I drive a Ford

Can someone point me in the right direction with my front end wobble?
Car is a 2001 S600. Steering wheel moves side to side and really the whole front end starts a rapid side to side wobble as if
a wheel was unbalanced or bent.
The wobble only happens between 50 - 60 MPH in this case.
I have had both front wheels balanced and they balanced out good.
If I hit the brakes the wobble immediately stops and the car returns to being silky smooth again.
I believe this is a clue. Applying the brakes STOPS the wobble completely.
Since the brakes stop the wobble, could this be a bad wheel bearing?
Thanks

chassis

Wheel bearing or ball joint/tie rod joint, or control arm bushing.

Is there a growling or humming sound when you apply the brakes hard from 50mph a standstill?

When you are sitting in the parking lot with the foot on the brake, are there any clicking or knocking sounds when the steering wheel is turned left-right quickly?

Any indy shop can do the proper diagnosis for you for a diagnostic fee.

I drive a Ford

So far I have only tried it at about 55 MPH where the wobble will happen and the brakes completely stop the wobble.
There "was" a pretty loud "clunk" with sharp turns before but that has gone away for some reason after doing the strutmaster's coilover
conversion (because my ABC system failed) - not sure why that would have stopped it, but yes, it used to make a big "clunk" on sharp turns.
It doesn't make a humming noise or anything I would have associated with a bad wheel bearing so it has me stumped.
I will probably be replacing a wheel bearing first. Don't want to just throw money at this thing if I can
get it to behave for cheap.......but I know....nothing is cheap about fixing Mercedes.
Thanks a lot Chassis. I really appreciate the help.

chassis

Need more diagnosis. If no humming and you have balanced wheels/tires, the focus is on ball joints and bushings. Did you do parking lot test with foot on the brake and turn the steering wheel quickly left and right? Drive slowly at an angle over a speed bump - any clicking or knocking?

Why will you replace a wheel bearing? What is the reason?

wallyp

Get a helper, preferably a strong one. Do all of this, even if you quickly find a problem.

Using good jackstands to safely support the front of the car, get it high enough for you to get under and see what is going on. You will be jerking and yanking the car really hard, so make certain that you aren't going to get killed - seriously.
Grab a front wheel at 6 and 12 and try hard to move the tire - push at 6 while pulling at 12, then reverse.Any looseness makes that wheel bearing very suspect. If you want a really good check, pry the brake pads away from the rotors and repeat the test.
Get under the car with a good light. Have the strong helper grab the wheel at 3 and 9, then try hard to move the wheel , pushing at 3 while pulling at 9, then reversing repeatedly. You watch and feel carefully for any free play or looseness in the outer steering rod ends. Look and feel (through the rubber boots) for any free play or looseness in the inner steering rod joints.Look for any perceptible movement in any of the arms or struts. Check the steering rack by pushing the steering rod up and down through the rubber boot, and make certain that the rack is firmly attached.
Repeat on the other side.
Carefully inspect the rubber boot on every ball joint on the suspension and steering. Try to move the arm to check for wear in the joint.
Carefully inspect every rubber bushing for degradation or damage.
Inspect the tire treads for any uneven wear (this should have been done while the wheels were being balanced). Rotate the wheels and watch for any side-to-side movement.
Inspect the steering column for any visible or feel-able damage or wear in any of the connections.

Find a smooth parking lot. Hold the steering wheel firmly, and drive across the lot at a walking pace, feeling for any "waddle". Waddle here indicates a crooked or failed belt in the radial tires.

Kebowers47

Something is loose. Check the tightness of the steering rack both externally and play in the tierods. Also carefully rotate the tires and check for any unevenness in radial and lateral directions ---looking for a damaged tire or bent wheel. A lot of brake disc warp can cause this condition but brake pedal pulsing would show up.
I recommend you seek out a GOOD alignment shop familiar with Mercedes Benz to diagnose this unusual problem. This front end is normally very stable.

S430AMG

I like this

For safety I use 4 safety failure point method.

1) jack stands
2) extra jack stands
3) ramps under the wheels in case it falls
3) jack

I also like to have another person on stand by with 2nd jack incase something goes wrong

Yes, it's ridicules, but I refused to be crushed by a car....

I drive a Ford

Because the last time I had it at my local independent MB repair shop they added some notes / observations to the receipt including "noisy front left wheel bearing" and "needs left and right lower control arms" Additionally, I am now seeing the ABS light on the instrument cluster which could be from a bad wheel bearing.
Sorry, I didn't mention that you before and I should have. A lot has gone wrong with it since then and it has not been used for about 2 years.
But, Guess what it was? It was the tires.
Since the old tires had just been balanced professionally I really thought they were OK. They weren't OK.
They were wearing on the inside from negative camber and even though they could be balanced, they caused the car to wobble badly between 50 - 60 MPH. The inside diameter of the tires was less than the outside diameter. You could easily look at them and see they were worn down on the inside.
If this car didn't have directional wheels, I could have figured that out on my own by swapping the rear wheels with the front wheels, but due to directional wheels, I needed to either pay to to have the back ones put new tires on the front.
Sorry I didn't give you all the details on this car as I should have. Thanks for your help.

I drive a Ford

Thank you. It turns out it was the tires. It stumped me because I just had them balanced and I figured if they could be balanced OK then they were OK.
No. They were worn down on the inside from negative camber and they'd balance OK, but at 50-60mph they'd start to wobble like crazy.
Got new front tires. Problem solved. Now I am going to install some parts and get it aligned.
Sure appreciate the detailed reply and I will be using this soon as I replace a wheel bearing and both lower control arms.
Need to do this before I get it aligned.
Amazing to me that so much has worn out in less than 63,000 miles on this car (and the ABC system failed completely).
My Ford Crown Vic would need a lot more than 63k to burn through all those parts!