[SDLCrazier]

I noticed lately on my E300D that when I was in a harsh braking under high speed, my steering wheel shaked and I could feel it came from right front rotor. Under normal speed, say below 40mph, it's smooth. I tend to believe this is some sorta bushing shot (in early stage), not rotor being warped, but don't know which one.

On my 300SDL, I know there is a guide rod bushing which could cause similar problem and I changed that before. On E300D, it seems there isn't a guide rod, but I am sure there has to be something similar to hold the position of hub when immense force pushes hubs toward the back of the car. Are bushings there? Any graphic/screen shots are appreciated.

 

[gradyg3]

sounds like warped rotors to me. unless shot ball joints could also cause this, any other front end issues like clunks rattles at low speed or vibration at 55-60??

 

['91 300CE]

I 2nd the warped rotors... my rear rotors were bad and I was getting this shake when braking.

 

[loubapache]

I 3rd the rotors. Believe it or not, as 91 300CE said, even rear rotors can cause your symptom.

 

[SDLCrazier]

Wow, 1,2,3 all pointed to warped rotors My understanding is - if a warped rotor is involved, in any given speed when braking is applied, regardless heavy or light footing, I should feel the steering wheel vibration. But in my case, only when I'm using heavy footing (harsh braking in high speed driving), it becomes noticeable.

Interesting thing is - Mercedes changed the frontend design from W126 completely. I am so familar with that on W126, in fact I rebuilt entire frontend myself on my 300SDL. Now W210 is a different animal, I have to start to learn it...

 

[loubapache]

Say there is a piece of coarse sand paper and you use your hand to move across it.

If you apply little pressure, you feel OK (you do not feel much).

However, if you apply a lot of pressure, then ouch (you feel every sand particle).

 

[SDLCrazier]

I buy your story
But if I apply little pressure, I should feel the roughness, don't I? Anyway, I'll go under the car tonight and beat it up at New Year's Eve

Happy New Year, friends!!

 

[e-420]

Wow, 1,2,3 all pointed to warped rotors My understanding is - if a warped rotor is involved, in any given speed when braking is applied, regardless heavy or light footing, I should feel the steering wheel vibration. But in my case, only when I'm using heavy footing (harsh braking in high speed driving), it becomes noticeable.

Interesting thing is - Mercedes changed the frontend design from W126 completely. I am so familar with that on W126, in fact I rebuilt entire frontend myself on my 300SDL. Now W210 is a different animal, I have to start to learn it...

depends on how bad the runout is. If it is mild, you may not notice it on light braking or low speeds, but will on hard braking and at higher speeds.

And it could be either front or rear, my experience is rear is less likely to give steering wheel shake on light braking.

Also I think all (or at least many) W210's have fixed rear calipers. Fixed calipers are much more senstive to runout since the caliper can't float with the rotor. What happens then is the brake puck gets pushed in and out by the rotor causing variations in brake pressure. (instead of the caliper moving in and out while keeping the pressure more constant) This then can cause the braking forces to vary side to side and try to move the rear of the car around. You feel that in the steering as the forces on the steering wheel vary. It is possible a stuck rear piston could give the same symptoms.

I once had a car with fixed front calipers, it was extremely sensitive to rotor runout.

Other possibility (more remote) is a tire with a broken or misaligned belt or tread. Although you will usually get a vibration that is speed sensitive as well, and it is just more noticeable as you brake.

 

[loubapache]

Do it next year.

 

[SDLCrazier]

Thanks e-420. So most likely it is the rotor...
Lou, I'll take your advise, wait until next year but I am afraid I might not be sleeping well without fixing the issue ~~