Hello, the car drives near perfect most of the time. Between 65-70 I get a very slight vibration and remains there as fast as I dare to drive. Most people who ride in the car don’t notice it, but I do.
Tires are approximately 6 years old and have excessive road downforce as measured by Discount Tires. ~35 lbs down force, like a truck.
I going to start replacing first fronts then the rears. See where that goes.

Is there a method to inspect the driveline for excessive wear? Is the driveline two pieces with a bearing in the middle?

A member mentioned they had a vibration in their S600 at 65mph, changed out the upper/lower control arms and that fixed the issue.
Is there a method to inspect the upper/lower control arms for excessive wear before spending boo coo money?

Low hanging fruit would be the tires…

Thanks,
Johnny

mine does it... comes and goes, at times its shocking, at others you forget its there - swapped tyres thought it helped but it came back

all the posts about prop shaft centre bearing support being tired jogged my mind the other day - maybe its this

Lots of folks have had this problem, me included. What worked for me was changing out the control arms and tie rods, which took care of 95% of it. Then, I bought a new set of OEM wheels...problem gone. My old wheels which had been straightened were just not straight enough--despite what the wheel repair shop said.

It is two problems. I had the same problems. Changed out the entire front end components with new FCP OEM parts. Upper and lower control arms, forward and rear, and tie rods. Technician also said the OEM wheels are easy to bend (duh!). He suggested wheel repair; I bought remanufactured for the right rear. That took care of it. Wheels were hard to find.

It is definitely those lower control arms. They are also particularly difficult to check for wear. You need to put a load on the suspension when you grab that wheel and shake hard. I replaced mine at 92K miles.

I assume you use original wheels but if you don’t make sure centering rings are used when mounted on the hub.

.... I have an issue at the rear of the car - which is what I thought the OP was saying...

wheels offset on the hub is what makes the front play up

Thanks folks for the suggestions.

To keep the costs in check, the repairs will need to be categorized by cost and historical evidence.

The age of the tires are ~ 7yrs, with very excessive road down force as measured. The rims look perfect. Could be reworked rims though.
New tires would reveal a fouled up rim.

Next on the list would be the upper/lower control arms. Probably not a weekend project, more a of a shop procedure?

Anyone have a drawing and procedure on the the driveshaft from transmission to rear differential?

Johnny

90+ percent of vibrations on the freeway are going to be tires/wheels. Seven year old tires? Toss them now before one decides to blow out for a torn up fender liner or worse. Very often a wheel that is not perfectly straight will make a mystery shake. It balances out OK on the machine but it shakes on the road.
Driveshaft vibrations are at Differential ratio times MPH for how fast it shakes. Figure Wheel speed X 2.5 roughly. Feels very different from a tire/wheel shake.
A C/V shake will be only under load. Usually at higher speeds. Lift the loud pedal and shake stops.
Suspension components that are soooo worn as to contribute to vibrations are a clear indicator of an owner who is not looking after his junk.... Also... Suspension parts will make a tire/wheel/brakes shake more dramatic.... not be the root cause of a shake.
Take care of your junk guys!

Totally agree on the wheels. Our alloy wheels are made from chewing gum wrappers. I'd really like to find a decent looking set of non-OEM wheels that would fit in with the look and presence of my S600. My Mustang and SRT8 wheels never had any problems.

And it never helps when I clip curbs or hit dividers. Just bought a new rear wheel and one day later, backed into a curb. OEM 19 inch wheel from the dealer, $870 plus a core charge. It just never stops.

Starting to make sense the different types of vibrations. If cruising at 70mph, vibration is constant, tap it into neutral, no torque loading, and vibration remains unchanged, it’s looking like rims/tires.
Gonna get 2 new front tires and verify road down force is measured low, under 10lbs, like it should be, and road test.

Johnny

What happens in the front of the car that is a useful diagnostic tool you ask?

There is a large round tool in front of the driver. It doesn't just instruct the car what direction to go but provides useful feedback to an attentive driver.

Where there is a vibration in the front of the car that large round tool in front of the driver will shake along with the front wheel(s).

No shake there? Where else might we look? Hmmmm

from gearbox to the back wheels

How many PSI do you run in your tires? Pro-tip.... Give them 44psi and aside from curb rash you won't be replacing wheels. A pothole will still wipe out a tire but the wheel has a LOT more protection. Yes, you will feel more bumps but if the goal were a pillow soft ride we'd get there with 15" wheels and an 80 aspect ratio tire and 30psi. LOTS of sidewall to deflect. Alas those won't fit over modern brakes.

Ladies and Gentleman we have a winner!

Overwhelming percentage will still be wheels and tires.

Good morning Botus. 14:00 for you?

yep (so good afternoon)

The more researched, the more common this issue seems to be.

So far:
Replaced 2 motor and 1 transmission mount. It felt like tractor before, after it felt really smooth. No change in symptoms.

4 new tires balanced to maximum precision, numerous times. No change.

Warped front rotors. Replaced. Back brakes looked like new, parking brake operated like new, kept the rear brakes. Brakes work fantastic now. No change in symptoms.

Replaced front rubber driveshaft damper doughnut. Was cracked and missing pieces of rubber. Back one looked like new, kept it. No change in symptoms.

Next move is follow Tech Bulletin below at the recommendation of the shop and replace the front torque strut bushings.

LI00.90-P-050323 – 221 except 4MATIC, steering wheel vibrations/shimmy @ highway speeds. Vibration caused by wheel/tire balance/uniformity; torque strut bushing; or steering rack (vehicles with EHPS up to VIN A351230)) "

If that doesn’t cure it, I’ll round up the cash to replace the upper/lower control arms.

Johnny

OP did you get to see the wheels without tires on them?

When I’m chasing after a PITA vibration.... I have got to enough times for clients.... I have all the tires dismounted and mount the wheel up in the balancer. Now we can slowly turn the wheel under a bright light while looking closely for any imperfections on the surface the bead of the tire sits on and against. Spots where the wheel has been welded in the past will be easy to see. Spin just the wheel in the balancer. See ANY runout in the wheel? Throw the wheel away. Chrome wheel? (Throw it away) Look for galvanic corrosion all along the bead surface. Then throw the chrome wheel away when you find little spots of it everywhere the chrome comes close to the bead. Chrome wheels famously lose air due to corrosion between the dissimilar materials. Live where there is anything applied to the road to melt snow? It will be many times worse than for cars that live in a warm climate.

I understand your priorities. I bought new Michelins from Tire Rack, refurbished wheels (some improvement), replaced front suspension components especially the lower control arms (more improvement), and just replaced ABS struts (best improvement so far). I am guessing you need lower control arms.

I think I posted this before. Are your rims otiginsl MB rims or after market?

If after market they usually have too big hole in the middle so they fit more cars. With these rims you need to use centering rims so the wheels are properly centered on the hubs.

I had the problem with my 2010 E550 and it started vibrate almost exactly at 65 mph speed. Three tire balances and using conical centering lug bolts it still vibrated. Problem was completely solved by using centering rings.

If wheels are MB wheel they should fit snuggly on the hubs and the above should not apply.

My experience of front suspension arms in the 221 S65 being they needed replacement annually.

They are weak junk.

Can’t say they ever contributed to a vibration. They would squeak and clunk as the ballpoints wear.

As mentioned above.... the wheels MUST be hub centric. I have seen wheels corrode such that the spot where it meets the hub is loose. Yup; a shake.

Hi Arrie, I remember you posted about the importance of centering the rim to rule out the source of the vibration. My rims I believe are MB.


These are the rims which arrived on the car. I’ve seen other cars on the internet with them as well.

I found again in the forum this vibration turned on for many folks at about 90,000 mile.

I’ll know more Monday as I’m taking it in to have the torque strut bushings replaced.

I’ll update next week week.

JR

it didn't help some are responding on the brake thread you ran this week - yes those are rare Merc OEM rims

check out the bit about the inner ball joints on the steering rack I posted there

Hmm did the OP follow John Lane's advice to dismount the tires and run the bare wheels on the balance machine to check for vertical and lateral runout ? He did say the wheels were "refurbished"..So rather than starting with suspension parts, I would start by doing what John Lane said. Double check for the wheels being hub centric too as well as the mating surfaces being 100% flat. . Just because they are a rare MB OEM doesnt mean they are in good form and hubcentric with great mating surfaces. if they dont mount up properly they wont balance correctly.

Do it right or burn money and still be disatisfied.........

Hi Folks,
Thanks for the cautions about verifying the simple and cheaper first. I’ve had the rims, new tires balancing and runout verified numerous times at different tire shops.
The last shop was “The Wheel Doctor”. He used to be a real medical doctor, but he found there is more money to be made in wheels!
The verdict is the tires are balanced and hub-centric on the spindle and holes. Doctor Wheel even cleaned the spindle and rims with a wire brush. No change in symptoms.

Tomorrow getting the torque strut bushings swapped out with liquid filled ones from the all wheel drive S550 as suggested in the tech bulletin.

if no joy, I will focus on the upper/lower control arms.

Johnny

Well drove it today after the torque strut bushings installed, and no change in symptoms. Had to die trying.

Next steps is to replace the upper and lower control arms.

Anyone have any suggestions like just replace the lower arms?

Johnny