Unexpected Wobble Fix?

[mtbjeep]

Good morning all. Last December (2022) I had a MC 2.5" True Dual Rate lift installed on my 2018 JLU Sahara. Along with the lift I installed 35" Maxxis RAZR AT tires on my stock wheels. Upon picking it up I noticed that it had a definite shimmy that turned into a full blown wobble with the right bump and right temperature (<35f). I took it back to the shop to troubleshoot and they did absolutely nothing to help me out. Really disappointing because they had been great until the check cleared. Rolling into spring, with the return of warm weather, the problem almost disappeared. Nonetheless I had it on my radar to establish a relationship with another shop, and address the issue when the weather started to turn cold again.

So this past November & December the new shop tore into the Jeep and did everything we could all collectively think of. Worn parts were replaced, everything was re-torqued, ball joints were replaced, ball joints were re-replaced with another brand, stabilizers were swapped, geometry correction brackets were installed & removed, tire pressure was played with and we aligned, re-aligned and checked the caster throughout. Nothing made the slightest bit of difference. During this process the shop Owner and lead tech had suggested changing the tires on multiple occasions; perhaps there was a defect in the tires causing the issue. I routinely pushed this suggestion aside as I had rotated the tires 3 times since the lift was installed and the problem never went away. The chance that all 5 tires had some unseen issue seemed impossible to me. Well, with 5 seconds left in the 4th quarter before we burned the Jeep to the ground, the tech again made his tire suggestion. Shortly thereafter, rolling on stock tires and rims from another Jeep, I headed to a stretch of road that had become known as Death Wobble Alley. Wouldn't you know it, not a single shimmy, wiggle or wobble.

I ask the collective brain here how is that possible? What could possibly be wrong with the tires that causes shimmy & wobble when they balance just fine and run smooth as silk?

I'm going to have to abandon these tires and spend a small fortune on new tires; but before I do I am beyond curious as to the why...

Thanks!

Mike

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[BDinTX]

Not certain on the exact tire you got but it looks like all their 35" ones are E rated sidewalls. I imagine that would tend to transfer more road shock through to the suspension rather than absorbing it. I'd say it still indicates something is worn out and needs to be replaced though.

Did you also replace the stock drag link and tie rod when the lift went on?

 

[mtbjeep]

Yes the tires are E rated. I ran them between 26 & 35 pounds and no change; I'm thinking the lower end would mitigate the sidewall impact. As part of the lift I replaced the drag link and tie rod with MC parts.

 

[mwilk012]

Put on some 35" michelin defenders and recheck. It will wobble. It's a mass problem.

 

[Upnarms]

I actually find e load tires reduced wobble in my experience. Slightly stiffer sidewalls may be why. In my experience with a Tj, JK, and now JL, trackbar was usually the biggest factor. My tj, i put in a stiffer tb bushing and larger diameter bolt. Got rid of dw but had a little shimmy. Went to a different tire (yoko geos) and shimmy gone too. Now i run wildpeaks on both my tj and jl no issues at all with dw or shimmy. I 5 tire rotate every 2.5k miles. My JL, got dw at 23k miles on ko2s. Steersmart's yeti hd trackbar with pro bushing, no dw. Had a little shimmy so, got wildpeaks and no dw or shimmy 25k miles later. (In fairness i also upgraded my tie rod and drag link to apex 2.5ton during that time, but not initially.)

Tires play a huge role if they dont balance well. Huge. I find many mt's dont balance well as they wear. Also many at's can have same issue if they dont wear well. The tire out of balance is like the spark that sets off the wildfire of dw. I don't know what track bar you run, but get the most hd one you can with the stiffest bushings. And nothing wrong with e load tires. Mine feel just as comfy as the c load ko2s. I air down to around 20 or less off road.

 

[Old Jeeper]

Good morning all. Last December (2022) I had a MC 2.5" True Dual Rate lift installed on my 2018 JLU Sahara. Along with the lift I installed 35" Maxxis RAZR AT tires on my stock wheels. Upon picking it up I noticed that it had a definite shimmy that turned into a full blown wobble with the right bump and right temperature (<35f). I took it back to the shop to troubleshoot and they did absolutely nothing to help me out. Really disappointing because they had been great until the check cleared. Rolling into spring, with the return of warm weather, the problem almost disappeared. Nonetheless I had it on my radar to establish a relationship with another shop, and address the issue when the weather started to turn cold again.

So this past November & December the new shop tore into the Jeep and did everything we could all collectively think of. Worn parts were replaced, everything was re-torqued, ball joints were replaced, ball joints were re-replaced with another brand, stabilizers were swapped, geometry correction brackets were installed & removed, tire pressure was played with and we aligned, re-aligned and checked the caster throughout. Nothing made the slightest bit of difference. During this process the shop Owner and lead tech had suggested changing the tires on multiple occasions; perhaps there was a defect in the tires causing the issue. I routinely pushed this suggestion aside as I had rotated the tires 3 times since the lift was installed and the problem never went away. The chance that all 5 tires had some unseen issue seemed impossible to me. Well, with 5 seconds left in the 4th quarter before we burned the Jeep to the ground, the tech again made his tire suggestion. Shortly thereafter, rolling on stock tires and rims from another Jeep, I headed to a stretch of road that had become known as Death Wobble Alley. Wouldn't you know it, not a single shimmy, wiggle or wobble.

I ask the collective brain here how is that possible? What could possibly be wrong with the tires that causes shimmy & wobble when they balance just fine and run smooth as silk?

I'm going to have to abandon these tires and spend a small fortune on new tires; but before I do I am beyond curious as to the why...

Thanks!

Mike

YES, it's possible!!!!!!!!

100% of the components from the firewall forward that have any connection with the suspension CAN Contribute to DW, do not forget this!

I have been dealing with DW since the 60s on my car and on my Harley, on my John Deere tractor, and on my Jeeps. I owned a Jeep shop for 9 years and dealt with it.

When attempting to resolve DW you start with the basics and the simplest solutions: You would be surprised at how often one of the investigations below led to solving the issue.

Sadly most shops start with under frame suspension components ignoring those below that are easy to deal with. Of course, you don't make as much money selling 2 shocks or equalizing the PSI in your tires, etc.

NOT in any order

Shocks & SS: Failing shock or shocks, leaking shock fluid

Tires: PSI = across the front? Tires balanced? Tires inspected for internal damage...belts can get torn internally and slip causing unbalanced REACTION to input

Ball joints/wheel bearings: Loose

Settings: Caster, Camber, Toe in/out: NOTE, Caster is directly affected by the size of your tire, the taller the tire, the longer the wheelbase and that has to be compensated for.

TRACK BAR: The track bar has 1 (ONE) job, to locate and stabilize your axle from lateral oscillation... The Steering stabilizer is responsible for the mitigation and management of the lateral oscillation.



Past that you dive into bushings and torque of the assorted nuts and bolts.

DW is often a progressive disease meaning that it becomes not one item to replace due to wear and tear of the DW but multiple wear and tear results from a failure to fix DW the FIRST time it was noticed!

There I was in my truck running down the highway trying to loosen my load with 7 women on my mind.

Suddenly I hit some railroad tracks and DW announced its presence. I pulled over, slowed down, restored its driving, and started looking for an Auto parts house

One block later a NAPA pulled in, they had an SS that fit my truck in stock, I asked if it could borrow a few tools, and I crawled under and installed a new SS and life was good again...knowing I had not damaged a lot of other components in the wake of the DW. SUGGEST ALL TAKE HEED!

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