galaxy7

So I have a bit of a wobble/shimmy type thing going on at speed. Not really a vibration, but a wobble. It starts to come in around 40, and then it's gone again just over 60. Repeatable...does it every drive. So far, I've had it up in the air (twice) and checked everything. Can't find any loose or damaged components, nothing wrong. Took the wheels off and had them balance yesterday (because I was sure that was my issue; that's what it feels like). Back on the car and the wheel balancing made zero difference. Didn't change a thing.

Any thoughts? What would you guys look for or try next? I know something like can't really be diagnosed on here, but looking for ideas on what to check or what to look for. Thought about an alignment, but car drives straight and great, and tires are wearing perfectly.

MoonBase

How long have you had the car? When did this issue first show up? What tires and rims do you have? How many miles on the vehicle? All OEM suspension components? Is it lowered? AWD or RWD? As much information as you can provide will help narrow down the options.
Long shot, but Is it possible you have bent rims from an impact or pothole? Probably more common if running aftermarket wheels (replica vs authentic vs OEM).

galaxy7

Bought the car in Jan '20 with 80K on it. It has 120K on it now. Issue showed up maybe 1,000 miles ago. The issue started gradually, but ramped up fast. In other words, it didn't just show up one day like an on/off switch. But it has not progressed worse; it's the same all the time. Car is bumper to bumper, bone stock, 2013, AWD. To the best of my knowledge, no single "event" occurred to start the issue; hitting a big hole, things like that. Like I said, car drives great and can't find anything obvious underneath. Hoping not to just start throwing parts at it, and honestly, wouldn't know where to start anyways, since I can't identify anything.

MoonBase

How old are the tires? Had an old car back in the day that did something similar to what you are describing. Turned out it had blistering tires. There was a bulge in the tire (opposite of a flat spot) that would "bump" every time it went around.
On the topic of alignments, LesSchwab (or another comparable tire/wheel shop) will CHECK alignment for FREE & tell you if it is needed or not. They should give you a printout of the current values vs the OEM reference acceptable ranges. At least then you will know for sure.

Does the wobble speed up or slow down along with your travel speed? Is it a vertical or horizontal wobble? Is the sound audible, or only something you can feel? Present only around a specific speed range? Can you feel the wobble in your steering wheel or does the steering wheel shake? Able to tell if it is coming from the front or back, left or right? When was the last time the transmission or differentials were serviced?
Not sure about lexus rotors but if they're the same as some toyota rotors, they can be fairly easy to warp when driving long & hard or down the mountains. Particularly if towards the end of life and are thin. I have never had them warp permanently, only temporarily. Seemed ok after they cooled down. Had a few Camry's in the family stable and every one of them did this after a long mountain roadtrip.
Do you let anyone else drive your car? Maybe they though everything was fine and an "event" was not worth mentioning since there was no visible damage.
Ultimately, take it to a shop or someone you trust. Put it up on the lift and start poking around. If you can reproduce the wobble while a technician is in the vehicle with you, that may help the diagnosis.

It's not much, but I hope it helps.

Protholl

Ditto on the tires. A slipped belt can cause this and its hard to see on the tire. Try rotating your tires and see if it gets better or worse. If it is a slipped belt moving from the drive axle to the steering axle (or visa versa) would make the wobble behave differently.

2013FSport

iTrader: (2)

IME slipped belts often have low speed wobble 5 - 15 mph. Bent wheels can vary but generally get worse as speed increases past 40mph.

Drive shaft issues have a magic number of 40 to 60mph.

OP, what is the service history and was anything done to around the time this began? Was there any brake work that had the rotors off as rust under a rotor can cause hard to detect wobbles but one would usually notice the brakes pulsing too.

I'd start by checking tire / wheel run-out and verify tire is concentric.

Gville350

iTrader: (10)

Checked the wheel bearings?

galaxy7

Tires are brand new; less than 5K miles. Rebalancing changed nothing. I rotated today anyways to see if it matters. No play in any hub or wheel bearing. Don't see anything apparently wrong with the driveshafts, but sitting still...who knows. Nothing was done, service, accident, nor otherwise, when the wobble started. The wobble is not in the steering wheel. It's predominantly in the body/car. Yes, the wobble changes relative to speed, both speeding up and slowing down, through that 40-60 window. It does seem like the wobble is noticeably worse when on the gas vs coasting. Even in the bad spot.

galaxy7

OK, so you guys gotta check this s&*^ out! I had all the tires balanced the other day, but I brought them home and put them back on the same corner (adjust one thing at a time, right?). Well, last night I decided to rotate them because...well...why not?! And believe it or not, rotating the tires completely fixed the problem! W...T...A...F?! Just based off symptoms alone, I suspected a tire problem all along, but...when I rotated, it cured the problem. I fully expected that if it was a tire/wheel problem, rotating should move the problem, but not eliminate it. Now I have even more questions than I did to begin with, lol. I did a traditional rotation,(front to back, back to front), no cross rotating or anything like that.

Why did this work? Why did the problem not transfer to a different spot in the car?

I will say this...now I fell like the car pulls/leans to the right in the steering wheel more than before. I am fully aware that I'm hypersensitive to the car because of the troubleshooting, but it's still real. But I'm still pretty confused how rotating the tires fixed the problem instead of just moving the problem.