Buelligan

EDIT: FIXED! See post #8 for details.

It finally happened. Went out to the E500 (2005) and the front driver's side was resting on the stops. Only 52,000 miles.

I've searched the forums and found out what I need to do (Arnott) and I plan on installing it myself. There seems to be more than one way to do this, but if anyone could offer me a heads up on avoiding any difficulties and what else to check while I'm in there, it would be much appreciated. Before I start turning wrenches, I'll double check the procedures but it always helps to get advice.

If the forum would be better served by me posting this on an existing thread, would someone please post a link to the best one? There are more than a few!

Also, has MB offered any support for owners who've had an issue with their Airmatic suspensions? The car has been out of warranty for some time now. Of course, every problem I've had with it has occurred since then.

I can't tell you guys how much this forum has helped me already. It's reassuring to know I am not the only owner dealing with these ridiculous issues.

Thanks, gentlemen.

Buelligan

Oh, another thing! Is anyone aware of an active promo code I could use for a discount from Arnott?

EDIT: Got the promo code. Got $70 off the list price... this is getting better already.

kompression

Only replace them in pairs. I got both fronts for 750.
Took me 45 min to replace each and the ride quality is much better.
And trust me I've road test them plenty
They are simply superior to the stock which were built to fail.
Another MB dealer side deal Im sure.

Michael.Sinz

I would recommend you do both sides as you will likely notice a difference between the old one and the new Arnott rebuilt one. I just had to do this a few weeks ago. :-(

LILBENZ230

Mercedes will not help. Suspension components are wear and tear, and even though only 52000 miles - 9 years is a lot of time. But pleased it is working out for you, and pleased that I do not have airmatic.

J Dubya

Something I did in hopes to extend the systems life was, replace the pumps filter.

I would assume the cleaner the air, the less likely contaminants would clog the system, overheat the pump and cause a domino effect.

Buelligan

Success! It was mercifully easy... I'll provide more details when I get to my computer (infernal phone!)

No problems at all. Didn't have to let air out of the shock and didn't have to buy or borrow a ball joint separator. I did it using just the stock jack on one side and it was no trouble getting the shock installed.

Thank you, MBworld!

Buelligan

I was able to install the Arnott replacement shock fairly easily without depressurizing it. No wrestling with the lower shock mount or levering the control arm down and no special tools needed, just the usual assortment of metric wrenches and sockets and one Torx driver. I’m not going to outline everything I did, just the two parts that differed from the procedure Arnott recommends.

If you’ve done some research on the forum, you’ll see there is more than one way to remove and install a front Airmatic shock on a W211, but the way I did it has to be the easiest way possible. The procedure outlined by Arnott recommends using a lift to raise the car and using a ball joint separator to unfasten the upper part of the spindle. There are very good reasons for this; a lift is much safer than the factory supplied floor jack and I suspect that using a ball joint separator instead of removing the three nuts and bolts that fasten the ball joint to the upper A-arm guarantees there will be no change in alignment after reassembly. However… not everyone has access to a lift in their garage (or driveway) and the slop in the mounting holes for the ball joint is very slight and will not affect alignment to an appreciable degree.

Because I was replacing the left front shock, I turned the steering wheel all the way to the right before I used the factory jack to raise the car. This gets the spindle (and brake rotor) out of the way and gives you more room to access the shock. Make sure to put chocks on the front tire opposite the side you’re working on and make sure the emergency brake is on – this should go without saying, but I’ll say it anyway. After removing the inner fender and unplugging the wires at the bottom of the shock (this was actually the hardest part of the job for me) I unbolted the three 13mm nuts holding the ball joint to the upper A-arm. I don’t have a ball joint separator like the one in the Arnott installation video (on their excellent website) so this was my only option. With the spindle turned all the way to the right you’ll find it interferes with the rearmost Torx head bolt holding the ball joint housing to the A-arm. If you remove the front and middle fasteners first, you’ll find you can loosen the rearmost nut enough to let the ball joint housing rotate out of the way so you can get a Torx driver on the bottom of the last bolt. Once this is done, the spindle separates from the upper control arm and gives you room to remove the shock. The pneumatic line comes off easily (10mm) and the three nuts holding the top (13mm) come off easily, but if you don’t have a 21mm wrench or 21mm deep well socket to remove the nut on the lower shock mount, a 13/16 spark plug socket works perfectly. If Mercedes didn’t do this on purpose, it was one hell of a happy coincidence.

The old deflated shock was easy to get out, but the new one is pressurized and too long to easily get the bottom mount lined up. This seems to be the sticking point for a lot of people and I was really worried about this part, but it turned out to be a total non-issue. Some forum members have recommended letting air out of the shock by hooking up the electrical connection and levering the control arm down, but I didn’t have to do either of these things. All I did was raise the jack up a few more inches and the bottom mount slipped right on with the shock fully pressurized. The sway bar is what keeps the control arm from freely moving down, but raising the jack (just on one side) will lift the entire front end of the car enough to let the control arm drop and get the bottom shock mount lined up with just hand pressure. Be very careful raising the car with the floor jack. Do it slowly and make sure the front tire on the opposite side doesn’t start rolling. With the tires turned all the way to the right, I could see the car crabbing sideways and falling off the jack so make sure you’re on level ground and the opposite side front tire is chocked front and rear.

After getting the bottom shock mount fastened, the lower control arm will be too low to easily let the ball joint housing connect to the upper A-arm. I got around this by putting a scissors jack under the lower control arm where it bolts to the shock and lowering the car onto it with a few turns of the factory supplied floor jack. This will compress the shock enough to let you easily reinstall the ball joint fasteners. Once you get the nuts tightened enough, that one bolt the spindle interferes with won’t need to be held with a Torx driver - friction should hold it so you can torque the nut to spec. If you can’t get it tight, then just leave it loose and torque it down after you safely get the wheels pointed straight ahead. Don’t try to straighten the wheels with the car on the floor jack; it’s not safe to be moving the steering wheel. Fortunately for me, friction was able to hold that last bolt enough to get it torqued so I didn’t have to put the tire back on and lower the car just to get the wheels pointed straight.

I can’t believe I was able to do all this with just the floor jack and a few hand tools. I didn’t have to lever or wrestle the shock back on, I didn’t have to let any airout, and I didn’t need that nifty factory ball joint separator shown in the Arnott video. The hardest part was actually taking the inner fender off and disconnecting the wires at thebottom. It took me a while to figure it out, but I was able to do it without breaking anything.

After getting everything buttoned up and starting the car,the front end came back up to ride height and there were no trouble codes or warnings and the car steers and tracks perfectly. All is well! In retrospect, the only thing I would have done differently was disconnecting the battery. Arnott recommends this and I certainly see why it would be a good idea, but it didn’t create any problems leaving it connected… this time, at least.

I can assure you this is something anyone who is reasonably mechanically inclined can do in their garage in just an hour (or two). Total cost after I get my core charge back from Arnott will be $416. This is just a little over what a quality coil over shock costs and it comes with a lifetime warranty. I almost can’t wait to do the other side… which is going to be easy peasy now. What I really can’t wait to do is call the local dealer to see what they would have charged. That’s always good for a laugh.

Thanks again to the collective. I would have never attempted this without the aid of the forum. This place truly rocks!

If anyone needs clarification on what I posted, please feel free to ask.

Michael.Sinz

Thanks for that great description. I think I would have gone and borrowed a ball joint tool but it is nice to see that you can do it without. What a savings as local guys say 2.5 hours of book time which means 2.5 x $100/hour (x2 if you do both sides).

PS - If you go to a dealer, the factory strut is $1495 plus dealer install rates of $155/hour.

Buelligan

That would have been my first choice. It's always better to do a job with the right tools, but I don't know anyone who has the ball joint tool and the local parts stores that rent tools just have a blank look when you say "Mercedes."

I just dropped off the worn out shock to the UPS store in the original Arnott box. Arnott pays the return shipping, so it was a snap. I gotta say this experience really shined a good light on Arnott. They were very helpful when I ordered the shock and actually pointed me towards a way to get a significant discount off the list price. It went from $479.87 plus shipping to $416 total with an active discount code that I found on the internet. What a great place to do business with.

I am so pleased! This was win/win... WIN!

Buelligan

I also have a theory about why the Airmatic may have failed and a proposition on how we may be able to extend the service life of the front Airmatic shocks. I'll post my thoughts on this later after I do a little more research. I'd love to hear anyone elses theories.

WEBSRFR

Thanks so much for sharing this information with us! I also have Airmatic shocks in my E550 and I dread the day they fall. Like your car mine only has about 50K miles but it is now about 7-8 years old. I have a great independent shop nearby but if the shocks fail if I am further away from the house I may have no other option than to tow the vehicle to a Mercedes dealer where they will likely promptly screw me over.

I've already had he engine balance sprocket issue come up with this car and it was fixed under warranty. I've also had the transmission hard downshift issue also fixed under warranty and it seems AirMatic is the most common other component that could fail.

So the question is how much sense do you think it makes to replace the shocks with Arnott shocks preemptively rather than wait for them to fail at some inopportune time? I plan to keep the car for about another 1-2 years before I buy a Tesla Model S so I'm thinking maybe I should just go ahead and replace the Airmatic shocks now... The only thing is then I'd have to replace all 4 as I would not know which one would fail. Wish there was a way to tell which shock is more likely to fail.

Michael.Sinz

Arnott has impressed me. I called them when one of my front struts failed (the right front, which, I have found out, is the most common corner to fail). I ended up replacing both just because I wanted to be sure the ride was balanced between the sides and I did not want to be "stranded" with the dreaded "car too low" message.

Would I per-emptively change them? I don't thinks so. I still have the factory rears. (I have 140K miles on my 2004 E500). But, one thing I do know, when they go, I will absolutely get the Arnott replacements.

PS - a local independent shop here says that they see far more of the Audi airmatic failures than the Mercedes parts but they also, almost exclusively, replace them with Arnott parts.

Buelligan

Hmm. Very interesting.

I'm wondering if high frequency, low amplitude vibration is causing these shocks to fail prematurely? I had a tire mounted on the left front that was slightly out of balance for about 10,000 miles. The vibration wasn't that bad and it would happen only at certain speeds (as far as I could tell) so I never addressed it. Now I'm wondering if it helped kill that shock?

I had a motorcycle that was recalled for this very issue years ago. Vibration would kill the shock seals eventually and the manufacturer recalled every motorcycle they made for two years to replace them.

I think one thing we could all do to possibly extend the life of the Airmatic front shocks would be to make sure the wheels are as balanced as you can get them. It surely can't hurt.

Michael.Sinz

From just the physics of the situation, any motion has some (hopefully very minor) impact on the materials that flex/expand/contract/slide/etc.

The seals and air bags, by their very nature, flex/bend/move as the wheel goes up/down over the contours of the road.

Now, the rate of failure may be too high (thus showing the wrong material was used or poor manufacturing) but the reality is that it will have a limited lifetime. (The limit may be 5K miles or 500K miles but there is a limit)

The interesting thing is that the pattern was not just in our W211 or Mercedes but Audi and a few others where the right-front was the most often replaced air suspension part.

Buelligan

That's probably because most road imperfections are closer to the edge than in the center of a road and most cars use the right lane in two way traffic. I wonder if it's the left side shocks that fail first in England and Japan?

I just called the local dealer to see how much money I saved: $256 plus tax on labor (2.5 hrs), $880 plus tax on the shock. Not a bad sum of money I saved doing this myself.

I got royally screwed by the dealer a few years ago when they said the transmission needed to come out to fix a rough shifting issue. They never explained what they did... I might have to go back and have a meeting with the service manager. I think they blatantly cheated me on that one.