PiL

Great, thank you. Can you provide details or part numbers for the Benz mounting hardware? I will probably need to share this info with the indy mechanic.

josworth

Not to be a smart @ss but listed in post 1. Upper and lower retainers and the clips.

PiL

As you guys know - over the past week I have been having problems with uneven ride height/collapse of rear passenger side air bag (sometimes in the AM both rear air bags are low). Compressor comes on and levels rear, but sometimes passenger rear is a little lower. Sometimes the unevenness is side to side/tilted (drivers side much higher than passenger side). Took it to dealer last Friday. They re-calibrated air suspension and check bags for leaks - nothing found. It was good for a day and then I heard hissing from the passenger side rear and watched it deflate within a few minutes when washing it. Currently waiting for quote from Indy to convert to coils to avoid future guesswork/repair bills.

Current concern is that we have a road trip planned for tomorrow. Not sure if its OK to travel with the R350 in this condition (it's been fine around town - compressor comes on to lift rear, just titled to one side sometimes). What do you guys think? Will it be fine to take R350 on a 4-5 hour road trip to NJ? What is the worst thing that could happen?

Thanks!

PSH72

Hi

After having my S211 nearly with the rear on the floor ( only have the air bags ), the problem was the compressor that didn´t want to work, only worked when the car arrived at the mechanic, but only 2 min but the air bags didnt lift.

I made the replacement to Arnott coil springs, the height is nearly the same, the driving is better, I think that it was the best thing I did, from now on, no more problems with air springs.

I´m only having one issue, and don´t know if its because I drove the S211 to the mechanic, and the lights went on, now the lights are a bit to low, maybe because the the calibration was made with the rear down, at the instrutions says to unplug the leveling sam module, now it only makes the lights calibration to left and right and does not go down and up, like it used to do.

Is it because before the coils springs have been changed it had the memory of the lights down, and since the module was unpluged off sam it assumes that the truck is still low?

Can I plug again the leveling plug on the sam module, and instead take off the compressor fuse?

josworth

Probably advisable to post into the proper forum. This is the W251 R-Class forum. You will be looking for the proper E Class forum.

PSH72

Im sorry did not see that.

darkflash

Thanks to Josworth and UtahK for the info. I replaced my rear air springs with Mercedes springs (164 324 02 04) and it works perfectly!

Local dealer here in Canada wanted 197.00 + tax for each spring. Found them online in the US for $62.00 on sale! Bought the shim kits, used the single middle width shim and the height is good.

I also used conventional spring compressors as I already own a set, but it was a pain to get it to work properly, lots of fiddling. Not only did I have to unbolt the lower shock mount, but I had to use a pry-bar to get the spring in, and had to massage the spring with a pry-bar to get my spring compressors out. Worked out ok, but would have gone way faster with the center threaded spring compressor.

Thanks again guys for sharing the info, saved me a tonne of cash and the ride is beautiful!

josworth

Congratulations. Glad to see another conversion go well!

GIJOE69

Sorry to revive an old thread!
Thank you guys for the detailed info on conversion!
Just completed 2009 R350 4Matic rear spring conversion
instead of using Jeep & MB OEM coil spring went ahead and used 2009 ML350 4Matic coil spring.

Ordered conversion parts from PelicanParts.com for $285 + shipping
164-324-02-04-M1412 - Bilstein Coil Springs - $51.25x2 = $102.50
164-320-00-56-MBZ - Genuine MBZ OEM Upper Retainer & Shims - $69.75x2 = $139.50
164-325-02-15-MBZ - Genuine MBZ OEM Lower Retainer Spring Case - $11.00x2 = $22.00
211-328-00-58-MBZ - Genuine MBZ OEM Air Bag Clip for Upper Retainer $3.50x6 = $21.00 (Only need 2 but just incase a clip broke ordered extras just to be safe)

Tools used:
Mercedes coil spring compressor [eBay or Amazon about $80-$100]
3 Ton floor jack to raise vehicle via differential
2 Jackstand for rear of car
2 Tire Cholk for front tires
Cheater bar
Plier, Cutter & Pry Bar
Adjustable Cresent Wrench
3/8" & 1/2" Ratchets & extensions
10mm 3/8" 6pt. socket
17mm,19mm & 24mm 1/2" 6pt. sockets
10mm Flare Nut Wrench to disconect air hose from air bag
Plier, Adjustable Crescent Wrench Cutter & Pry Bar
Gorilla Duct Tape [Secure Height Level Sensors arms 90* with Gorilla instead of using Zip Ties]
Zip ties for crimping Air Lines; tape crimp ends with Gorilla Tape

Notes:
Pull & Remove 2-40A Orange Fuses from Engine Compartment Fuse box so Air Compressor will not engage.
Height Level Sensor Mechanism Arm Rod safe to pull & remove from Lower Control Arms attached via 2-10mm nut
Don't waste your time with McPherson monkey bar style spring compressor rental or harbor freight tool

Ride Height Malfuction indicator message did not appear when using Gorilla Duct Tape instead when tried using Zip Ties it did appear for a sec then disappear when going up curbs, potholes or heavy load in the rear.

Joint7

I'm new to MBWorld but I joined so I could get information about my R350. I purchased the car in Oct with only 58k on it. But I almost immediately began having air suspension issues in the rear. My car is not all wheel Airmatic, just the rear leveling suspension with air bags. I knew this problem was possible because I did TONS of research on here before buying the car. So I tried fixing the car once (after the initial drop) by simply replacing an "air suspension bellow". MB dealer did this for me but he did mention the car could drop again. Sure enough, the car did drop again. So I made up my mind to convert rather than pump lots of cash into fixing the issue. I found a local Benz guy that had really great reviews and I just picked up the car today. I printed out the directions from Josworth and Utahkompressor, and I gave those to the mechanic. I paid told him which parts to buy based on what you guys here mentioned. I ended up going with the MB springs from the ML Class, along with the rest of the parts. I also replaced the shocks with Bilsteins at the same time. Drove the car for 45 mins after picking it up today, NO PROBLEMS and it drives great. Just want to thank you guys for giving me the courage to convert rather than spend...! Parts cost me $500 total and the guy did the work for $300 (and that included replacing the housing and bulbs for both of my marker lights). I'm happy!

marasch

Hey, guys! I know this thread is pretty old, but I want you to know that I found it useful. I bought a used R320 for a song, recently, and the pump was dying. I bought a kit to rebuild the pump, but these AMK pumps are a trashy design where they aren't really meant to be rebuilt. Pressing out the electrical rotor shaft busted the piston rod. The bearing came out and couldn't go through the small opening in the rod. I can't get that part and I also noted that the bearings on the pump end of the rotor shaft are shot. Chinese knock-offs of the AMK pumps are $260+.

If the Chinese knock-off is OK, I would still have a system that is bound to have problems again later. I put a lot of miles on my vehicles, and the air suspension looks like a good point of failure to eliminate!

I wanted you to know that I found the 164-324-02-04 springs (-M1412, made by Bilstein) for $51 each. The other parts I found from Factory Mopar Parts. I grabbed ten of the clips, since I might want to experiment with the shims to get the ride height right, so I'll certainly bust a few in the experimentation process. Since these guys only charge about $2 each for the clips. I was thinking I might come up with a model and 3D print a few of my own clips, but at $2/each, it's not worth the trouble.

My total cost is $289.68. Less than $300 for this conversion is pretty good and will help my peace of mind! Thanks, again! I'll report back on how this goes.

Lee Reed

I bought used rear ML350 springs off ebay for less than $100, and paid a guy less than $200 to replace the deflated airbags in the rear. I'd already converted to coil struts in the front, and that cost about $300. For less than $1000, my ride is still really good and I'll never replace another airbag, compressor or control valve again.

seacoaster

Hello Everyone, thank you for all of the great info. I recently complete the conversion to solid rear springs on my 2010 R350. I went with the MB R350 bluetec solids as they were cheap and presumably a proper rating as it is essentially the same. This thread helped a lot in the process.
I am still getting the Malfunction up arrow at all starts, and occasionally get the RED "stop car to low". Any input as to what may be causing this? My mechanic pulled the level sensor arms and ziptied the sensors level(which direction should these move to be displayed as sufficient), as a result, I am not sure if these need to go up or down to satisfy the sensor, they are currently level(3 o'clock). I have pulled the fuse, I have tried both plugging and unplugging the compressor with no change. Oddly, the "stop to low" usually only comes on on the highway, not around town or over things. Any input would be appreciated.
Overall, I think the ride is fine, although the airmatic may have been a bit better, I like the ride height visually in the back, although I have thought of increasing the spacer to see if it changes the feel at all. I went with what the OP had done on this forum.

stu_pidaso

Okay, so here is what I CAN tell you having two W251's and having my share of airmatic challenges. There are two level sensors in the rear, one beneath each bag. Each has three wires going to them, one is 5v the other ground, the last is a variable voltage output that changes as the vehicle body and suspension distances from one another change. The range of the voltage coming from each height sensor is .5v to 4.5v where 2.5v is the center position for S and 2.7v for C (referring to the two height modes selectable via the button by the climate controls.) These changing voltages are fed to a small ECM which is beneath the passenger feet in an area accessable only by removing a fiberglas panel under the carpet. I will attach the wiring diagram for all of this. The ECM is a little larger than a pack of cigarettes. Any measurements should be taken at the ECM from the rear side of the connector as it's simple to access the conductors here. The ride height ECM supplies signals to the air block which meters air going to each bag. The air block has a pair of solenoids which open valves corresponding to each bag you have. As one side of your vehicle rises or lowers and it's not the same as the other side, the ECM knows this and tries to keep a constant voltage coming off the ride height sensors by opening and closing the valves to allow air into the specific bag needing a pressure change and thus a ride height change. If all of the solenoids close, the pressure from the pump climbs and reaches a point that triggers a over-pressure switch mounted on the compressor. The over-pressure switch allows a ground pulse to be sent to the ride height computer as long as the compressor is running properly. When the meter valve block closes all the lines, the pressure rises too high and the ground pulse becomes a continuous ground signal sent to the ride height ECM which in turn shuts off the compressor by un-powering a relay under the hood. If no ground is present on the signal from the pressure switch the compressor won't turn on either.