First of all, I do not subscribe to the idea of dainty suspension on any properly engineered car. A 100k miles, EXCLUDING severe operating conditions, is nothing for an E class. Driving in Ohio, where by American standards roads are “not great, not terrible” is not a severe operating environment — in my estimation.

Two: I know that dampers get out of spec with use, but it’s either fine or quickly it isn’t. There isn’t really an in between condition. Spring do lose some rate, but it’s probably 1-4% over 100k miles (very roughy/approximately). Dampers have hydraulic fluid viscosity change a little, but it isn’t a very significant change, just like with springs. Now, when the damper starts leaking internally or externally, I think it’s a run-away situation, like making a small hole in a damn will quickly lead to its collapse. The damper may be few or several percentage points off original spec due to fluid viscosity change, but once it starts leaking it’ll quickly go from, say, nearly within spec to nearly totally out of spec very rapidly. As in it doesn’t degrade linearly through its life beyond first few percentage points. Makes sense?

So, if the car feels secured and assured at +/- 100 mph on “not great, not terrible” roads with bends, connection joints, etc and there are no extra oscillations, and the tires don’t wear funny, then that means the dampers are nearly in spec compared to new, even at 100k miles.

Suspension links, in those, rubber gets harder with age, so they’ll become a tad more noisy, but again, a few percentage points at best vs new. If the rubber is gone/torn then that’s different, but there will be obvious play in the link in such a case and a noise. I suspect what many feel as new tightness when new links are installed is an effect of retorquing suspension links, meaning retorquing alone of the old links would give 95%+ benefit vs new links (considering rubber is not torn/chewed).

in your case, you may have just been unlucky that your original Sachs units went bad — it happens, and/or the streets of Jakarta (if I’m not wrong that’s where you are from) are a severe operating environment, and since yours is a Sport model, with bigger wheels and smaller tires, your suspension takes more beating.

I am open to any corrections you would like to bring forward, as I’m only curious about truth, so to speak, and not being right.

 

 

I’ve rented on Turo a face-lifted W213 in Los Angeles, where roads are just horrible and found it felt similar to my car, but tauter, just like you describe. It was also quieter over bumps, which I take it more due to a better, more complex front suspension design with twice the number of bushings vs our cars. But otherwise, it was still a rather choppy ride on not good and bad pavement, but the car rode on 19s.

another time I’ve rented, in the same city, a 2022 7 series on 20s with air suspension… nice car, but bad LA roads punched right through the suspension if one is not careful, even in Comfort Plus mode. It creaked audibly near C pillars when entering a driveway, at 35,000 miles.

Next time I’m there, I will try a base 530 on 18 inch wheels.

 

Darwin,
You need to see how dampers internal valving works and do not think a gas damper works because it is using gas pressure as damping medium.
Our damper is hydraulic based damping, the shims acting as "spring" , shims deflect/open like reed valve on 2 stroke engine at a known deflection and hence oil quantity flow.
It is all about oil transfer between 2 chambers, as the damping method and medium.
There is also a main piston o-ring or seal, which can also have a mild leak between chambers, but not to outside of the damper.




http://www.kybweb.com/en/shockabsorber/Structure.html

Don't imagine suspension dampers like a gas strut of our engine bay hood which is a 100% gas.
Imagine our dampers as two chambers for oil to migrate. The migration of oil between these 2 chambers are the damping effect it produces thru resistance of oil flow.
Controlled chamber to chamber leak would be a good way to call its operation.

I am not discussing nitrogen gas leak or oil leak to outside of the damper, but the internal valving leaking between chambers.
Over time these shims and piston main seal get tired and will leak more ( unwanted ) oil between the two chambers and that means damping force also drifts out of spec.
Some dampers can have the valve and seal kit rebuild and designed to be easy to tear down.

Wear and tear on internal valving of a damper is based on friction/movement cycle, so much millions times rubbing up/down or shims deflection and that is distance covered by the car and not bad roads per se.
Bad road will push more movement magnitude on the valves.

The nitrogen pressure is to keep bubbles in check so that oil does not bubble up, as air bubble is compressible where oil is not compressible and air bubbles can give jerky damping.
So when one removed a damper from the car and inspect a damper for oil leak or no auto rebound on its own from nitrogen pressure within, that has nothing to do with the internal valving I speak of.
The only way to measure those internal valves "leak" behaviour is using damper dynometer, spring not measured, just the damper.
If one knows his car well enough, one can feel when the compression and rebound is no more as precise as it used to be or a bit more excessive piston travel,
that is them internal valves are leaking between chambers more than it should.

============
Darwin wrote :
Two: I know that dampers get out of spec with use, but it’s either fine or quickly it isn’t. There isn’t really an in between condition.
So yes there is an in between condition. if you are sensitive enough and has reference to how a very fresh damper behave, you can sense the internal valving is getting "tired" well before any oil or nitrogen leak.
============

Starts at 6:15 , better designed damper for a particular car does reduce road noise.

You Tube

The swish noise the engineer refers to is from orifice flow, the valves body are also an orifice, or passage for oil to flow.
The chuckle can also be from the valves mentioned, among others.

Here is a good information/detail on how shim is part of the oil flow control : https://restackor.com/sample-apps/st.../bleed-systems
Now that you understand how these internal valves will wear out slowly and oil flow volume and speed of its transfer between chambers changes albeit under a same load, that is the aging we can feel.
Our car weight stay the same, and when damping value changes, we can feel it based on the very same road you are very familiar with at the same speed. Speed is inertia, so it has to be the same speed.

=======================================

Now engine mounts : get under you car when you done reading this : https://mbworld.org/forums/e-class-w...ml#post8676779
It is measureable by sight for those who are not able to sense its slowly aging state.
Imagine this : New mount can have travel to absorb vibration, let say 20mm maximum. As mount ages the amount of travel reduced slowly to 15mm....10mm...5mm because the elasticity has reduced by much,
or some rubbers inside it has been smashed/squeezed yada yada.....and then the mount collapsed or touch down to its bottom.
When one said that he can feel much more vibration at idle , that mount is already bye-bye a long time ago as that vibration is so low magnitude at idle and if it goes into the car cabin...well, bad very bad.

Think new engine and tranny mounts like a sofa with 4 inch nice soft foam, vs an aging mounts like a sofa with 2 inch foam and brittle one. You can feel it when you sit on those 2 sofas.

Kickdown from 2nd to 1st gear is the best way to "hear" and feel engine mounts + tranny mounts excessive deflection. 3rd to 2nd gear,,,not so much torque.
The more power/torque the car has, the more lead footed the driver is and lots of kick down between 2nd to 1st gear, the faster the engine mounts and tranny mount get worned out.
Bad roads also accelerate engine mounts wear. Heavy braking also works hard the engine + tranny mount, in pull-out mode.

Tranny mounts is the most easy one to see its aging state, due to its position. It will depress to deeper depth ( shrink more ) given the same load at engine off.
Rubber get harder ( eventually brittle ) as they age, so less comfort over time. Their so called shore hardness or durometer changes with age.
Have a read here , based on tire's rubber compound : https://www.researchgate.net/figure/...fig1_290627653

Engine torque is what destroys engine and tranny mounts, aside from rubber aging and bad roads. Torque is the power to twist.
To engine mount LEFT side it is the compression force, to engine mount on the RIGHT side it is pull-out force.
Our engine is clockwise rotation if seen from the front bumper, or counter clockwise if seen from driver seat.



Your 3.5 NA engine has 370nm, but it develops that torque only at 3,500 RPM.
My 3.0 TT produce 480NM at merely 1,400 RPM and still has that much all the way to 4,000 RPM.
An M278 pumps out brutal 700Nm at 1,800 RPM to 3,500 RPM. This engine and its M157 & M177 more brutal brother will eat thru engine + tranny mounts like breakfast if driver is throttle happy.
Use the gear ratio to multiply the torque.









So when I said your 100,000 miles car will feel much better with simply a new engine + tranny mounts and Bilstein B4 dampers, I am not kidding you.
I am giving you a very expensive tip. , which is the cost of my own education with my E400.

 

Supreme response, meneer! But I would like to make sure we are not missing forrest for the trees:

The valves inside a damper do not rub directly against each other. When the damper operates, the fluid flows through the valves and interacts with these components. The movement of the fluid causes the valves to open and close, regulating the flow of fluid and providing damping characteristics. The primary source of wear in a damper's valving system comes from the repeated cycling of the components and the friction between the fluid and the surfaces of the valving components, rather than direct rubbing between the components themselves. Right? And valving components are metal

So, the amount of wear on the valving components of a damper due to friction between the fluid and surfaces is generally considered to be relatively small or minute over a distance of 100,000 miles — EXCLUDING EXTREEME/SEVERE CASES/OPERATING CONDITIONS, like routinely running over horrible
and terrible potholes, slamming hydraulic fluid into valving components in whole, instantly, and repeatedly — I think it’s a few several percentage points off new spec, ditto for springs, ditto for hydraulic fluid viscosity. If something does go wrong inside a damper, it’ll be a runaway condition, and noticeable to a more or less attentive eye of a car enthusiast.

If the car drives fine and secure at high speed, without extra oscillations, chances are, the damper is not too far of new spec, even at 100k miles, and as seems to be in my case. Mercedes’s suspension is not dainty by design! No doubt, swapping in new spring, dampers, and strut mounts will tighten things up, but we are talking about marginal improvements (~10% at best).

Going to the airport last week, there was am inner city rabbit (sponsor) driving in a Jeep Compass or something at 110+ mph (inner city people in America are like that) on a freeway. Following him, I’ve reached a speed limiter (132 mph on my car) a few times, weaving between cars here and there, going over expansion joints, braking from 130 mph to 75 mph and so on. At 100k mi, my original suspension is still very serviceable, even if not 100% in spec. I believe struts and dampers are the most over-replaced automotive items after engine oil

I will still be digesting your supreme post over the next few days. Thank you for taking the time to share the product of your cognitive superpower (mean that sincerely!)

 

Darwin wrote :
The valves inside a damper do not rub directly against each other.


The piston seal is forever rubbing its polymer seal material against damper metal body-tube when damper has movement, can't you see that ?
Without the polymer seal of the piston, oil will transfer with ease between top and bottom chambers. Also damper inner tube will scored bad without piston seal as friction
sacrificial unit.



Let me give a better illustration of the unwanted leak between the chambers, caused by the piston seal when it wears out.
No 2 in brown is the polymer seal. This piston is moving up-down all the time, so polymer seal is scrubbing all the time.

COMPRESSION MODE



REBOUND MODE



Darwin wrote :
When the damper operates, the fluid flows through the valves and interacts with these components. The movement of the fluid causes the valves to open and close, regulating the flow of fluid and providing damping characteristics. The primary source of wear in a damper's valving system comes from the repeated cycling of the components and the friction between the fluid and the surfaces of the valving components, rather than direct rubbing between the components themselves. Right? And valving components are metal

Here you got confused between shims and polymer seal of the piston.
Here is what is happening for the shims, which I believe you call them VALVES.
The piston as shown has 2 sets of shims kit, one is for compression and one is for rebound. Simply put, 1 set of shims control oil flow from top of chamber to bottom of chamber, this is the
compression shims kit. The other set of shims is controlling the flow of oil between bottom to top chamber, this is the rebound shims.
These shims control oil flow by itself getting deflected or bending OPEN, that is why I initially said reed valve of a 2 stroke engine as an example.
These shims are not like a washer for bolt and nut, these shims are spring shims, the metal is made from spring steel.
The shims do not cover 100% of the oil path, some only as there are pre-measured "leak" from those uncovered oil path inside the piston.

Light grey is the polymer seal material of the piston, them oil passages some are to be "sealed" by shims, some are pre-measured leak on purpose.



This video shows a thin blade, that is a reed valve. It open and close by deflection. Same as the shims in a damper, it also deflects when OPENing for oil to flow.


Every metal with springy-ness built into it, will fatigue or loose its springy-ness overtime and some will break, example MB coil spring do break .
Ever break thin metal sheets by bending it over and over ? Yes, it will break. In case of spring, it may not return to its zero state.
Imagine leaf spring from an old pick up truck, same working principle. Damper shims are round and leaft spring are long springy metal bars, that's all the difference.
Have you ever seen old 1984-87 Honda Civic "coil" spring equivalent ? It does not use coil spring or leaf spring, it uses torsion bar as spring.
Twisting motion instead of coiling motion. Like how our sway bar works.
Do these springy stuff get fatigued ? Of course.

==============================


Here is an illustration, of a hydraulic ram and not shock absorber but it has the piston seal too.
Hydraulic ram does not want any leak at all between the top and bottom chambers, hence no holes inside the piston and no need shims stack too.
Example, a garage jack which slowly sinks down under pressure, but no physical oil leak to its outside body, that is that piston seal leak between chambers.



Here is a nice see thru example of mono and twin tube shock absorbers






Now the dynometer chart. Look at the right side image.



Our damper does not work to replace a spring, it is there to dampen the forces of the spring when working in a suspension system.
If you see the compression zone is Lbs/Pound, it is ony 50% value of re-bound.
When in compression mode, the spring offers X kg per millimeter of compression, so damper is there to smooth things out.
Well , sport damper can make car more firm by resisting spring compression by that oil flow resistance tuning.
Basically at compression, springs take the load.

Now the re-bound section is a lot more work but for the damper, the damper must fight the spring re-bound and car weight itself having momentum* ( *jumping over hilly bump or fast tight S bend ),
hence it shows 1,200 lbs and instead of the 600 lbs of compression. Here is where you can easier sense your damper aging, the rebound action does not feel right.
Taking tight S bend fast will also show if damper rebound is poor, the massive weight shift between left to right and vice versa on an S bend if rebound is too fast due to piston seal leaking,
you loose traction on that wheel as less weight exerted on the tire and hence traction also reduced.

To the right side of the chart is velocity. Damper is a velocity device too, the faster you push it down or pull up, the more resistance/damping it will provide.
It is simple hydraulic, push more fluid using the same hole/orifice/opening, you need more pressure because of higher resistance from more of the fluids fighting for the same passage.

Damper take motion energy and converted it to heat, the damper oil then gets hotter and it breakdown too....yep.
Offroad dampers have very big secondary stand alone oil revervoir with a hose, so that it can cool the oil better by having more oil and surface area and is made from aluminum,
a better heat radiator compared to steel.

My friend uses King dampers for his 4WD Toyota, sometimes I helped him rebuild it and it is designed to be rebuild over and over. Per 3 years or 40,000KM it would be rebuild.
This is how damper oil looks like after X mileage of use :


1 is piston polymer seal. 2 is the piston complete with shims stack. 3 is the greyish dirty oil.
4 is the outer and inner seal for shaft of piston to not leak oil to outside of the damper body and for oil not to leak out from damper tube to outside.



Above is an upside down mounted damper. Its piston shaft orientation is downward, not like our damper which its piston shaft orientation is upward to the sky.

Can the owner , my friend feel his damper no more "nice" ? .....hell yeah.
No oil leak on the floor and no nitrogen pressure loss, simply internal shims & piston-seal wear and tear or fatigue.
First to go usually is the piston seal, simply from the nature of its duty rubbing against damper inner metal tube. Shims last a long time.

 

@4rvrDarwin soooooo

After you replaced shocks and struts on your 2015, you ready to revisit this?

 

You openly admit a few significant differences in your comparisons, two of which seem pretty glaring, regardless of how much you continue to try to defend one as being a non-issue.

1) Roads. It is impossible to compare the ride and NVH, when one vehicle is driven on the roads you describe in Ohio, where all four seasons are a factor, and the other vehicle is driven in Florida, where roads never experience heaving and freezing and salt.

2) It's great that you inspect your suspension regularly, and find no visible signs of wear. But your statements totally ignore that the E350, with 100k miles, has had went through 4X the number of cycles that your brother's M550, with 24k miles. And, considering item 1), those suspension cycles in Ohio are much more severe than those in Florida. Would it be reasonable to suggest that your E350 has been through the equivalent of 200k miles on Florida roads? Your claim that your car is in "mint" condition suggests that you think, when the time comes for new suspension components, that the change, from "mint" condition to in need of repair, happens overnight? I would suspect you actually know better than that.

At 100k hard Ohio miles, you need to be putting new struts and shocks on your car. Perhaps even new motor mounts and transmission mount. Then, take a drive down to Florida, and compare it to your brother's BMW.

It seems extremely disingenuous for you to even suggest that it is a fair comparison of your 100k mile car to your brother's 24k mile car, each having been driven in different conditions. A lot of sound explanations have been offered here, but you continue to ignore them, claiming that your E350 is in "mint" condition, so it really doesn't feel like you are looking for anything other than other's to validate your claim. Sorry you haven't gotten your validation.

 

Can anyone else with a late model W212 E350 luxury with low miles weigh in on the ride quality?

 

No, but I have a 2011 whose ride has deteriorated over the past couple years pretty obviously because it needs front struts. I'll report back next week after I get them done. Did shocks in the back last week and it's already a huge improvement.

These cars have a superior suspension setup. The only issues are wear items (like shocks/struts, maybe bushings) and the subframe stuff in the back, but of course there's a recall for that now.

 

How many miles?

 

I'm going through the very same thing! I have also replaced the rear shocks, and am waiting to replace for a good window, to replace the front struts. My '14 E350 has about 94k miles, and on a recent road trip, my wife commented that the ride wasn't as good as it used to be. Except for very minor evidence of wetting on one of the front struts, inspection shows nothing wrong with the suspension, so it surprised me when I could tell the difference from just replacing the rear shocks.

Are you putting genuine MB parts on? I didn't previously mention my replacements, as I am replacing with Bilstein B4 struts/shocks. I'm looking forward to compare your experience to mine, after you complete the front end.

 

@Bhopkins As far as I can tell, the Luxury and Avantgarde (aka Luxury but lowered) suspensions have the same shocks. The spring rates might be different.

I have a wagon, so I wanted to do the heavy duty Bilsteins in the back, but there is a nationwide backorder. So, I just replaced with stock Sachs which are VERY soft. Arnott air springs back there, which obviously hold up the weight.

I bought B4 struts for the front and will reuse springs; Sachs bearings. I imagine it will be a bit stiffer than stock based on the limited sample size of my Saab 9-3.

 

How did the new Sachs shocks feel compared to the old? Have you driven it after the shock replacement?

 

I will weigh in here on the 'do shocks/struts wear with age/mileage' question:

The car is a 2014 E350 Sport (18" AMG wheels). When new, the car ride was never 'Cadillac smooth' (floaty), but rather was composed and controlled no matter the size of the road imperfection, and whether that imperfection was mid-corner or over a rise.

Over time, the ride did start to become more 'floaty' (some feel that this is more 'luxurious') as the shocks/struts wore.

At around 90k miles, I noticed that the rear was bottoming out (hitting the bump stops) on roads where it had never bottomed out before, and the front tended to 'wander' very slightly - as if from a cross-wind. Coming from a motorsports background, and favoring fidelity of control over 'experience', I decided it was time to make a change.

Replaced shocks/struts with Bilstein B4s, as well as replacing all mounting hardware front & back.

Ride is back to 'original' (definitely firmer than with the old shocks, definitely more controlled body movement), and no longer bottoms over the same roads under the same conditions (passenger load/speed).

Smaller imperfections are now somewhat felt (were originally masked by 'floaty' shocks), but larger imperfections are handled with composure/control (caused bottoming and harsh impact on 'floaty' shocks).

Debates can be made about shock wear, rate of wear, etc.

In my experience, replacing the shocks returned the ride to it was when the car was new - so I'm happy. Maybe this helps some, maybe it doesn't. Happy Motoring!

 

This report makes perfect sense.