Installed Clayton Lift, now have steering wheel shimmy.

[OM Jeep]

Alright, bear with me as I know there are tons of shimmy/wobble threads out there but I think this may be a slightly unique situation.

I have a 2020 Gladiator Rubicon with 31,500 miles.

The symptom is a steering wheel shimmy while hitting certain bumps/potholes at 30-50 mph. It looks very much like this, maybe slightly less intense:

So, not a death wobble but still undesirable.

Suspension related upgrades before the shimmy started:
-Teraflex leveling kit
-37” A/T tires
-Fully stock Rubicon components

Upgrades after which the shimmy began:
-Full Clayton Overland Plus 3.5” lift (used with about 10,000 miles total)
-Fox IPS 2.0 shocks (10,000 miles)
-Yeti XD drag link (10,000 miles)
-Everything installed by a local, well respected, and recommended 25+ year mechanic and Jeep enthusiast.

Things I have added/done since the shimmy began, which has seemingly helped a bit:
-Alignment and rotation
-Fox ATS Steering Stabilizer

My thoughts as I think through what could be causing this:
-My caster is at 7.0. Is this too high?
-Could either the Clayton front track bar or Yeti drag link bushings be going bad at 10,000 miles?
-I don’t think it’s the ball joints since everything was fine before the lift. Right?

I don’t really want to keep throwing money at this issue as that’s a slippery slope.

The mechanic said to come by and I will likely take him up on that, but he’s an hour away and that likely won’t happen until next week at the earliest.

Would love any thoughts here, even if just brainstorming.

Thanks guys!

Sponsored

 

[NewGladdyOWNR]

Things I would start with: Measure track bar to match Clayton's measurements, check torque on all suspension components. Clayton recommends 5-6 degrees caster. I cannot imagine 7 degrees would cause your issue. More than likely trackbar and/or drag link issues. Good luck!

 

[Wheelin98TJ]

I'd start with a dry steering test paying close attention to the track bar and control arms since those were some of the last things touched before this started.

Also, since the shimmy is not quite full on death wobble, I'd suspect tire balance could be off. You could try rotating the tires to see if it changes.

 

[Free2roam]

I had a wobble shimmy after about 7k miles. What is the tire rim combo? Are you wider than stock? @ShadowsPapa can tell you about scrub radius.
I eventually ended up going 2.5 ton Fusion 4x4 steering upgrade. With Fox ATS stabilizer. Issue solved. Even the wife noticed it. My rims are -6 Icon Rebound Pros.
My thoughts on it were when going wider it's putting more stress on the stock components which can't handle it. The longer the arm the more force/torque you apply on the stock components.

 

[Gizmo]

I took a degree of caster out of mine and got rid of what felt like a tire balance issue at 65-70 mph . Im at 6* and very happy. Lowering the caster to 6 gave a more precise feel to the steering where to much caster made the truck track good but steering feel had kind of a vague feel almost like the steering box had a hair play in it when going straight plus 6 is easier on ball joints and steering correction requires less movement

 

[ShadowsPapa]

Things I would start with: Measure track bar to match Clayton's measurements, check torque on all suspension components. Clayton recommends 5-6 degrees caster. I cannot imagine 7 degrees would cause your issue. More than likely trackbar and/or drag link issues. Good luck!

5 to 6, I'd not go over 6.5 and yes, too much caster can indeed cause "caster wobble". Ask some Harley riders among others.

My thoughts on it were when going wider it's putting more stress on the stock components which can't handle it. The longer the arm the more force/torque you apply on the stock components.

Absolutely - tie rod, drag link, all have a lot more force on them because the wider you make your stance - the farther out the center of that wheel is from the line through the ball joints, the more force there is to drag that wheel BACK. What happens is that one wheel wants to drag back, loading up like a spring, then it unwinds and the other wheel drags back until it can't overcome the force of the other wheel, and it goes back and forth. There's a reason factory vehicles don't have wheels sticking out like the butt end of a bull frog. It may look cool to some, but it's a horrible load on things and opens you up for things you don't think about while trying to make it look cool (to you)

You run into similar for scrub radius - it involved an imaginary line straight through the steering axis, or the center of the ball joints (king pin if it had one) compared to the line down through the centerline of the tire. Where those meet - above or below the road, matters.

My take - if you don't require the wheels sticking out for purpose - don't do it.

 

[Dickster]

Have a buddy come over, crawl under the jeep and have him saw on the wheel. Look for any loose parts or flex where there shouldn't be.

 

[adamjedgar]

Castor and change out the stock steering dampener.
Mines only got a 2" lift, 33x12.5s with wide rim offsets and its a real handful to keep straight at high speed sometimes. I'll be making some changes to mine for sure so I can only imagine what yours is like.

 

[ShadowsPapa]

and change out the stock steering dampener.

Again, that's a bandaid. The underlying issue that is the true cause of the shimmy will still be there. The shimmy will still be working on that steering dampener and will eventually wear it out as well - it will just take longer with a better one.
Those are not intended to take care of shimmy in any form, mild or severe.


For those who like the frog's butt look of tires sticking way out with those deep wheels, taller tires can help put the scrub radius back down a bit.

 

[Camaroboi13]

Castor and change out the stock steering dampener.

Things I have added/done since the shimmy began, which has seemingly helped a bit:

-Fox ATS Steering Stabilizer

 

[ShadowsPapa]

Again, here's the stuff from Norm Layton, known in the vintage Power Wagon and Jeep circles as a Jeep mod/suspension guru, and owner of 4540 Motorsports -

It is not a fix - the REAL causes still exist.

Again, from Norm Layton -

(he continues with adding "improper design" and so on - implying design changes like lifts and wheels/tires and so on. He also includes tires, wheels, shocks as potential causes)

And a suspension engineer, Bob Sheaves says -

A lift puts the trackbar and draglink out of level, putting them at an angle instead of straight across. That means the parts can flex or deflect. When you drop the axle compared to the steering gear - you put that link at a greater angle, allowing deflection out of plane.

The steering stabilizer, dampener, whatever you want to call it isn't a fix - it's a cover-up. The fix is to try to put things back into as close as possible to original geometry, or at least use heavier parts than stock.

Above is a brief hint on why I say tire sizes and wheel backset can cause these issues - especially with STOCK parts. That's from a suspension engineer. (in case you don't believe me, at least consider them)

Now if you want to continue to argue with Norm (sorry, he's dead, guess you can't) or Bob, and still say a "stabilizer is a fix" - here's Bob's experience, and I'd bet it trumps most people on Jeep forums -

 

[hjdca]

I have the same lift for over 50K miles now. No problem. In addition to what others have said, I added a RPM 2.5 ton tie rod and drag link. The steering and tracking tightened up tremendously. That together with a new steering stabilizer made a big difference in the feel of the front end. I felt a difference immediately, I mean it really, really tightened up .... I believe the tie rod makes more of a difference than the drag link, but, I am not sure. I know it is more money, but, with that kit and 37s, I believe the beefy joints on the big aftermarket tie rods and drag links are worth it. Note: I am running approx. 6.5 degree of caster.

 

[ShadowsPapa]

I know it is more money, but, with that kit and 37s, I believe the beefy joints on the big aftermarket tie rods and drag links are worth it.

Yup. When you throw those parts into an angle, it's better to have beefier "rods" connecting things.
Pretty simple to visualize really - take any flexible stick and try to push something with it - by pushing perfectly straight on the end. No problem - you are compressing it directly.
Now lift it up higher and try to push the heavy object - it's going to flex because the pressure isn't straight on. The more you lift, the more you put those things under a totally different loading. Look at the pole vaulter's pole - if they ran at a wall with that pole and hit straight on - they'd poke a hole in something, but approach it at an angle, the pole bends and then springs back.
That's the problem with stock parts and certain lifts and tire combos - those parts can flex and then spring back, oscillating, when there's more angle introduced.

It's an engineered system of parts that must work together. Once you make changes, you change the loading, and requirements on the parts. Time for some better than stock parts.

 

[Artsifrtsi]

You said rotating tires and helped...

Try getting the tires re-balanced, 90% (+/-) of the time wobbles are tire related that influence weak/worn out parts.

EDIT: Also, what pressure are you running?

 

[ShadowsPapa]

You said rotating tires and helped...

Try getting the tires re-balanced, 90% (+/-) of the time wobbles are tire related that influence weak/worn out parts.

EDIT: Also, what pressure are you running?

Whaddya think - road force balancing for the larger tires?
Feels right to me......

Sponsored