[deltz]

I've been searching around for a while and haven't really found anything on how good/bad the self leveling is once its working compared to normal shocks? Some said its the same, some say much better.

How good is it for speed road humps, or is it just mainly for motorways?
Are they worth the extra price on repairs over shocks?

 

[Brett San Diego]

That's a pretty good question. I've never ridden in a W140 without the self-levelling suspension. If I were to guess, I don't believe that the hydro-pneumatic self-levelling suspension is as smooth a suspension as simple spring and shock.

Brett

 

[tackleberry]

Ill chime in here. My car has regular shocks. My crown Vic had regular shocks. My first crown Vic.had air suspension.

Yes, it is worth it ... if you are willing to pay for it. Not to insult the ride of my w140 but if it feels this good without it one can only wonder what its like with it. And having 2 of the same cars one with and one without I can say it does mean a better ride.

 

[lcmlee]

It's amazing.

 

[drcharlesatlas]

"The Andrew" on the forum will be able to tell you because he removed the SLS components on a '93 S500 and replaced with air shocks. He said that the air shock ride was as good if not better than the SLS.
One thing for sure is that maintaining a SLS is can be very, very expensive.

 

[tackleberry]

One thing for sure is that maintaining a SLS it is very, very expensive.

FIXED!

That right there is the number one reason i dont want an SLS car. suspension components are expensive and most people, including myself, are not on top of suspension work when compared to fluid changes and other things because people figure if its not making noise, shaking, they dont bother with it until it really goes bad. on my crown vic each airbag was over $250-300 bucks each side. to fix the entire system, with all sensors looking well over $2000 with labor and thats on ford panther platform (low labor hours on most things and low parts cost) you are looking close to triple that on a mercedes or any european car. (assuming worst case scenario for parts)

i personally want new shocks in my car just because it deserves it, and for the price of them they are not really a whole lot of money for a fix that will do nothing more than increase my ride quality, general handling and enjoyment of such a fine luxury car.

 

[Brett San Diego]

Ill chime in here. My car has regular shocks. My crown Vic had regular shocks. My first crown Vic.had air suspension.

Yes, it is worth it ... if you are willing to pay for it. Not to insult the ride of my w140 but if it feels this good without it one can only wonder what its like with it. And having 2 of the same cars one with and one without I can say it does mean a better ride.

The W140's self-levelling suspension is not an "air suspension." It is typically called hydropneumatic (hybrid of air and hydraulic). It does not have rubber air-bladder style air springs, but rather steel "accumulators" with a rubber diaphragm that separates a volume of nitrogen from the hydraulic fluid.

Brett

 

[SoCal_Dan]

Since regular SLS doesnt have ADS, I would imagine the ride would only have a slight advantage over regular shocks and thats assuming your whole SLS system is 100% working.

Considering most 140's with SLS nowadays have been neglected(or rather I should say the accumulators), then ride quality is probably on par if not worse than regular shocks.

I'm probably one of very very few people on this board who supports SLS. I refuse to remove the system and have a half ass S500 all for the sake of "saving money". Dont get me wrong, I'd like my 140 maintenance to be as cheap/affordable as possible, but not at the expense of removing components to justify ownership.

I also hate regular shocks for that sagging rear end look, with or without passengers/trunk luggage. My car is not a lowrider, so it should be perfectly leveled front and rear.

Sure, you can switch to regular shocks and lower the car to avoid the lowrider look, that is until you have passengers and trunk cargo and the rear end starts bottoming out on bumps. Been there, done that with my W202.

Besides, my SLS system functions just fine so I have no reason to remove it. Even if something goes wrong, I'm perfectly fine with buying a $650 shock. Beats the price W220/W221 owners pay for with their air suspension shocks

 

[tackleberry]

The W140's self-levelling suspension is not an "air suspension." It is typically called hydropneumatic (hybrid of air and hydraulic). It does not have rubber air-bladder style air springs, but rather steel "accumulators" with a rubber diaphragm that separates a volume of nitrogen from the hydraulic fluid.

Brett

that i am aware of, but just comparing my experiences with a traditional setup compared to an advanced setup in comparison to traditional.

i know the lincoln mark 8 i think, in its last years made had 4 wheel either form of SLS or 4 airbags one for each wheel which is why you see a lot of them bottomed out front and rear driving around.

the air ride in the panther is self leveling tho as i filled the trunk to capacity and it was the same ride height as it was empty. again i fully know i am comparing a ford system to a much more advanced mercedes system but im just stating the difference in ride quality on 2 identical cars one with one without for the OP's general question.
i did notice that going over bumps and such and freeway ride the air system i had was like riding on a cloud, where my panther with traditional setup was choppy and more harsh. (again, cheap american car but you get the idea lol)

 

[lcmlee]

the ride quality of SLS should be similar to regular shocks. The difference is when you load up the rear end of a W140 with SLS, it will level itself, whereas regular shocks will not.

When filling up at the gas station when the W140 is near empty, you can see and feel the W140 self level as gas is filling up the tank. I especially like it when I buy a few hundred pounds of top soil and load it into the trunk and the W140 remains level. Try doing that with your regular or air shocks.

 

[nhzruthless818]

i have owned both with sls and without. ride quality was about the same except when you have more people in the car and have sls it would feel the same as if no one is in the car.

 

[lcmlee]

i have owned both with sls and without. ride quality was about the same except when you have more people in the car and have sls it would feel the same as if no one is in the car.

...and that is where the difference is...when you load the car up when it has SLS, the ride quality will stay the same. That is the mark of a true W140, the ride quality with anybody in the car, handling stays the same at any speed, etc. No other car will compare.

 

[iss]

Here is mine!!! And oh yeah!!! I LIKE IT!!!

 

[MafiaDON]

My S320 had SLS from factory, but due to all the broken hydraulic components, I opted to to just swap out to normal shocks and springs.. Ride feels right like a Benz should be..

My S500 has perfect working SLS.. I have to say I cant notice the difference between the two.

I guess the main difference between the two systems would be best appreciated when the hydraulic components become broken and its time to fork out truck loads of cash for repairs just to get the ride quality back to "normal"

just my 2 cents lol..

 

[lcmlee]

My S320 had SLS from factory, but due to all the broken hydraulic components, I opted to to just swap out to normal shocks and springs.. Ride feels right like a Benz should be..

My S500 has perfect working SLS.. I have to say I cant notice the difference between the two.

I guess the main difference between the two systems would be best appreciated when the hydraulic components become broken and its time to fork out truck loads of cash for repairs just to get the ride quality back to "normal"

just my 2 cents lol..

Do this test. Load both cars with 500 ibs of sand bags in the trunk and drive over some speed bumps at 30mph. Come back and tell me that you don't feel any difference.

 

[MafiaDON]

Do this test. Load both cars with 500 ibs of sand bags in the trunk and drive over some speed bumps at 30mph. Come back and tell me that you don't feel any difference.

Lol..

I take all my speed bumps at a very slow speed anyway, so this test would not work for me comrade lol..

I usually travel alone with no goods in the trunk. At most I get an additional passenger in the front seat from time to time.. So who would the SLS really benefit?

For me, I'm happy my daily driver has normal Bilsten shocks and OEM normal springs. If I was buying the car brand new, I would leave this option off the list of extras to be installed.

 

[SaleenS7]

The real question should be how many owners are willing to fix their SLS when it does need to be replaced? I know as enthusiasts we can find cheaper parts and good repair shops to do it but I'm willing to bet somwhere around 70% of W140 owners with SLS won't be able to afford repairs.


I've driven a S500 and S600 with the self leveling suspension and in my experience the difference in ride quality with a non SLS model is surprisingly hard to notice. If I was driving with heavy things in the trunk and a car loaded with passengers I'm sure I would have felt a difference. I rarely ever have passengers and I never put anything heavy into my car (except the new rims I bought recently) The Self leveling doesn't benefit people like me or comrade MafiaDON.

 

[The andrew]

I needed two rear struts from the nitro spheres being neglected before the previous owner. The spheres were new MERCEDES parts when I got the car BTW. The only Issue was that the bottom joints on the struts failed. there was no leaks, no issues otherwise. The vehicle rode very well, except for clunking over sharp imperfections.

I opted for looping the hydraulics, replacing the springs and fitting standard Bilstein High Pressure (HD = High Druck, not Heavy Duty) Shocks, and called it a day.

Car rode the same if not BETTER, MORE compliant over large imperfections.
SLS Has short compression stroke travel. SLS was and afterthought, an option, consider that.

This past summer I had 5 decent bodies in the trunk, I mean car, and we were on the way to see the Philharmonic at the State Park on the south side of Long Island.
Boot was full of coolers, folding chairs etc. We were easily grossing over 6000 pounds, bodies or people and gear.

Without the SLS the car dropped about 2 inches from original ride height and maybe 1.5 inches in front. Car looked good actually. The Southern State parkway is a road built in the 50s, paneled concrete, sagging slabs, not the best road.

The car ate. it. up. Actually it felt more surefooted, and the engine kept up with the heft. Torque.

Yeah the car sagged, naturally, but it was controlled.

I like the standard suspension setup. It's more controlled, more compliant, and a little less floaty over/through dips and weaves.

There you have it.

I was nervous I'd hate the ride after the conversion, but the car feels more organic in a way. Compliant and smooth, controlled and planted.


It's really up to giving a crap about having the car loaded like a truck, or not. My car sees few crowds like that of the Philharmonic trip. Mostly it's just me in the car.



Regarding ASD or ADS, that's a different story.


I am VERY picky about ride, takes a lot R&D to get a good, solid, stable ride all at once. The W140 TO THIS DAY makes me smile and marvel at it's ride. I realize How spoiled I am when I hop in the BMW or most other vehicles.

 

[nowhereman]

I must say this is a little disappointing, to hear that the hydro-pneumatic additions don't make a big difference. MB licenced the technology from Citroen when their air suspension development hid too many snags. It does appear to be an afterthought, understandable if it was a last minute solution.

Having owned a number of full hydraulic Citroens I can only say that the ride of a properly maintained one is sublime. And, if properly maintained, incredibly reliable. Salted roads don't do much for the seals, but if fixed at the first sign of leakage few other things will go wrong. Abused or neglected and it will punish you big time.

In the 90's Citroen started to use electronics to create an active suspension system that gave the best of both worlds, taught handling and a limo like ride. For those interested the following youtube clips explain it well. The XM is one of my favourite cars, but very rare.

XM Slalom

XM Road test

 

[nhzruthless818]

the most common issue with our self leveling suspension is the accumulators fail and also the shock mount. that is about it unless your whole shock is done then it won't be cheap.

at my cousin's shop there was a w140 that was in for a full w140 sls replacement service(oem sls shocks, accumulators, springs, mounts, and shims) about $3,000 but if you want to restore or keep it then its worth it.

the sls is perfect if you use the w140 to take your whole family places(rear doesn't sag with a full trunk and 3 people in the back seat and two upfront.) this when the sls shines