rondocap

I don't know if it's just me, but for some reason today I thought my car's steering wheel was vibrating more than normal. I would not really feel it in the car, just the steering wheel and a little bit on the pedals.

Is it normal to feel any vibration in the steering around 60mph? Or should it be completely smooth?

It snowed in the morning, so I thought maybe some snow got in the wheel well or tire, but the roads have been clear and I still got some vibration around 60mph, and sometimes at around 30mph too.

I know my rear flex disk is a little bit cracked, could that possibly cause some vibration? It's very minor. I also got motor and transmission mounts in recently, possibly they were not put in 100% tightly?

Any ideas would be welcome, I know vibrations are a common question and hard to diagnose!

Skylaw

Vibration can come from a lot of sources, and yes, it includes the flex discs.

It can also be tire runout, wheel balance, bad engine mounts, worn-out transmission mounts, suspension/steering linkage wear, a bent or out-of-round wheel, and other things.

You have already addressed some of these things, but the best way is hands-on. Your MB tech can eliminate some of these things by putting the car on a proper lift, checking tires, wheels and linkages, and also running it, and using a stethoscope on drive train components.

Without proper diagnosis, you could wind up replacing a lot of expensive parts and not fix the problem.

rondocap

Yeah, that's my next step. I know my rear flex disk has a crack, so it could be it. I also feel the vibration through the gear shifter.

Here's a question: I know my Thrust Arm ball joints and bushings are worn. I had my lower control arm ball joints and bushings replaced before. Do new thrust arms come only with the ball joints? (i.e I need to replace the entire arm?)

And how do the forward thrust arms differ from the control arms? There are 4 arms in the front suspension right? The lower 2 are control arms and the upper 2 are forward thrust arms? Any diagram of W220 suspension anyone can link to me?

Thanks!

rondocap

Had it checked further - the flex disks are fine, and not causing this particular vibration.

My wheel bearings are worn - could this be a cause for it?

Gondon

I just did alignment and my vibration is gone.

rondocap

Were you drifting to one side before? My car goes straight, so I don't think an alignment may help.

I mean, I don't know what to do aside from just switch out parts - flex disks, wheel bearings, maybe thrust arms.

nachilus

I bought some 19" wheels and getting vibrations at 65+ MPH. I road force balanced the wheels multiple times at the dealer and goodyear using the hunter machine, still the same issue. I changed:

-Tire rods
-thrust arms
-engine and transmission mount
- still no good

The vibrations seems to be from the rear, the dealer tested and checked the entire suspension but still no resolve. The Wheels are hub centric and both the dealer and the goodyear shop verify the wheels and tires are without issues. the tires are Hankooks.

Here is a picture of the wheel.

rondocap

Did you ever figure it out? I know my thrust arms are a bit worn, their ball joints + bushings too. Are the ball joints a permanent part of the thrust arms, or do they come out like the control arm ball joints?

My rear flex disk also has a minor crack, but they said it's not enough to cause the vibration..

Gondon

there was vibration on the right wheel due to negative camber. Yea it pulled a little to the right but I never got it since new arms. The wheel was literally crooked.

tusabes

Put the old wheels back on and see if it stops.

Im willing to bet money its the new wheels. There are so many ways new wheels might not fit 100% perfect and cause vibration.... Ive had vibration many times when putting custom rims on...no way to correct it but going back to the original rims. Adapters, hub centric rings, etc its all bandaids.

nachilus

I sold them, i may have to get some 19inch factory wheels to see the difference; used of course.

tusabes

a very high percentage of used wheels , even factory ones, are sold due to damage or vibration issues. be careful.

If possible buy them locally and testdrive them on the existing car, or meet at the tire shop and put them on yours so you can testdrive them on your car before finalizing the sale.

The quick and cheap way to find out for sure is to just go to the dealer and have them rotate a set of "takeoff" factory wheels for $40 or so, and see if that cures it. Then you will know for sure if its wheels.

rondocap

I think I solved my problem. I had not checked my tire pressure since i had the vibration, but I had checked my tire pressure about 2 weeks ago. Since then, I had some service done on the car, and I guess they check the tire pressure and adjust it.

I usually have 34 PSI in the back and 32 PSI in the front.

So I checked them today..and the fronts were 29 PSI, and the backs were about 37 PSI.

That's a big gap between them I thought. I readjusted the tire pressure back to 32/34, and pretty much most of the vibration had gone. This was the cause. There really is a feel to the tire causing vibrations vs another part of the car, such as the drivetrain (Flex disks, etc).

I did not know that having them that far apart in pressure could cause vibrations like that. Is that right? Anyone else experience this?

my06clk

You need new tires. A good set.

nachilus

what tires are you running now?

Gondon

That doesnt make sense.

I run 35/40. We got a staggered set up.

rondocap

I've been doing more test driving, and lowering the psi did help a bit, but I still occasionally feel the vibration. Which leads me to the question:

How much road feedback is actually normal for 18 inch wheels in an an S class? I am not sure if what I feel now is normal road feedback, or slight vibration that would indicate a tire or other problem.

Gondon: What do you think of the 35/40? Is the ride harsh?

Gondon

I don't even know it just rides like a smooth tank.

I remember some guy on the E55 boards was running this with his 19's