5°, that eliminated mine.

It is.

 

[Riccochet]

I would take it to a reputable 4x4 shop for a full shake down and alignment check.

 

[Pcasp3]

"Too much" to them is just enough for most of us.
It shouldn't need geo brackets on a pure stock setup though.

This was one of several things you cited that make me think they're idiots.

Complete fn idiots. Their manager tried to bully me into accepting their fix because allegedly I didn’t say it wasn’t 100% stock it has the mopar lift and I cussed this mofo out on the phone for 45 minutes saying it’s got a factory part number installed by a factory approved “trained” technician so yeah it’s “stock” basically told him my prior history with vehicles “used to work on multiple high end cars in; nascar, Ferrari challenge, Porsche GT3 cup, ALMS, Grand Am and quoted directly from jeep and this dumbass was like well we have high success rate with this bracket…. And I lost it like it does not belong on that kit.

 

[Lunentucker]

Complete fn idiots. Their manager tried to bully me into accepting their fix because allegedly I didn’t say it wasn’t 100% stock it has the mopar lift and I cussed this mofo out on the phone for 45 minutes saying it’s got a factory part number installed by a factory approved “trained” technician so yeah it’s “stock” basically told him my prior history with vehicles “used to work on multiple high end cars in; nascar, Ferrari challenge, Porsche GT3 cup, ALMS, Grand Am and quoted directly from jeep and this dumbass was like well we have high success rate with this bracket…. And I lost it like it does not belong on that kit.

Did you install the Mopar longer control arms? Those should have corrected the caster after the lift.

A positive caster of 5.5 - 6.0 drives great on these things.

 

[Riccochet]

A Mopar lift is not stock. You cussed a guy out because they want to further modify your already modified vehicle to correct the geometry? Real classy.

It is not stock. Where the lift kit came from, part numbers, who installed it, is inconsequential. It's modified from it's original configuration.

Those Mopar lifts are trash. They do nothing to correct the geometry. I would take that crap off and buy a real lift with adjustable control arms, front track bar and at least a rear track bar correction bracket. Get all of the geometry back in spec.

 

[ShadowsPapa]

Tires and introducing a lift (granted a MOPAR lift isn't high) but a steering stabilizer is one of the key components in stopping it. Its not a "band-aid" its a legit part.

Naw, it's not....... I've posted over and over quotes from real legit suspension design engineers, performance engineers, and guys who design this stuff - one of them worked for MOPAR for years.
This quote is from a guy who modified Power Wagons and Jeeps for years, owned and operated businesses that were involved in just that. He was a desert racer in the 1960s and NASCAR pit crewman in the 1970s ->

A steering damper is not a fix, it's a band-aid used to mask issues with either worn components or poor design. Dampers did not start appearing on stock vehicles until the late 70s, mostly associated with the trend to larger (wider thus heavier) tires on older designs. Rather than redesign the entire front-end geometry, AMC found it less expensive to add the damper.

On a properly designed and well maintained system, a damper's purpose is to mitigate the effects of bump steer and the sudden encounter of unexpected objects, such as hitting a rock in a trail at 50 miles per hour. On an improperly designed and/or poorly maintained system, a damper is used as a crutch to mask issues with suspension and tire errors.

Jeeps and other vehicles experienced shimmy way before the 1960s, and before the advent of lifts and larger tires. Worn components are just as much at fault as jury-rigged suspensions.

A Jeep engineer was involved in that discussion and never even suggested that a dampener was a fix or solution. His experience is listed below -

• Freightliner engineering, 2008-09
• Senior engineer - chassis design synthesis (developed business integration plan, process, and documentation for CATIA use in advanced vehicle engineering), 2002-2004
• CATIA Kinematic Application trainer and engineer, American Axle, 2002
• Tenneco Automotive Japan, Ltd - Consultant on exhaust systems design and prototype troubleshooting to Isuzu on GMT 355 / ISZ 190 project; employee training on design systems, 2000-01; Vehicle Exhaust Systems Design and Prototype Troubleshooting to Isuzu Motors, Fujisawa, Japan on GMT 355/ISZ 190 Project
• Tenneco Automotive, Michigan, American LaFrance design, Wagner Lighting (exterior lighting systems for GM and Chrysler), Catnet, Autoliv (airbags/restraings for GM and Chrysler), Masland (interior components for Chrysler), GM Corvette Group (C5 mule prototype design), Harvard Industries (engine fans for GM, door frames for Chrysler)
• Chrysler Corporation Jeep/Truck Engineering, 1987-1992, including Senior Designer, 4x4 Vehicle Suspensions - responsible for all 4x4 suspension design concepts on Dodge BR (full size RAM pickup); Jeep Motorsports race team assistance.
• AM General - senior suspension design for FMTV and HMMWV; GM Truck Group - Military Vehicles Operations; GM Truck and Bus Group, International Harvester TSPC and Scout Group

But everyone on the internet is an engineer, so I guess that guy was full of crap, eh?
If everything is fine, you can take the damned dampener off and drive it fine.

 

[ShadowsPapa]

Running stock wheels.
Tested with zero mile wheels and tires
Bump steer happened after dealer installed control arm drop brackets which induces too much caster

Yeah, too much caster is a problem. People seem to think "gee, a little bit helped my wander, I'll give it more" and then they introduce other issues.
I see people talking about 6 degree caster - that's the bleeding edge of trouble.
Mine was lifted about 1.25" and the caster was under 5 and it tracked and handled like a dream. It didn't wander, on a flat road without wind you could let go of the wheel for a long ways and it would keep between the lines. No way I'd have ever put more than 5 degrees caster on that truck.

Toe can impact handling, and too much caster combined with incorrect toe (for YOUR vehicle) can cause poor handling and actually in that case, caster can contribute to tire wear. Caster is generally not associated with tire wear, but if it's too far and other settings are wrong as well, the combination does wear tires.

A positive caster of 5.5 - 6.0 drives great on these things.

That's a blanket statement that doesn't work for all.
Each lift, each set of conditions will mean different settings will be "best" for "that truck". I've done alignments for decades - and one reason there are ranges in specs is because conditions can vary - tires, tire sizes, a lot of things enter into it.
6 is bleeding edge and can introduce instability.

Yesterday I mentioned "caster wobble"- well, the guys who believe "more caster is better" may be causing their own death wobble. Again, I've done alignments since before IBM even made a PC, before there was an alignment computer.

Gee, does THAT sound familiar???

Too much caster can lead to loss of traction for steering and braking around curves and corners, too. I was going to write it up, I have all the info in my college books, but I ran across a Ford guy who agreed with my college texts (I spent a college quarter in alignment)

Interesting how people never consider other angles and things to check. it's always the only things talked about "around the internet", and never how things work in association with each other, or how changing one thing will have a negative impact on other aspects of performance.
Change one thing too far and in an emergency you are shouting "oh, sh!!" at the top of your lungs. In 30,000 miles you are wondering why you have to replace tires or suspension parts..........

One big take-away from my studies of solid or straight axle vehicles with a lift is that you introduce forces that weren't there before. One of the biggies is how the track bar and drag link actually flex and how they act like springs - and can cause shimmy or wobble.

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