Is this bump steer or something else?

[Rodeoflyer]

He added a brace... it's a lightweight vehicle on 800lbs of wheels tires..

some new axles would probably be the fix.

Did you do the steering box recall?

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[Roky]

Trying to get to the bottom of this -- it feels like I have replaced every component on the front end of my Jeep at least once if not twice to no avail. 2020 JLU, 35s and bead locks. Full Synergy steering and control arms, new steering box and brace, Reid racing knuckles and dynatrac balljoints, fox ts stabilizer. 2-3 Inch Synergy lift (advertised), shocks are for 3.5-4" per Synergy recs, no flip kit, drag link and track bar angle via a level are both about 7 degrees -- not sure if that plays a role in this.

The problem I am and have been encountering is a steering wheel jiggle that occurs over bridge seams, humps in the road, pavement dips, potholes, rough roads, etc. The jiggle ranges from mild to shaking back and forth over rough roads to full on pulling the vehicle in a direction if it hits large enough of a dip -- best way of explaining it is that it feels like there is no resistance in the steering, i.e. my arm and hand act as the stabilizer lol, and any imperfections in the road become jarring as a result. It still returns to center, turns fine. I do not suspect this is a wheel and tire issue as there is steering feedback associated with it and not just a vibration, and the Jeep becomes difficult to keep straight if it "jumps". It does not feel like death wobble either as it is not a persistent oscillation most of the time. What I am seeking is for the wheel to feel STABLE -- it should not be loose and prone to moving on its own over imperfections.

I'm running out of ideas as to what this could be -- maybe my shocks are too long and causing instability? drag link/track bar angles too steep and needing a flip kit? wheel and tire weight/ stress on the hubs? intermediate shaft? Any advice would be appreciated.

Does your Jeep try and change direction when the wiggle occurs, doesn’t appear to in the vid. if not, it’s not bumpsteer……. That small wiggle in your vid is exactly what the steering stabilizer was designed for….. it looks like your heavy wheel/tires are over powering it…. Is your stabilizer adjustable, if so crank it up a few clicks…. I have the same brand wheels /tires as you and I need to run my Fox ss at 17 clicks to make it happy, or I run the EC stabilizer….., here’s my steering wheel on a potholed gravel road at 37 miles an hour. I put a toolbox in so you can hear when I hit the rough spots because the steering wheel doesn’t move……my hand does holding the camera…….?

 

[Rodeoflyer]

Yep, just a jeep thing.. they should have put a d60 in the new JL and worked into the ridiculous price

 

[Yondu_JLU]

He added a brace... it's a lightweight vehicle on 800lbs of wheels tires..

some new axles would probably be the fix.

Did you do the steering box recall?

Yeah it’s got the new box

 

[Yondu_JLU]

Does your Jeep try and change direction when the wiggle occurs, doesn’t appear to in the vid. if not, it’s not bumpsteer……. That small wiggle in your vid is exactly what the steering stabilizer was designed for….. it looks like your heavy wheel/tires are over powering it…. Is your stabilizer adjustable, if so crank it up a few clicks…. I have the same brand wheels /tires as you and I need to run my Fox ss at 17 clicks to make it happy, or I run the EC stabilizer….., here’s my steering wheel on a potholed gravel road at 37 miles an hour. I put a toolbox in so you can hear when I hit the rough spots because the steering wheel doesn’t move……my hand does holding the camera…….?

I think more so indirectly, the wheel becomes so hard to keep straight sometimes that the Jeep tends to move to one side or another. Sometimes over a dip at low speeds the wheel will turn in the direction of the dip/ side of the vehicle it is on. Always seems to return to center after though, it does not stay turned to one side for a prolonged time.

 

[Roky]

I think more so indirectly, the wheel becomes so hard to keep straight sometimes that the Jeep tends to move to one side or another. Sometimes over a dip at low speeds the wheel will turn in the direction of the dip/ side of the vehicle it is on. Always seems to return to center after though, it does not stay turned to one side for a prolonged time.

I’d like to see you increase your caster to 6 also, that will help too…..

 

[Rodeoflyer]

I'm at 7deg caster and still get this with 37's. It's a sensitivity thing unless you truss the front.

 

[Yondu_JLU]

So I guess I’ll start with a good alignment — I’ll try to install the hub rings this weekend too and get the tires rebalanced. Maybe lower the pressure too. Beyond that I’m not sure what it could be besides caster or the wheels not being squared due to the hub bore and putting stress on the axle.

I’d like to see you increase your caster to 6 also, that will help too…..

 

[AnnDee4444]

As stated earlier, this is not bump steer. This is caused by uncontrolled movement between the track bar & drag link. For example: one turn of the track bar adjuster changes the steering wheel straightness significantly... and the track bar only got ~1/16" longer (not sure of the actual thread pitch). It takes a tiny difference between the two links to create noticeable steering difference. The bump turns this into an oscillation while the stabilizer does it's best to slow it down. If the stabilizer fails to slow the oscillation, death-wobble is the result. A stiffer stabilizer will slow these oscillations better, but I believe the weak track bar mount is what allows them to start. Changing caster and/or tire pressure is just tuning the oscillation to a different frequency, possibly outside the parameters of typical driving.

Assuming the bushings are good and steering box is adjusted, I would try a different track bar brace first. In my opinion the Metalcloak track bar brace appears to be the strongest option, since it adds two extra bolts in a separate plane (replace the Synergy brace). When I installed it on my stock JLR I didn't use the bottom two bolts at first... and could definitely tell a difference when it was fully installed. Now I'm considering removing the stabilizer completely.

Also it would be interesting to try the Synergy brace with & without the sector shaft brace to really see how much of a difference it makes.

Track bar brace deflection is a thing when you get above 3" of actual lift.

It's a thing on stock a Rubicon.

It's a sensitivity thing unless you truss the front.

How would trussing the front help?

 

[Rodeoflyer]

Trussing the front axle makes everything stiffer, so you get less flex when you put 150lbs of tire/wheels on the outside of the axles.. makes sense?

Actually 300+ lbs, plus the vehicle weight, which is pretty extreme with the JLUR and 8.5/6'' axles

 

[AnnDee4444]

Trussing the front axle makes everything stiffer, so you get less flex when you put 150lbs of tire/wheels on the outside of the axles.. makes sense?

Yes, but the axle location & steering is still controlled by the drag link & track bar.

I highly doubt the axle housing is flexing enough to cause that amount of difference in the steering, and if it was it would need to oscillate back & forth a few times per second.

 

[Rodeoflyer]

No it does flex that much, unless you truss it

 

[Roky]

Assuming the bushings are good and steering box is adjusted, I would try a different track bar brace first.

I’m not buying into this, there’s way to many rigs out there that I know of and heard of that are using synergy and yeti tb braces and have absolutely no wiggle at all, including myself……I would suspect the synergy track bar however, back in the day they had some trouble with the pinch bolt not tightening enough, they’ve probably fixed that by now, but I’d check it out just to eliminate the possibility…….

 

[AnnDee4444]

I’m not buying into this, there’s way to many rigs out there that I know of and heard of that are using synergy and yeti tb braces and have absolutely no wiggle at all, including myself……I would suspect the synergy track bar however, back in the day they had some trouble with the pinch bolt not tightening enough, they’ve probably fixed that by now, but I’d check it out just to eliminate the possibility…….

I tried the Metalcloak brace with the bolts in just the locations that other braces have (well, minus the 4th steering box hole). Adding two other bolts in a separate plane made it go from barely noticeable to "I don't think I need a steering stabilizer anymore".

The sector shaft brace always seemed a bit odd to me. I'm skeptical that it needs bracing. I do own a Metalcloak sector shaft brace, but can't install it with the amount of bump stop I'm running (needs 2" min., I have 1").

 

[Roky]

I tried the Metalcloak brace with the bolts in just the locations that other braces have (well, minus the 4th steering box hole). Adding two other bolts in a separate plane made it go from barely noticeable to "I don't think I need a steering stabilizer anymore".

The sector shaft brace always seemed a bit odd to me. I'm skeptical that it needs bracing. I do own a Metalcloak sector shaft brace, but can't install it with the amount of bump stop I'm running (needs 2" min., I have 1").

Understood…….all of these rigs are a bit different even though they are supposed to be “cookie cutter”…… I think that’s why different parts sometimes cure the same problem on different Jeeps….. Maybe when you lift and run tons and 4Ds you can run the rest of your brace, lol…

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