Jbthompson

Hi everyone. I would appreciate any advice you all could give me. I have an 01 LS with 118k miles on her. I just put new tires on, trying to get a smoother ride. I have also done lower ball joints, tie rods, and sway bar bushings trying to get my car back to a smooth lexus ride. At around 65-70 miles per hour, I am getting a pretty noticeable vibration in the steering wheel.

I've had the car aligned twice, tires balanced, and then just recently road force balanced. When I had it road forced balanced the tire that was on the passenger front was a little overweight on balance, but just a little and my mechanic wasn't concerned about it. Trying to be diligent, I put that tire on the back, but it didn't solve the vibration issue.

I'm at a loss at this point. I know I need new front rotors, and that is next on the list, could that be causing this?? Any help would be appreciated!

LudeAEM

Hmm i was going to suggest road force balancing but you've already done that. I was in a similar boat and putting new front rotors and pads on DID help but not eliminate the issue. Could be drivetrain related but then again if its only happening at speed it makes me question that. Do you have vibration only at that speed or is it just that you only notice it then?

Jbthompson

Its pretty solid up until around 65-70, and then I really feel the vibration. It feels perfect up until then.

rkw77080

A defective/worn rotor can cause vibration at the steering wheel, but only when you apply brake. If the vibration occurs without you applying brake, then the rotor is not the culprit.

I can think of two other causes based on your description. The most likely culprit is a worn shock absorber. The early stage of failure on a shock is its inability to dampen the micro-bounces the tire makes. Unfortunately, most on-vehicle tests for the shock only addresses the big-bounces. The second and less likely culprit is the wheel bearing. If either of these are original parts on your vehicle, they are due for replacement.

Jbthompson

Interesting, thank you. My car has air suspension which is still functional with no leaks, but I know that is something that could go. I was wondering about the wheel bearing. I'm getting tired of replacing parts on this car! Argh.

Jks24

Check to see if your rims are bent they may be the cause or engine transmission mounts may be worn and cracked. Also you may have one I or more defective tires. Tires are balanced at low speeds so it would be very difficult for your mechanic to tell if your tires are defective.

911LE

If the vibration is in the steering wheel try rotating the tires front to back to see if that changes anything. Worn lower control arm/caster bushings can cause vibrations in the steering wheel but usually at lower speeds and over road imperfections. Check them for cracks and/or leaking oil.

BradTank

If you mean the vibration happens when you press on the brake pedal at those speeds? If that's what's happening, it's almost certainly the brake rotors.

Otherwise, it can be a lot of things, but I lean towards a tire issue.

I've had a defective tire purchased new where the internal belt separated in very few miles.
I just recently had a tire shop tell me the tires have been properly balanced only to have to return and have them do it again as they weren't even close, the steering wheel was bouncing all over the place at 65-70mph. I took it back and it was night and day different now on the freeway. The unfortunate reality is many tire shops have employees that just don' t really care all that much. Balancing weights can also fall off the rims, etc.


Also, find the absolute smoothest freeway you can and see if the issue is still there. I have a freeway I sometimes use that they just screwed up on with the control joints, and you would swear something was really wrong with your suspension but it's actually the road. The road is not cracked or old, it was just poorly built. The steering wheel noticeably "thunks" every second in your hands.

jjskywlker

If you are having steering wheel shimmy when NOT touching the brakes, your issue is PROBABLY one of the following, in order of likelyhood.

1. Bent Rim. This can be diagnosed on the Hunter GSP9700 balancing machine most reputable tire/balance shops use, but most mechanics are too lazy to test deeply or really dive into giving you the best ride possible. Suspect rim may need to be straightened, typically outsourced to specialist companies like Alloy Wheel Repair Specialists (AWRS).
2. Bad Lower Control Arm/bushing. Most likely cause of steering wheel shimmy at highway speed.
3. Rotor deposits (warped brakes). Plausible that the brake pad deposits on the rotor could cause shimmy because of runout while at speed.
4. Bad tire balance/mounting position. Same diagnosis from Hunter balancing machine. The tire may need to be moved to a different spot on rim depending on high/low spots. Too much or misplaced weights could also cause.
5. Bad Wheel Bearing. Dark horse, but if you don't have any strange sounds, probably not the cause.
6. Stuck/Frozen Caliper. Least likely, but it could happen and cause the caliper to drag/hold the rotor.


Former owner of BMW E60 with incurable steering wheel shimmies.

ancdmd

I'm gonna lean toward a bad shock absorber for this one. Followed by brake rotors. Bent wheel can be checked by jacking up the car and spinning the wheel to check for runout.

While we're discussing vibration, I left my car for a week with the battery disconnected while I was out of town. When I went to drive it it had a bad vibration above 40+mph. I though I had a flat tire or something. Pulled over and checked it, saw no issues and kept driving. Smoothed out fine after a couple more miles. Could the UL's air suspension cause this? Both my front shocks have about 75k miles on em. One rear has about 80k on it, and the other is original with 181k miles on it. Tires are fairly new, car aligned two weeks ago. Hard to believe tires could be flat-spotted that much after only 7 or 8 days.

Slvr surfr

iTrader: (1)

Your tires ":flat spotted" after sitting for that amount of time. As the tires warmed up from driving, the rubber softened and rounded itself out. My first set of Toyo's did this this only after a day or so of sitting. Although softer tires tend to do this,the new Versado's i have now dont do this at all.

LS430FL

I'll be watching this thread. I have exact same issue. I had replaced tires, wheels, balanced a million times, aligned and I still get the same vibration at 25mph. above or below that and it goes away.

ancdmd

My tires are Toyo T1 Sport, 20".

LS430Lexus

When you feel the vibration through the steering wheel, you should consider motor and transmission mounts. Replacing them usually brings back the smooth ride.

toantran99

Maybe it's the ball joint?
https://www.clublexus.com/forums/ls-...placement.html