Hello all,

I’m experiencing a vibration issue that I’m hoping someone here may shine some light on or have experienced.

First off, I did have a vibration that I attributed to rotors, it was evident when braking, felt through the pedal upon braking. Prior to that I had replaced the Pirelli run flats with Michelin AS4s, the road noise and ride quality improved but of course, the vibrations were still there and I knew it was the rotors.
I replaced the rotors and pads all around, the vibrations while braking went away. Everything is butter smooth now until I hit highway speeds.

Around the 70-85mph, I get this constant vibration that is felt through the whole car. If roads are rough, it’s not even that noticeable, but when there is a stretch of smooth new road, it’s evident that there is a vibration that isn’t suppose to be there. It’s clearly not from road imperfections. I thought maybe the tires (approx 7k miles now) were out of balance. Took it in to balance them and the tire tech said two tires were barely out of balance, but they replaced the weights and now they’re practically near 0 and shouldn’t be able to feel anything. Hoping this solved my issue, I took it to the highway again and the problem still exists. So this morning, I took it to another tire shop and explained everything and requested a road force balance. I saw them test each wheel and tire, with the laser going on the rim and everything, I asked them to check for bent wheels etc. since the forums here say that’s very common. The tech said two wheels and tires were perfect, the other two were near perfect and well below the minimum specs and I shouldn’t feel anything from those at all. I have the factory 19 inch wheels and they’re in pristine condition, not a single curb mark on them.

So, they recommended to have the suspension or drive line checked. That brings me here. Any recommendations on what to look out for? I’ve checked each wheel for bearing issues by trying to see if there’s any play in all four wheels. Everything is solid. Visually, control arms, struts, ball joints, are all tight and I can’t even move them with my hands. Even the little sway bar links are all solid. No obvious signs of any torn boot, leaks, or anything from any suspension component as far as I can tell. I’m probably going to take it to an independent shop to have them double check those things though. My next guess is the “driveline”.. drive shaft center bearing and support? Flex discs on both ends? Transmission mount? I haven’t inspected those yet other than the tranny mount when I did the tranny fluid several months ago. I noticed the mount was aftermarket, so I could assume it’s probably bad now. I only suspect that it’s aftermarket because I couldn’t find a single part number on it. I doubt the original comes like that. I was hoping to get the part number so I could replace it while I was doing the tranny service, but never got around to replacing it.

About the vibration, it’s not severe but it’s definitely felt throughout the whole car, not specifically the steering wheel or pedal. It’s almost like the whole floor of the car? It’s probably not noticeable to most people, but I’m not used to it. I had a w212 that was butter smooth on the same roads. So I know it’s not normal, considering the w222 should be better. The vibration does not go away if I shift to neutral, or manually down shift through the gears. It seems to vary with speed, within the speed range the issues are present. I didn’t really drive faster than 85 but it appears to start to diminish as I went faster than that. The sweet spot is really 70-85. If I sway left or right while the car is vibrating, it doesn’t change anything, I was trying to see if it’s possibly bearings. It doesn’t make any noise, except maybe, a very very small “whine” that might not be related to the vibrations. That whine is heard as I’m coasting down in speed from maybe 70-55mph, its frequency changes while speed is dropping until it’s no longer heard. It’s almost like one of those coil whine interference you hear with AM/FM transmitters. It might be related to the vibration, maybe driveshaft bearing going out?
Another thing, it doesn’t always happen at exactly those speeds. It’s gradual, sometimes it might be smooth or barely noticeable and then other times it’s worse and very noticeable, all within the same speed interval.
When I say it’s not bad, I could probably live with it. Certainly, other cars I have driven have worse ride quality than this, maybe I’m being picky? But I don’t want to live with it, it’s an S class and I want it to ride like it should.

Anyone have any ideas or input? I forgot to mention, the car is a 2016 S550, two wheel drive, staggered wheel setup. Approximately 79k miles now.

 

Hello from an EMan.
i wonder if your 2 engine mounts are worn?
I don't recall your mentioning mounts beyond the after market transmission one which is an easy fix & switch for an OEM mount.
just a suggestion, as my E Estates over the years from W124 through W210 to my present W212 have had some mount replacements.
Good Diagnosing & Happy New Year!
Jack / Jaxview

 

I don't believe the engine mounts are worn. I have no vibration from the engine, at idle or anything. I can rev the car while idling and it is nice and smooth. I've dealt with bad motor mounts before in other cars, where vibrations are felt from the engine and the vibrations change when shifting from Park to Drive, or engine rocking when you rev it etc.
I also changed the mounts on my 212, although as a preventative maintenance.

 

If the wheels are perfectly round (need to verify), and the rotors are new, then the likely candidate is worn suspension bushings.

If the wheel end of the control arms is stable, but the inner bushing is not, then you will get a bit of vibration at the inner end of the arm, at the worn bushing.

It's worth checking out.

 

The following comments are provided as someone who is very sensitive to vibrations and have always been keenly interested in what causes them. They are just my thoughts which are not those of an expert mechanic.

a) I concur with your comments about the mounts.
b) Next if you aren't feeling it in the steering wheel or pedal box then its likely not the front tires or front end
c) Seems like you have also likely eliminated the rear tires and wheels with the road force balance and inspections.
d) The fact that you feel it in the floor points to the driveline. As you suggest the next stop is inspecting the flex discs and center bearing. It's possible that the driveshaft is out of balance. .
e) I had a problem like this on a 190E. I chased it for ages. I replaced the flex discs and center bearing and even had the rear half shafts rebuilt. One day I mentioned it to an indy and he said he had replaced a number of rear ends on those cars. I sold the car before I found a rear end to replace mine with. The whine you mention could well be the rear end. So if all else fails that is also a possibility

How many miles are on the car?

Is it a 4matic or RWD?

 

Vibration on the highway could be many things, tires (unbalanced? worn? uneven wear? tire pressure?), wheels (bent?), drivetrain (driveshaft, unbalanced?), alignment, etc.

 

Thanks for the insight. I am planning to have the suspension checked by experts.

79K miles and it’s RWD. I hope it’s not the rear end!

Tires and wheels were double checked out to be good. Tires are new, since August and have about 7k miles on them. Tire pressures are all set correctly. At this point, it’s either suspension or driveline related..and hopefully not a rear end.

 

It seems that you have had the tires balanced, I don’t know about others, but o have to get my tire rebalanced every 10,000 miles.

With the mileage, my mind went to motor mounts, I’m at 70k, my service advisor told me that the mounts often go at around 80k 🤷🏻‍♂️

 

I would say out of balance tire or maybe a bent rim.
at that speed its usually a wheel issue

 

I don’t think it’s motor mounts, only because the vibration doesn’t change at all if I shift to neutral and rev the engine while coasting at those speeds. Also doesn’t change while switching gears manually either.

 

Do you think the Hunter Road Force machines wouldn’t have detected that, twice? They had lasers on it and everything.

 

I'd say bent rim. These cars with the fairly low profile tires bend rims all the time depending on where you live, if in the Northeast more than likely bent rim or two.

 

I had a S560 Coupe whos front driveshaft gave way 1000 mmiles from home near Seligman Az. Kept turning till I pulled off the road and beat the heck out of anything near it including the bell housing. I''ve no idea how you'd check it out. Almost untouchable if memory serves. I had vibrations for the previous 100-200 miles prior to it letting go. Expensive, very expensive to repair if not in warranty.

Replaced engine mounts on one CL550 and the S560 Coupe in my life. Vibration was in the steering wheel even at idle. No vibration in the steering wheel with the S560 whos front driveshaft let go. Maybe pay the bucks to have a Mercedes tech take a look at it ?????........expensive for sure.

 

I'm going through the exact same issue right now with 20 inch rims. I got rid of the Goodyear run flats about 2k miles ago and replaced them with the PS4. Although the ride is vastly improved I get those same vibrations at the same speeds. I even get this weird vibration when I'm going into bends on the highway. I have not investigated to the extent that you have but I've been playing with tire pressure with no luck. I was thinking balancing as a first step which would hopefully catch a bent rim. If that does not pan out the next step would be motor mounts. To be honest I've never felt these kinds of vibration and I drove a LS400 with mounts that came apart once I took them off the car. I just has these tires mounted and balanced a month ago and it seems like the vibration has gotten worse. There's no shake in the steering wheel up to 100mph, I feel the vibration more in the gas pedal or the floor of the car as you stated. The car actually rides smooth but the vibration is annoying since I'm moving above 80mph for the majority of my commute.

Sometimes it's there for most of the commute other times it's not. I'm new to MB so I don't know if this is common issue that has a common fix or not. It's def messing with my driving enjoyment

 

FYI a bent rim can be balanced all day long for no gain in ride quality. Balanced or not, the bend in the rim will let you feel it all day long. Balance doesn’t equal round..

Good luck.

 

If it is a bent wheel issue and he is feeling in the floor only (ie not in the front end) then if he swaps wheels from front to back it should change his experience.

 

I hope it's not in the rear end also. My differential whine shows up most prominently when the differential is lightly loaded. I can make it sing and be quiet with the throttle. Mine is also a function of speed at around 50 MPH

 

My understanding is that a Road Force balancing will detect that, since they put a roller onto the wheel as the wheel spins. Any bend or bumps in the tire/wheel will show up. I have staggered wheels so I can’t swap from front to left.

It’s a little annoying to me but I only ever hear it if I have radio off and AC off, with good roads and everything is quiet. I just started searching about this and I guess it isn’t so uncommon. All seem to call for a differential replacement and once the whine happens, there’s no fixing it with fluid changes or anything other than repair/replace. I don’t believe this is related to my vibrations though. Doing more reading across multiple forums and models I’m leaning more towards driveline issues. Some even mention a worn tranny mount will put the driveshaft at an angle that will cause the other parts to be out of alignment. Definitely getting things checked out this week.

 

Road Force is quality and has been around a long time. Capabilities will vary based on machine vintage and version. None are the same.

And more importantly, is the machine operator trained or fresh off the yard. It matters big time.

Search your area for a proven reputable wheel repair shop. Such a shop can tell you the condition of your wheels and in my opinion, you need to know what you are dealing with to find your solution.

Best of luck.

 

I’ve been down the same road with vibration over 70mph.
The problem was a bent rim. Don’t throw money after other theories.
Find a specialty shop for rims. Hopefully the rim is repairable.

 

All other things (tires/rims/worn suspension) considered and sorted, you'll likely find the solution to the 70-80mph vibration in a worn driveshaft center support bushing. I just replaced mine today and much like the bushing on my previous W221 S550 the W222 S550 bushing seems to be good for about 100k miles before the vibrations become unreasonable. What happens is the rubbery bell that the bearing sits in collapses over time and eventually the bearing is sitting on the bottom of the aluminum frame (see photo below). The view in the photo is from the spline end of the universal joint, note how the bearing is sitting toward the bottom of the bushing housing.

The fix is a new bushing/bearing, but it does require removing the exhaust and several heat shields to get to it.

Worn driveshaft center support bushing - 2015 S550 - W222

 

What he just said /\/\.. Also replace the transmission mount, it can cause vibrations >35 mph ...replacing the one on my A207 made the car absolutely quiet and vibration free...Other than that start with checking the rims for out of true either sideways ( lateral ) or vertical ( up down ) The run flat tires are very prone to bending rims...

 

I'm back to report a close to my vibration issue. I'm not the OP so pls don't take this as a thread conclusion. I finally got the time to back to Firestone to get the balance checked since they installed the PS4s last month. No surprise to anyone here but all 4 rims were bent. They must have been bent when I bought the car and since it's my first MB and did not know if the vibration was a characteristic of the car or run flat tires. I knew that this car should not feel like it did on the highway. At times it felt like the lug bolts were loose and the whole car would vibrate. It was worst between 70-85 mph, but I could feel it in all speed ranges. After I left Firestone i contacted a shop in my area and was able to get an appt. this afternoon. After $575 and 2 hours I was back on the road and all vibrations are gone. The only thing I still feel are the 20 inch with low pro tires which I'm used to now even though I don't like it. This is a great car but it annoys me that I've had to buy new tires, get 4 rims straightened, the light is on for the left front speed sensor and I still have to purchase a spare key since the car only came with 1. I didn't think much of it at the time but if I knew a key would cost 700-1000 dollars I would have negotiated the purchase price down further. I'll complain about that in my intro thread though.

 

Glad things worked out for you thanks for the update.

 

Below are the conditions of the flex discs. I couldn’t get to the center bearing since it involves removing quite a bit of parts just to get the heat shield off. Pic just shows the bearing from the edge of the heat shield. Grabbing the driveshaft and shaking it doesn’t feel like there’s any play, however, it was only the transmission end that
I could reach. Ball joints, control arms, suspension parts are all good, so are bearings.
If it’s not the flex discs I’ll have to take the wheels to a wheel shop to have them check for bends.