Help diagnosing vibration

So I've had some annoying vibes in my car for a while now. It's more noticeable at higher speeds and I had been thinking it was just that one or more of my wheels were out of balance. I figured maybe I threw a weight or maybe damaged a wheel on these shit roads. Well last Friday I took it to Chris at DT and they balanced all the wheels. They said that 2 of them were out of balance.

Problem is, that as soon as I hopped on 94 I knew that not only had the problem not been solved, it had actually become worse. On a smooth road you can start to feel the vibration around 45mph. When you get up to 80 it is quite strong. I can feel it through the pedals, the floor, you can feel it in the back seat, as well as through the steering wheel.

So now I am trying to explore other possible causes. Some things that have been suggested to me are:

steering rack damaged: seems unlikely to me, but not ruling it out
warped rotors: presumably from over tightened lugs. seems very unlikely. I always use a torque wrench on my lugs, and DT does too.
wheel bearings: I guess this one is plausible, but it seems odd to me that a bearing(s) could be bad after only 46K miles. However, I do have quite a bit of noise while rolling. I thought, and still do, that most or all of this was from my Falkens, which I've heard are a noisy tire. But I guess I can't rule out that some of the noise might be from bad bearings.

Someone said that you can check the bearings by jacking up the car and grabbing the wheel and trying to move it side to side. I might try that tonight.

Any other ideas/input?

Every car I've seen, if it's not wheels/tires, it's control arm bushings.

That would be nice, but this is a really strong, rhythmic vibration. It's almost like a really quick thumping. I dunno it's hard to describe. Could those cause that and be bad after only 46K?

First: Same size tires all around? Even though you just had them balanced or whatever, you should swap them front to back and see if the vibration changes. Then you'll know it's a wheel/tire problem.

Second: Check tie rods, then ball joints/control arm bushings. Worn or damaged tie rods cause vibrations like this all the time.

Yep the tires and wheels were put on new last summer and are the same all around. I only have about 6500 miles on them at this point. Actually they did swap the wheels front to back. (they are directional tires). It's subtle, but the vibration did change. Could I have a bent or warped wheel? They balanced all 4 so I thought that would have been something that would have been detected in that process.

halo0 wrote:

Yep the tires and wheels were put on new last summer and are the same all around. I only have about 6500 miles on them at this point. Actually they did swap the wheels front to back. (they are directional tires). It's subtle, but the vibration did change. Could I have a bent or warped wheel? They balanced all 4 so I thought that would have been something that would have been detected in that process.

Balance isn't the only thing in a tire that causes vibration. You need to switch the tires back and forth without changing any weights or pressures so you know for sure.

OK so say I swap them again, and the vibrations change again. What would that indicate?

halo0 wrote:

OK so say I swap them again, and the vibrations change again. What would that indicate?

That it is one of the wheel/tire assemblies that is causing the vibration. Wheel-related vibrations will almost always show up on a balance, but tire-related vibrations could be a belt- or tread-related problem in the tire, which will not show up on a balance.

Edit: That is unless it is a hub or lug problem, but you should be able to spot that by jacking the car up with the lugs tightened and grabbing the wheel.

My tires have a very mild cupping according to Chris. I wouldn't think that could cause it.

A belt-related problem would have to mean a defective tire? Or could that be caused by a pothole?

halo0 wrote:

My tires have a very mild cupping according to Chris. I wouldn't think that could cause it.

A belt-related problem would have to mean a defective tire? Or could that be caused by a pothole?

Cupping can cause a vibration and it's also a symptom of other things that cause a vibration. A broken belt in a tire comes from a defect or an impact, correct.

Phil, you should still check your tie rods, ball joints, control arm bushings, etc if you have cupping on a tire.

I'll try checking that stuff when I get home, and the bearings. I'm not 100% confident in my ability to identify such a problem, but hopefully it will be obvious. If not I guess I will switch the wheels around again and see if anything changes.

i would do as corey said, just check everything and make sure they are in proper working condition, tie rods are checked by shaking the wheel with your hands on 9 and 3, wheel bearings are checked at 12 and 6 also by shaking the tire, you should have no movement, then check to see if you have any exposed grease near the ball joints, just saying this if you didnt know already, also from what i can read, it must be a tire problem, maybe because of your negative camber in the back

Thanks you guys. I hope I can find some clues and don't end up back at square one.

Ask some times tires can shift on a rim and be kind of lobe shaped while rotating. If u balance the tire like this it will be more pronounced. I can look into a road force balance at toyota. Sometimes the tires need to be dis mounted and remounted to fix this. In order to rule out a wheel issue slap on your snows?

yeah if I can't find anything else that looks bad I probably will throw on the snows tonight. thx!

Well I checked all the suspension components and they all seem fine. (upper strut mount, lower control arm, cv joint, tie rods). I could not cause any movement from the hub/bearing by trying to rock the wheel at 12 and 6. I checked all 4 wheels for free spinning movement. On both fronts and one of the rears I could detect just the slightest sound during one section of the rotation that would seem to indicate the pad brushing the rotor there. I'm not even sure about the fronts due to them being connected to the tranny and not really spinning freely and I had to put my ear close to hear it. On the one rear one it was pretty slight as well, if you gave the wheel a bit of a spin it would fly right by the high spot, but if you spun it really slowly it would stop there. I don't even have a garage. let alone a way to measure disk runout. What would cause this and what do I do now?

Sounds like a little warp but nothing to sweat. If u want to check for warped rotors; drive the car in a staight line and the brake at medium level with hands hovering over the wheel. What your looking for is a slight shimmy in the wheel when u first slam down the pedal. That means u have warped rotors up front. How much the wheel shakes is how much warp u have. Good luck and keep us posted!

There is no shimmy or change in the vibrations under braking. That's why I wasn't expecting warped rotors.

You have to do it while not holding the wheel at all, have you tried that? Josh explained to me last night that it's possible for the shimmying to not be recognizable from the feel of the hands, but can be seen when you don't have any pressure on the steering wheel.

I want to say it's a tire and wheel issue. Prob not a real bad one. Just an annoying one.

It feels pretty bad.

I've def seen steering wheel shimmy before from bad rotors. I will try the no hands thing but I' doubting that's it.

it doesnt sound like your brakes are warped to an extent where it becomes noticeable, but back to your tires, what is your pressure at?

I can't help any more without looking at it myself.

I appreciate the help. I'm going to try putting the snows on in the morning. I just have a gut feeling that it's wheel-related, due to the way the frequency and force increases with speed.