Cant figure out slight shimmy above 60 mph

[Waffen6]

So little background as I asked something about this before and still have the issue. 2022 Gladiator Rubicon, around April, (1500 miles on it) installed a skyjacker 3.5" dual rate kit that included new springs, adj track bar, longer lower control arms and shock brackets to reuse factory Fox shocks. Installed a set of new wheels and 37x12.5R17 BFG TKO C range tires. Tires all took 10+ oz with a couple taking over 15 oz. Was drivable but had the shimmy. First fix attempt after having them balanced a second time was balancing beads. Made it 10x worse and undrivable above 40 mph. Second attempt was a different set of wheels as first set did not allow for good weight placement. All tires now balanced out using 7oz or less except one that still took 17oz (but did balance). It ended up on the front and still had same shimmy. Called BFG they warrantied it out, new one balanced under 7oz. While in the air I finally rechecked the torque on all the suspension parts I installed and very embarrassed to say some were not even close, mainly the sway bar links and lower shock mounts. This didnt help either. Still have shimmy and jeep is at 3000 miles now, basically above 60 if I let go of the wheel I can watch it shake back and forth, if I hold the wheel you cant see it but can slightly feel it. I work at a dealer (non Chrysler) as a parts manager so lucky to have personal access to lifts and balancers whenever I need, but I cant find anything loose or wrong. Ive also checked the alignment twice (first after the lift and again here recently) Could I need an updated or better steering shock? Where should I go from here thanks!

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[OffAxis2021]

I will always feel that hub centric wheels are near the top of the “important” list, if not the most.

My AEV w/GCBs only lift, 35x10.5x17 on 8.5” wide 0 offset and 71.5 hub bore centric wheels drives as smooth as I feel it should and at speeds well above local limits.

I also run 255/85R17 (35x10x17) on base Mojave wheels in the winter and again… as smooth as I feel it should be.

I took a short video of me driving 85mph, but don’t know how to upload videos here.

I comment to see replies as well.

 

[Maximus Gladius]

So little background as I asked something about this before and still have the issue. 2022 Gladiator Rubicon, around April, (1500 miles on it) installed a skyjacker 3.5" dual rate kit that included new springs, adj track bar, longer lower control arms and shock brackets to reuse factory Fox shocks. Installed a set of new wheels and 37x12.5R17 BFG TKO C range tires. Tires all took 10+ oz with a couple taking over 15 oz. Was drivable but had the shimmy. First fix attempt after having them balanced a second time was balancing beads. Made it 10x worse and undrivable above 40 mph. Second attempt was a different set of wheels as first set did not allow for good weight placement. All tires now balanced out using 7oz or less except one that still took 17oz (but did balance). It ended up on the front and still had same shimmy. Called BFG they warrantied it out, new one balanced under 7oz. While in the air I finally rechecked the torque on all the suspension parts I installed and very embarrassed to say some were not even close, mainly the sway bar links and lower shock mounts. This didnt help either. Still have shimmy and jeep is at 3000 miles now, basically above 60 if I let go of the wheel I can watch it shake back and forth, if I hold the wheel you cant see it but can slightly feel it. I work at a dealer (non Chrysler) as a parts manager so lucky to have personal access to lifts and balancers whenever I need, but I cant find anything loose or wrong. Ive also checked the alignment twice (first after the lift and again here recently) Could I need an updated or better steering shock? Where should I go from here thanks!

Did you road force balance the tires?

 

[Lunentucker]

Did you check the torques on the ball joints, steering gearbox bolts and Pitman arm nut?
What "longer control arms" did you use? Mopar?
Try toeing out a tiny amount after insuring the above are torqued correctly.

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[Gizmo]

Usually at that speed it is tire balancing related . Try a Road force balancing machine by Hunter. They have a locater on their web site I had a new set of Warn wheels that were requiring 18 oz of weight for my 37" KO2s. Sent them back and bought MOPAR wheels and same tires took 6 oz

 

[Waffen6]

To reply to everyone torque was not checked on the ball joints or steering gear box bolts as they were never removed. Pitman arm was checked along with the new track bar bolts/nuts. The longer arms are the ones supplied from Skyjacker in the kit. As for the balancing, the machines at my dealer are almost new Hunter machines. They were road forced and all showed in green (under 25 for LT tires). Wheels were all spun bare before install and spun straight. Alignment was set to our brand new (like I was the first one daring enough to use it lol) Hunter alignment machine, but I can redo it and set toe out just a hair to see if that helps.

 

[Maximus Gladius]

torque was not checked on the ball joints or steering gear box bolts as they were never removed.

Trust in that they are loose from the factory. Both upper and lower ball joints and steering gear box bolts were very loose on mine from the factory. My lowers were at 7lbs and I tightened them up to 59lbs, then put on around 50k kms and I just rechecked them this fall and they wore to 49lbs so I retorqued them again to 59. My uppers this fall needed to have the nut turned to the next hole slot.

If my memory serves me correctly, the steering box bolts were down 40lbs from the factory.

Everything was loose from the start but not anymore. It drives very nice. I hate shimmering and vibrations so I can relate to this being super irritating for you. Is there a way to swap out rims and tires to try another “like set”?

 

[Maximus Gladius]

One more thing I had just thought about…

Before my 21 JTR, I owned a 17 TRD Sport Tacoma and after I raised it just 1.5” I had drive line vibrations that drove me nuts. After trying a bunch of things like carrier bearing spacers and diff drops and replacing the needle bearing for the CV axle for a sleeve insert at the front diff, and nothing seemed to work, was going to take the truck into a driveline specialist to have them put the truck on rollers and hook up sensors all over it to locate where the vibration was coming from.

It was then that I had to do a trip to BC and an ELK ran out in front of me and totalled my truck. So I never got to do the test but it never vibrated again after that.

 

[Stan H]

Well, there is your answer . Find an Elk !!?? okay kidding
Something is loose somewhere or it's the toe in . I actually had a vibration on mine turned out one of my rims was slightly bent..

 

[Maximus Gladius]

Well, there is your answer . Find an Elk !!?? okay kidding
Something is loose somewhere or it's the toe in . I actually had a vibration on mine turned out one of my rims was slightly bent..

OP, I’m assuming you have the same rim/tire size for a spare right? Swap out a wheel at a time with the spare and see what happens!

 

[Waffen6]

OP, I’m assuming you have the same rim/tire size for a spare right? Swap out a wheel at a time with the spare and see what happens!

Of course not lol, not yet, $300 for a matching spare was put on hold. Getting bills in from my sons cardiologist so after we get those taken care of its on the list. Will check torque on everything, could an updated steering shock help?

 

[Maximus Gladius]

Of course not lol, not yet, $300 for a matching spare was put on hold. Getting bills in from my sons cardiologist so after we get those taken care of its on the list. Will check torque on everything, could an updated steering shock help?

I’m reaching deep into my physics pocket and thinking that if the vibration is coming from the front, a tighter feeling shock won’t do much.
Sorry if I missed this but did you rotate to see if the “bad wheel” was put to the back?

 

[Waffen6]

Yes they have been rotated, no change

 

[Stan H]

Wheel bearing? Track bar? Tie rod end? Drag link bar ? Ball joints need tightened ?Are all components tight ?

 

[DylanM]

Have you tried playing with the inflation pressure? It's possible the way the shoulder lugs are contacting the pavement is causing the slight shimmy. I'd adjust the pressure five psi up and down from current to see if that improves things any.

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