ParadiseLV

I know this is an old thread. But I need help. First, I cannot get the bag into position no matter how hard I try. I'm thinking I need a 2nd person to hold everything down. 2nd... With the new Arnott air bag the air reservoir is eliminated. I've cut the line and removed the bag. What do I do with this line? Do i remove it, plug it? Also, will I be throwing a cold with either of these options?

coupesedan

Undo the sway bar link, it'll be easier to push down on the suspension. You can cut the hose at the tank and wrangle it out or just leave the hose hanging.

ParadiseLV

So after following the instructions, I finally finished. I used a Jack and two jack stands. Things I learned are:

1. You need a 2nd person for this job. If you have access to lift, you can ignore this. You just can't push the control arm or hub down enough to position the airbag in the channel and get it lined up. The 2nd must (should) stand on the hub and you need a long screw driver to stick in the bolt hold of the control arm to keep it down. If you do these two thing, the bag will slide right in. Once in, you can compress the shock to line it up correctly.
2. If you are using A-2724, you can safely puncture/cut the air reservoir line. I used a serrated steak knife. The only reason I cut the line is because the clamp holding the line was to hard/difficult to reach. I have no error codes. I haven't figured out how to remove this line yet.
3. Use a pair of needle nose pliers to loosen the nut for the airline
4. When putting everything back together, lift the car at the differential just enough to ease tension. All the bolt will slide right in.
5. When finished, drop car just enough for the tires to touch. Then start the car wait two minutes to fill the bag. After two minutes, drop it the rest of the way.

When doing this by myself, I struggled for two hours trying to get the airbag seated. When my friend came over, it took us 20 minutes to figure how to get it in. When we moved to the other side, It took us less than a half hour to do the removal and install.

coupesedan

You most definitely don’t need a second person for the job. Get both rear wheels off the ground using the body lift points and you won’t be fighting against the swaybar. I tried wrangling the old bag out like a gorilla until I remembered how the suspension works.

E63007

I'm in the middle of rebuilding my entire rear suspension ( New Hubs,Flanges, rust treated and painted the dust guards, New Subframe Mounts, Rear Carrier Bushings, RMT Rebuilt Air Springs, new OEM Shocks, New differential Bushings, New Bolts all around, M-Factory LSD with 3.06 Gears from a 07" SRT8). I also fixed a Rear Main Seal Leak and subsequently cleaned out my Tranny Valve Body. I also dropped my drive shafts and have new drive rubber disc's. I dropped my whole Subframe to install the mounts with a tool made from 3/8 threaded rod w/14 mm Nut, washers incrementally sized up to very large, steel plumbers pipe connector, an assortment of short pipe just larger than the Bushings, used a large PVC pipe big enough for the Subframe Bushings to extract then cut a inch or so off to install the fronts. I had to employ the use of some wood wedge/shims cut and fit under the large washer in order to seat those front side Subframe mounts. To remove them, by the way, they will both explode when you crank on that Nut on the threaded rod as they are each filled with oil! It got all over my knee and knee pad! I used some shopping bags to cover the other side. Then it's a matter of using some sort of cutter to get the bottom half out which is a steel cup surrounded by rubber. I used a Die Grinder and one of those cone shaped fittings and deliberately made a slot up and down until finally it breaks through the steel. This is when you smell burning rubber. Since that cup has arim on it and using that cone shaped fitting is awkward once you get to the rim side, I but a small cut off wheel that fit in the Die Grinder to cut that top rim part. Then I used a lever to get under that rim and collapsed the cup and prayed it out.

It was relatively easy for me to install the Air Springs on each side once the Subframe was lowered as I used Oetiker Hose Clamps from above to re-attach the Air Hoses to the OEM Springs. I ended up using Camshaft Bolts left over from my Engine build that are same size as the subframe mounts but only about 3/5 inch longer to temporarily mount the subframe while I disconnect the Differential to start the install of the LSD and 3.06 gears. The longer Bolts made for an easy line up since, while raising the subframe on my Tranny lift, the driver's side was higher up, so I attached that side first with the longer bolts just threading them in safely allowed enough to hang freely while then using the jack to raise the subframe and manually lifting the other side with my free hand and lining up the the bolts for the other side. Since I'll be having to re-attach the Subframe in order to remove the rear differential, I'll use those Cambolts to more easily attach the Subframe, then when I'm ready to use the new bolts, I'll support with the jack below and remove each one by one with locktight blue and then torque them down.

I'm still about half way through the build, but I feel it important to mention, since no-one has, that when tightening up all the Control Arms one should be using new bolts as they are all torque to yield, meaning that say when the WIS Calls for the rear Air Spring Bolts to be tightened to 150Nm + 90* (using as reference, not certain as I'm not with my STAR/DAS WIS) that extra 90* is meant to intentionally stretch that bolt never to be stretched again!! Moreover, all the bolts should only be tightened up against the Bushings once the rear end is in driving position. Think about measuring the distance from the ground before you detach everything only after deflating the rear air springs. The tension on those rear upper Arm bolts against their relative Bushings will allow for those arms to stay in their proper position (i.e.- once the carriers, axle Shaft are removed, Arms will remain in their position relative to their slightly offset mounting points to the Rear Carrier.). Then use a floor jack to prop up the Carrier until the rear Control arm is at that level before tightening everything up. Trying to do this with wheels on would be next to impossible! If the Subframe is removed from the car, you can scribe a mark on each arm when you remove the arm(s) to replace the Bushings with K-Mack, for example, so that when you re-attach them, you tighten them relatively easily as you stand above the Subframe!

Also, when installing new bolts, its a good idea to pre-prep the bolts with Blue Lock Tight. The jury is out whether or not to allow it to completely dry before install, but when you take those bolts out you can see Mercedes having liberally applied a lot of the stuff especially on those subframe bolts. I spent considerable time with a scratch awl and wire brush manually cleaning the threads of the bolt holes. When it comes time to re-install the Differential, only then will I attach the Air Springs and add the white clips only when the Subframe is reinstalled. As for the airhoses, there a 3 way junction in the passenger side mid part of the Subframe attached to a mounting ear extending from the rear Toe Arm mount bolts base. Make sure you disconnect the air hose that "supplies" incoming air to both Airsprings. You'll see that it points upwards whereas the the other two lead to each Airsprings. WIS Doesn't mention this point! If you lower the Subframe with out disconnecting, the air supply line will break! Also, the Electrical cable which attaches to each Airspring must be disconnected too. It is mounted on the opposing ear extending Driver Side.

As it looks now, I may have to use STAR to add 0.5 bar or so in order for the Spring to extend enough in situ to both attach to its lower mount bolt and be seated onto this upper white clip which screws in place to the base of the car first and then you expand the Airspring using STAR/Xentry until it gets real close to the clip. Then Raise each arm with a jack while making sure the airspring clips onto this clip by hand otherwise the clip will break! This means you need two jacks to raise each arm separately in order to manually line up each side. The tension from the upper arms being tightened to the Subframe will provide ample support to the lower Airspring arm once the Carriers are reattached and torqued down making sure the rear axle is -1* from level (this is approx where the rear axle will be in its highest setting-so while not ideal it allows one to use a jack to raise each carrier to the correct level before torquing each bolt.

Mounting the rear Airsprings with the Subframe removed allows you to attach both the air expansion hose and the tiny air hose. I thought I'd have to pull on those air hoses in order to access the rear differential bolts, but by simply pushing up on those ears that the rear Toe Arms bolt into you can gain access to the rear Diff Bushings bolts. As for the Subframe, it now appears I can drop the rear section enough with those longer Cam Bolts in order to access those rear differential bolts more easily. Otherwise the spare tire carrier is too close to gain accesss if the subframe where fully locked down! Edit-scratch that- the Cam Bolts are not long enough to lower the Subframe enough to gain clearance for me because the Torx sockets I have are 3 1/2" long. If a had a shorter Torx, the maybe then there would be enough room to get a 1/2 Drive wrench in there! I'll have to use the jack to support the rear Subframe, remove the bolts and lower enough in order to gain access to use my bush removal tool!!

I hope this helps any any of you DIY'rs out there!!