Adjustable Front Spring
Thread Starter
Senior Member
Joined: Apr 2002
Posts: 405
Likes: 12
From: Sacramento, CA
W204 C300 2010
Adjustable Front Spring
In my quest to get a slightly lowered suspension while retaining the ride, here is my latest solution. What you see here, and probably on no other W210 are polyurethane air spring inserts. After cutting a single coil out of the front, the car settle out to be a little lower than I wanted. After a few phones calls to my old friends at the AirLift company, I was able to find the size of poly air spring that would fit inside of the front coil. The coils on the front have a 3" inside diameter, AirLift makes about 3 sizes that are this diameter, but the 2 of the 3 are way too long. The one I chose was a little short, but I was able to make a spacer out of Delron to compensate for the short bag.
Do not confuse these bags with RideRite or any other Firestone rubber product. This is not a full air suspension. The poly air springs increase spring rate, and ride height is slightly adjustable. The car still rides on metal springs as it was designed. Also they can be installed with disassembly of any of the suspension components.
The first picture is the assembly installed with no air.
The second picture is the poly spring with about 45psi, I had it this way for about 2 weeks and drove it on a 1000 mile plus vacation trip to Los Angeles.
The third picture is the same bag with a 1.25" Delron spacer (very durable plastic material). This allowed a little less air to maintain the same ride height. About 30psi instead of 45psi.
What this whole thing does is really helps when the car hits a sharp bump or pot hole. The air spring soaks up most of the bump and prevents the suspension from going into full compression.
Do not confuse these bags with RideRite or any other Firestone rubber product. This is not a full air suspension. The poly air springs increase spring rate, and ride height is slightly adjustable. The car still rides on metal springs as it was designed. Also they can be installed with disassembly of any of the suspension components.
The first picture is the assembly installed with no air.
The second picture is the poly spring with about 45psi, I had it this way for about 2 weeks and drove it on a 1000 mile plus vacation trip to Los Angeles.
The third picture is the same bag with a 1.25" Delron spacer (very durable plastic material). This allowed a little less air to maintain the same ride height. About 30psi instead of 45psi.
What this whole thing does is really helps when the car hits a sharp bump or pot hole. The air spring soaks up most of the bump and prevents the suspension from going into full compression.
Thread Starter
Senior Member
Joined: Apr 2002
Posts: 405
Likes: 12
From: Sacramento, CA
W204 C300 2010
Yes, it is. It is not much of a performance mod, but the little bumps really get soaked up.
If you have ever rode in a fully "bagged" vehicle, a true air spring has some odd characteristics, when deflatted, it is like riding on a rubber ball. When fully inflated, the ride can be very hard, especially without accumulators.
I did this before on a Fox bodied Mercury Cougar, only then, I went too drastic and I relied for most of the ride to be suspended by the red bag.
For this car, the W210, the stock springs hold a lot of compressed energy, more so than any American car I modified. By matching the poly spring with the MBZ spring, it seems to be a great combination.
Right now, I can only regulate the pressure via a Schrader valve mounted just below the windshield. I am going to keep it this way for about a month, if everything holds ups, I will add some electric valves and a pressure gauge for inside adjustment. Also, I want to get some Koni adjustable shocks to match up with air/spring combo.
If you have ever rode in a fully "bagged" vehicle, a true air spring has some odd characteristics, when deflatted, it is like riding on a rubber ball. When fully inflated, the ride can be very hard, especially without accumulators.
I did this before on a Fox bodied Mercury Cougar, only then, I went too drastic and I relied for most of the ride to be suspended by the red bag.
For this car, the W210, the stock springs hold a lot of compressed energy, more so than any American car I modified. By matching the poly spring with the MBZ spring, it seems to be a great combination.
Right now, I can only regulate the pressure via a Schrader valve mounted just below the windshield. I am going to keep it this way for about a month, if everything holds ups, I will add some electric valves and a pressure gauge for inside adjustment. Also, I want to get some Koni adjustable shocks to match up with air/spring combo.
Thread Starter
Senior Member
Joined: Apr 2002
Posts: 405
Likes: 12
From: Sacramento, CA
W204 C300 2010
Adjustable Front Spring - With Koni Sport shocks
With my front air spring combo, for the last 7 months I have been riding on my stock shocks. I finally replaced them with Koni Sport(yellow) shocks. For the W210, the front and rear shocks have 3 adjustable positions.
Unfortunately, the design of the shock makes it hard to adjust without removing them, especially in the rear. You have to push a little brass button located under the dust shield. For the fronts, I cut or shortened the stock plastic dust shield by 1 1/2". This still allows full dust protection when the car is resting on it's tires, but when I jack the front up, I can now reach in and push the button through the wheel well. You still have to remove the top mounting nut, but you do not have to take the whole shock out to adjust it.
For the rears, I did the same thing, but it requires two people to adjust them because the top of the shock mounting stud is located in the trunk behind the carpet rear panel. One person has to push the button and the other can do the adjustment in the trunk.
As for settings, I initially set them in the middle position. To my amazement, this setting was really stiff. Almost truck like. I just set them back to the lowest or the first position. Now the ride is a little stiffer than stock, but does not vibrate the entire car anymore.
They are a significant improvement over the stock shocks. Even with the front air spring combo, the ride is now more controlled and a little firmer. Almost no nose dive during braking and speed bumps seem to feel more flat.
Unfortunately, the design of the shock makes it hard to adjust without removing them, especially in the rear. You have to push a little brass button located under the dust shield. For the fronts, I cut or shortened the stock plastic dust shield by 1 1/2". This still allows full dust protection when the car is resting on it's tires, but when I jack the front up, I can now reach in and push the button through the wheel well. You still have to remove the top mounting nut, but you do not have to take the whole shock out to adjust it.
For the rears, I did the same thing, but it requires two people to adjust them because the top of the shock mounting stud is located in the trunk behind the carpet rear panel. One person has to push the button and the other can do the adjustment in the trunk.
As for settings, I initially set them in the middle position. To my amazement, this setting was really stiff. Almost truck like. I just set them back to the lowest or the first position. Now the ride is a little stiffer than stock, but does not vibrate the entire car anymore.
They are a significant improvement over the stock shocks. Even with the front air spring combo, the ride is now more controlled and a little firmer. Almost no nose dive during braking and speed bumps seem to feel more flat.
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Joined: Jan 2002
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From: Long island, NY
2012 E350 4matic/97 e320 and 01 ml320
need info
rob, quick questions, exactly how much height adjustment is achievable, how much does it cost with part numbers and how hard is the install? i need about quarter to half inch adjustment. i have 18's, h and r cup kit #1 pads all around, with 19 inch they rub a little event with the mods i did to my fenders. is there a pic of your car?thanks in advanced.
Last edited by topdeez; Apr 16, 2005 at 08:38 PM.
Originally Posted by topdeez
rob, quick questions, exactly how much height adjustment is achievable, how much does it cost with part numbers and how hard is the install? i need about quarter to half inch adjustment. i have 18's, h and r cup kit #1 pads all around, with 19 inch they rub a little event with the mods i did to my fenders. is there a pic of your car?thanks in advanced.

What rims are those?
Sorry to jack!
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Thread Starter
Senior Member
Joined: Apr 2002
Posts: 405
Likes: 12
From: Sacramento, CA
W204 C300 2010
Originally Posted by topdeez
rob, quick questions, exactly how much height adjustment is achievable, how much does it cost with part numbers and how hard is the install? i need about quarter to half inch adjustment. i have 18's, h and r cup kit #1 pads all around, with 19 inch they rub a little event with the mods i did to my fenders. is there a pic of your car?thanks in advanced.

topdeez and all - I will try to get you some side view pics. I am at work right now and I seem to have all the fender/wheel pics on a seperate disk drive at home.
I have been playing around be adding more of the white delrin spacers underneath the red air bladder. Right now the range from low to high is about 30mm or 1 1/4". This is going from 0 to 50psi. Although, at 50psi, the ride is very stiff.
From the looks of you car, it its about an inch lower than mine when it is at it's lowest height.
Installation - This is where it might be worth a try because you do not have to take anything apart. I was able to slip the air spring between two coils with some soapy water. I also sucked all the air out with my suction oil changer first, this allowed the air spring to be very flat and compact.
The AirLift part number is 46149. It is a kit that comes with all mounting hardware.
Hope this helps,
-rob lee



