DO I NEED A STEERING STABILIZER?

[Deleted User 38384]

I used to be in the "no steering stabilizer required" camp, because nobody could explain why it was necessary on some vehicles but not others. It always seemed like a band-aid for poor design and/or worn parts.

But after a few years I have a theory... which I'm sure many will disagree with: Larger profile tires act like a spring more than lower profiles. This springy-ness happens up/down in the direction of the suspension, and also side-to-side. Some of this motion is absorbed by the bushings and/or tires, but some is transferred to the steering linkage. This is what the steering stabilizer is trying to dampen... the tire oscillation, not the suspension/steering.


Edit: this kind of tire movement, but imagen a larger profile tire.

Works for me. That's kind of what I was thinking myself. That the larger tire size acts as a cushion itself. I do think when I was running my 32-in 10 ply tires I probably would have noticed it a lot more. But with these 37 load D-range tires, I just don't notice it.

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[AnnDee4444]

Works for me. That's kind of what I was thinking myself. That the larger tire size acts as a cushion itself. I do think when I was running my 32-in 10 ply tires I probably would have noticed it a lot more. But with these 37 load D-range tires, I just don't notice it.

A stiffer sidewall shouldn't deflect as much, meaning the need for a stabilizer should be less (if my theory is correct). This should also be true for higher tire pressures, wider wheel widths, and of course lower profiles.

Another random thought I had was that higher caster could actually make the tire's oscillating mass have a greater effect on the steering. This is easiest to visualize if you consider that zero degrees of caster would result in no steering change when loaded side-to-side. Increase the caster and it increases the lever arm effect between the lead point & wheel contact point in the diagram below.

 

[AnnDee4444]

The steering stabilizer is there to mitigate the side to side forces and oscillations. It is an integrar part of the steering design on a SFA vehicle, just like shock absorbers are an integral part of the suspension design.

I can't find a good argument of why having a solid axle matters. I've seen hot rod style roadsters with straight front axles doing autocross... no steering stabilizers. Some sprint cars have solid front axles with no steering stabilizers, and they do all sorts of weird things like making one of their rear diff links a shock.

I'm really starting to think that the steering dampener is there to dampen the uncontrolled mass of the tire. There really isn't a good term for this either... like the difference between unsprung and sprung mass. There's the portion of tire that moves with the suspension (at the bead of the wheel), and the mass of tire that flops around like a balloon.

 

[Deleted User 38384]

Go ahead, you can talk all the shit you want I know I have it coming!

Spoiler: :swear:

 

[gato]

I've seen hot rod style roadsters with straight front axles doing autocross... no steering stabilizers. Some sprint cars have solid front axles with no steering stabilizers, and they do all sorts of weird things like making one of their rear diff links a shock.

And most go carts don't have shock absorbers, or a suspension. These are light specialty machines designed to run on prepared surfaces, with no pot holes, on tiny/light tires.

They have no comparison to a heavy solid axle vehicle that will be hitting pot holes with heavy tire/wheels.

It's just physics. Once a solid front axle wheel hits a bump and goes up the steering linkage has to be pushed to the side. With high speeds, heavy wheels and a big enough bump, those forces are massive. That is why you need a shock absorber there a.k.a. steering stabilizer.

 

[Ratbert]

Go ahead, you can talk all the shit you want I know I have it coming!

Spoiler: :swear:

We appreciate you risking your life in the name of science!

 

[AskBin]

I worked at some Ford dealers during the f250 death wobble epidemic, and Ive had a 16' 2500 silverado with like 1000lbs of glass it was hauling start to death wobble on me.

Even if a steering damper is just a band aid for worn out parts, Ill personally keep that bandaid on lol. Just reducing the possibility of death wobble is enough to warrant deeming it necessary.

 

[Roky]

If DW can’t get started then it can’t happen… The SS is designed to reduce steering wheel vibrations. If you have worn bushings, or loose connections DW will still happen with or without it…. Being that OP got DW without SS on warrants a check of the steering linkages, starting with the track bar… If he puts the SS back on and the same spot doesn’t cause DW that means parts aren’t worn or loose enough to fight past the stabilizer but rest assured, it’s coming…..

 

[Flip]

If DW can’t get started then it can’t happen… The SS is designed to reduce steering wheel vibrations. If you have worn bushings, or loose connections DW will still happen with or without it…. Being that OP got DW without SS on warrants a check of the steering linkages, starting with the track bar… If he puts the SS back on and the same spot doesn’t cause DW that means parts aren’t worn or loose enough to fight past the stabilizer but rest assured, it’s coming…..

Roky,

I've been meaning to ask this question for awhile now. In your opinion, do wide tires contribute to death wobble?

 

[Roky]

Roky,

I've been meaning to ask this question for awhile now. In your opinion, do wide tires contribute to death wobble?

I don’t know the science if it does or not, but in my experience, I haven’t noticed any difference in tire width having more or less affect on DW….I’ve fixed it on all different tire sizes on jeeps and trucks…..

 

[AnnDee4444]

These are light specialty machines designed to run on prepared surfaces, with no pot holes, on tiny/light tires.

They have no comparison to a heavy solid axle vehicle that will be hitting pot holes with heavy tire/wheels.

Tire weight is usually somewhat related to profile.

Once a solid front axle wheel hits a bump and goes up the steering linkage has to be pushed to the side.

Double A-arm & Macpherson also do this. Unless the suspension design has bump steer built in, there should be no steering happening during a bump, and nothing to dampen. Sure the axle moves sideways, but so does the damper/drag link/track bar.

Also I feel like there is a term missing that differentiates "bump steer". There's two ways I've seen people using it: # 1 steering that happens when the suspension is cycled (at any speed) that is dictated by the suspension/links, and # 2 I hit a bump and lost control of the steering. When I reference bump steer I'm referring to # 1 above.

FWIW: I'm even aware of a steering stabilizer on a double A-arm car (Mercedes R107) which coincidentally has taller profile tires (205/70 R14). There's not a lot of tire mass, but what is there is pretty far away from the wheel and free to spring back & forth. Another example has double trailing arms (Early VW/Porsche) and also taller profile tires.

 

[AnnDee4444]

Roky,

I've been meaning to ask this question for awhile now. In your opinion, do wide tires contribute to death wobble?

You might find this interesting, even though I had guessed completely wrong: https://www.jlwranglerforums.com/forum/threads/death-wobble-poll.29145/

37% of Sports (245/75R17) had death wobble, but only 16% of Rubicons (285/70R17). Same wheel specs. One tire has a taller profile and probably less stiff sidewall, and even though it is shorter and lighter still has 2.3x the instances of death wobble reported.

The Sahara is the worst (46%) despite having a lower profile than the Sport (255/70R18). With only 0.6" taller diameter, I have no idea why...

 

[AnnDee4444]

I've got it now. The axles are basically shake weights.

 

[Ratbert]

Roky,

I've been meaning to ask this question for awhile now. In your opinion, do wide tires contribute to death wobble?

It's almost as if someone is looking for a way to justify their decision to go with skinny tires.

 

[Flip]

It's almost as if someone is looking for a way to justify their decision to go with skinny tires.

@Roky

On the contrary. I was asking because I might go to a larger/wider tire in the future.

This brings me to my 2nd question. When running larger/wider tires on a stock jeep, do they contribute to wearing out parts & components?

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