W211 airmatic suspension calibration
12-11-2022, 04:47 PM
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'99 and '05 E55 AMG
W211 airmatic suspension calibration
BLUF*: Whenever components of the front suspension (or rear) are replaced, confirm the vehicle level and, if necessary, recalibrate the air suspension.
I replaced all front suspension components (thrust arms, control arms, ball joints) on my W211 at 200,000 miles (car now has 222,000 miles). The front seemed to sit a little lower but I ignored it as I have calibrated the suspension in the past. (My bad for being lazy and not verifying again until now.) I was getting undue tire wear (both tires' inside edges) so decided to check the Airmatic Values.
-First, go to "Control Modules/chassis/suspension/vehicle level". Acceptable factory parameters (Front left / front right / rear) -3 to +3mm readout of the vehicle level values. Mine were -17 / -17 / -11. Yikes!
-Second, go to "Control Modules/chassis/suspension/Initial Actuation/Initial Actuation with manual input of values". Acceptable front values are +3.1 to +4.1 degrees. Both front control arms measured -2.7 degrees. (Yes, the car was a bit low in the front.)
-Third, adjust the ride height per STAR instructions. I raised the front so both control arms measured +3.2 degrees. This raised the front fender rolls from 25.75" to 27". Adjusting one side will affect the other so obtaining the proper settings involved a bit of back-and-forth. I measured the inclination angles using an Inclinometer app on my cell phone. Rear then measured within acceptable range (-0.9 to -1.5 degrees; both of my rear axles measured at -1.2 degrees) so I left it alone.
-Fourth, go back to the "vehicle" level page. Mine now showed as +2 / -3 / 0. Correcting the issues in the front resolved the issue with the rear.
Car now rides better, a slight "tug" to one side disappeared, and the toe verification showed each tire as -1mm toe-in. I spent an hour recalibrating the ride height and maybe another hour setting up my alignment apparatus and verifying measurements. Well worth my time. Don't forget to ensure the floor is absolutely level under the car's tires. FWIW, I needed two floor tiles under the front left tire and one floor tile under the left rear tire. I used two identical sockets (each socket where a tire would sit), a 57" (145 cm) length of 1" square aluminum tubing laid across the sockets, and the inclinometer app. Add floor tiles as needed to obtain a level surface.
*BLUF - Bottom Line Up Front. The first sentence to your boss should encapsulate everything he/she needs to know. If the boss wants more info, he can ask for more detail or read the rest of the briefing.
I replaced all front suspension components (thrust arms, control arms, ball joints) on my W211 at 200,000 miles (car now has 222,000 miles). The front seemed to sit a little lower but I ignored it as I have calibrated the suspension in the past. (My bad for being lazy and not verifying again until now.) I was getting undue tire wear (both tires' inside edges) so decided to check the Airmatic Values.
-First, go to "Control Modules/chassis/suspension/vehicle level". Acceptable factory parameters (Front left / front right / rear) -3 to +3mm readout of the vehicle level values. Mine were -17 / -17 / -11. Yikes!
-Second, go to "Control Modules/chassis/suspension/Initial Actuation/Initial Actuation with manual input of values". Acceptable front values are +3.1 to +4.1 degrees. Both front control arms measured -2.7 degrees. (Yes, the car was a bit low in the front.)
-Third, adjust the ride height per STAR instructions. I raised the front so both control arms measured +3.2 degrees. This raised the front fender rolls from 25.75" to 27". Adjusting one side will affect the other so obtaining the proper settings involved a bit of back-and-forth. I measured the inclination angles using an Inclinometer app on my cell phone. Rear then measured within acceptable range (-0.9 to -1.5 degrees; both of my rear axles measured at -1.2 degrees) so I left it alone.
-Fourth, go back to the "vehicle" level page. Mine now showed as +2 / -3 / 0. Correcting the issues in the front resolved the issue with the rear.
Car now rides better, a slight "tug" to one side disappeared, and the toe verification showed each tire as -1mm toe-in. I spent an hour recalibrating the ride height and maybe another hour setting up my alignment apparatus and verifying measurements. Well worth my time. Don't forget to ensure the floor is absolutely level under the car's tires. FWIW, I needed two floor tiles under the front left tire and one floor tile under the left rear tire. I used two identical sockets (each socket where a tire would sit), a 57" (145 cm) length of 1" square aluminum tubing laid across the sockets, and the inclinometer app. Add floor tiles as needed to obtain a level surface.
*BLUF - Bottom Line Up Front. The first sentence to your boss should encapsulate everything he/she needs to know. If the boss wants more info, he can ask for more detail or read the rest of the briefing.
Last edited by bbirdwell; 12-11-2022 at 04:51 PM.
