Is this bump steer or something else?

[Yondu_JLU]

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.

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[dstevens]

What is your castor?

For general Jeep front suspension problems I get someone to work the steering wheel vigorously back and forward with the engine off. Then I work my way through the tie rod ends, drag link ball joints, track bar mounts, pitman arm etc using a finger across the two components. If there is any play you can feel the moment between the parts. It picks up most problems readily. In your case I'd check the steering box and linkage as well.

 

[Yondu_JLU]

What is your castor?

For general Jeep front suspension problems I get someone to work the steering wheel vigorously back and forward with the engine off. Then I work my way through the tie rod ends, drag link ball joints, track bar mounts, pitman arm etc using a finger across the two components. If there is any play you can feel the moment between the parts. It picks up most problems readily. In your case I'd check the steering box and linkage as well.

Steering box and linkage are brand new, installed within the past few months. Castor was supposedly cranked up to about 5 or 6 degrees from 3 degrees but I am not sure exactly where it sits now.

 

[Hucke_250]

Do you know the weight of your wheels and tires? If not can you post the make, size and load range of your tires as well as the wheels?

 

[Yondu_JLU]

Dirty Life DT-1’s, gunmetal grey 5x127 -12mm offset. Nitto Trail Grappler 35x12.50r17 Load Rating E
Roughly 124 pounds per corner I’d guess?

 

[Yondu_JLU]

Dirty Life DT-1’s, gunmetal grey 5x127 -12mm offset. Nitto Trail Grappler 35x12.50r17 Load Rating E
Roughly 124 pounds per corner I’d guess?

@Hucke_250

 

[dstevens]

Steering box and linkage are brand new, installed within the past few months. Castor was supposedly cranked up to about 5 or 6 degrees from 3 degrees but I am not sure exactly where it sits now.

Well nothing should be wrong but something is wrong, so you'll need to do some detective work. As far as the castor goes I'd verify what it actually is. You can use an angle finder on the case spreading holes of the front diff, which should be 6 degrees different from the ball joints on the knuckle. If you have strong self centering when cornering then it probably is not castor, but it has to be eliminated as the cause.

 

[Hucke_250]

Dirty Life DT-1’s, gunmetal grey 5x127 -12mm offset. Nitto Trail Grappler 35x12.50r17 Load Rating E
Roughly 124 pounds per corner I’d guess?

I found in a thread that the Dirty life DR-1’s are supposedly 50lbs with the bead lock installed and the tires are listed as 80lbs.

I too dealt with a lot of bump steer even though I had upgraded all of my steering components and my caster was dialed in at 6.5. I ended up selling my heavy 20x9 Fuel wheels and 35x12.5x20 load E tires (109lbs). I switched to 315x70x17 load c and 17x8.5 KMC wheels (88lbs). My bump steer is virtually gone except for the largest of bumps.

I suggest you get your alignment checked and post the printout here. Id like to see what your castor and toe is. I would also swap out wheels and tires with a fellow Jeeper and see if the lighter wheel and tire setup lessens the bump steer.

 

[Old Jeeper]

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.

That is (most likley) NOT bump steer. Bump steer is when the steering wheel is not centered and you hit a bump and the steering wheel jerks left or right and does not return to center. You can check to see if the pitman arm is centered and at the same time the steering wheel is centered.

What you are seeing are the EARLY stages of DW. It starts out with a little jiggle and progresses from there. TAKE ACTION IMMEDIATELY if not sooner. To start, replace your SS with an HD unit and see if that makes a difference at all. Check your caster and have you changed tires and added any suspension mods.

 

[chadk77]

Dirty Life DT-1’s, gunmetal grey 5x127 -12mm offset. Nitto Trail Grappler 35x12.50r17 Load Rating E
Roughly 124 pounds per corner I’d guess?

Are you running Hubcentric rings with those wheels??

I bought a set of 71.5 to 78.1 rings off Amazon for $20 and they made a huge difference in how my Jeep drives. May not be the solution to this issue but I'd say it would help as it did with mine. It brakes smoother, accelerates smoother, and rides a lot smoother.

 

[Yondu_JLU]

That is (most likley) NOT bump steer. Bump steer is when the steering wheel is not centered and you hit a bump and the steering wheel jerks left or right and does not return to center. You can check to see if the pitman arm is centered and at the same time the steering wheel is centered.

What you are seeing are the EARLY stages of DW. It starts out with a little jiggle and progresses from there. TAKE ACTION IMMEDIATELY if not sooner. To start, replace your SS with an HD unit and see if that makes a difference at all. Check your caster and have you changed tires and added any suspension mods.

It has a Fox 2.0 TS stabilizer, has not really helped. Have removed the stabilizer before and issue was still there.

 

[Yondu_JLU]

Are you running Hubcentric rings with those wheels??

I bought a set of 71.5 to 78.1 rings off Amazon for $20 and they made a huge difference in how my Jeep drives. May not be the solution to this issue but I'd say it would help as it did with mine. It brakes smoother, accelerates smoother, and rides a lot smoother.

I had bought a set wayyyy back when I bought the wheels but I think they were tossed by a shop or not installed at one point or another because I don’t have them on the Jeep right now. Bought another set and will be installing this weekend hopefully.

 

[Old Jeeper]

It has a Fox 2.0 TS stabilizer, has not really helped. Have removed the stabilizer before and issue was still there.

Looking at the video many times and don't know what kind of a road you are on. But what see I more Jeep normal than anything else. There is a stretch of road, not far from my home that is paved and my steering wheel does the same thing as you on that one stretch of about ¼ mi. My question is: Does it always jiggle like this your video?

 

[silverooby]

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.

Track bar brace fixed my wobble, although it was more wobble than in your video clips. My setup is similar to yours.

 

[JT1]

Track bar brace fixed my wobble, although it was more wobble than in your video clips. My setup is similar to yours.

That's a really good point. Track bar brace deflection is a thing when you get above 3" of actual lift.

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