I have just replaced a front Airmatic strut with a rebuilt from the excellent folks at Arnott. The installation was done primarily using the instruction sheet that comes with the strut, and I thought that some additional notes might help others with the installation.


Required tools:
Jack (an additional small jack is helpful).
Lug wrench or socket for wheel removal.
Small screwdriver or pick to remove wire on harness connector.
A really good 5mm hex bit, extension and ratchet or pull handle.
A 10mm open-end wrench.
A 15mm socket & long handle, or long wrench.
A 17mm socket & long handle or long wrench.
A good lever-type ball joint removal tool.


Slightly condensed instructions, just to add comments.
1.0 Set steering to straight ahead.
2.0 Remove the air compressor fuse... The fuse is difficult to remove, and pliers or some other tool may be necessary. Try to avoid damaging the fuse.
3.0 Raise vehicle. Remember to break the wheel bolts loose before jacking. It will be much easier to install the strut if both front wheels are off the ground - otherwise, the very stiff anti-sway bar will hold the suspension up, making strut removal very difficult. Work safe!
4.0 Remove front tire.
5,0 Disconnect the shock control cable connector... The connector is held in place by a wire retainer. Use a pick or small screwdriver to pull the wire up and off. Cut the wire tie holding the cable bundle and unsnap the cable from its retainer. It is possible to work the connector out and off by manipulating the cable so it is free of the other cables. Be careful to avoid damaging the cables. OK, the learning continues! The shock connector is actually snapped onto another matching connector, and both connectors must be removed together. They simply snap apart after removal.
6.0 Loosen the two (2) set screws... Good luck with this. The 5mm hex setscrews were installed with locking compound. Make certain that the hex bit is fully seated in the screw. Have a good hex bit - I broke two bits.
7.0 Raise the hood.
8.0 Disconnect the air supply line... 10mm wrench. Don't let the line twist.
9.0 Remove the three (3) nuts holding the top mount... 15mm.
10.0 Remove the ball joint... A good lever-type tool is the way to go. Remember that many auto parts stores have a "free rental" tool program.
10.0 (cont)...remove shock assembly... Yeah. You have to pull the lower suspension down enough to pick the strut up and pull the bottom pin out of the mount. That is probably impossible unless both front wheels are off the ground, and it is tough anyway. A long lever to pull the arm down is helpful.
11.0 Removal complete.
Take the time to inspect everything - ball joints and boots, brake pads, etc.
Installation is pretty straight-forward.

Getting the bottom pin back in the mount can be tricky - put the top nuts on to hold the strut up. You will need a jack under the suspension to push the pin into the mount.

After getting the setscrews tight, use the jack to push the suspension up to install the upper ball joint. You might need to carefully tap the ball joint into the tapered seat so it doesn't spin as you turn the nut.

Installing the shock solenoid control cable requires that the connector must be snapped to the matching connector, and both must be installed together. Ensure that the pair of connectors is fully seated in the sockets. If they are not fully seated, you will get a warning - Airmatic - Visit Workshop every time you start the car, and the socks will be on full firm!

Remember that you have a wheel installation stud tool in the tool kit.

Read and heed the warning about how to inflate the strut.

If this is your first strut, be aware that the free return shipping label is under the invoice in the plastic on the outside of the box.


I hope that these comments help!

 

Thanks ! How's long did it take you?

 

This was my first time changing a front strut, I was in no hurry, and (as you could tell from my comments) there were some difficulties. Thirty minutes prep, two hours working, thirty minutes clean-up. I could do it in an hour less next time, and my comments could save a novice that much time on their first time.


I spent almost as much time with the STAR System after installation. For reasons unknown, my car dropped the front end (both sides) about 1 1/2"! I had to lean how to adjust the ride height with the STAR System, and clean up the trouble codes from the job. The car stored codes telling me that I had disconnected the shock control solenoids, that the strut length was not plausible, etc., etc.


I also ran all of the pneumatic tests - the System will test all of the components. I discovered that my compressor is not putting out max pressure - it should be able to pump the reservoir from three bar to fourteen bar in 40 seconds - mine only made it to eight bar. Enough to operate the Airmatic System, but definitely not up to spec.


As an update in the process, on 3/16/2014 I ordered a "compressor rebuilding kit" from bagpipingandy in the UK. (There are two suppliers for similar kits, both in the UK.) This kit consists of a new piston ring, a couple of O-ring seals, two new bolts and a few wire ties, and with UK-to-USA shipping, costs $50. The Wabco compressor uses a cast connecting rod with a rigid piston disk, so the piston wobbles as it reciprocates in a tapered bore. It has one large Teflon piston ring, which is probably pretty worn after 200,000 miles. Installation is reputedly simple, and this should bring the compressor back up to spec performance. I will report what happens, probably in three or four weeks.

 

"I spent almost as much time with the STAR System after installation. "...

Hi wallyp,

Do you have your own STAR system?

Thanks,

-robert

 

Yes. I bought an IBM T-30 laptop from eBay, and a STAR System from China. It is a great too and an even greater toy...

 

hey wally, i had the same problem but i didn't have my plugs in properly and it took care of my problem. i di do my second one in under an hour. good job on saving a pile of money.

 

wallyp - the Chinese Star with the T30 is great tool setup, will probably invest in something, just waiting something in the affordable range.

corkshoppe - good tip about the connectors

 

After thinking about it for a day or so, I now suspect that I have a problem with the shock solenoid connector, as the ride is now very stiff. I will hook the STAR System up tomorrow and see if that shows any codes...

 

Well, the learning process continues...


Yep, the shock connector was the problem. The shock connector is actually snapped to a matching connector, and the pair must be removed together, and installed together. It is impossible to install the shock connector alone.


Problem solved, ride is back to normal.


I have edited the original post to add the info about the connector.

 

I know this thread is a little old but was wondering if you used a hand impact wrench for the 5mm bolts?

I've read other places that you should disconnect the battery prior to replacing the shock if you don't have access to Star Diagnostics.

 

No, I used a 3/8" drive 5mm socket.

I understand now that it is a big help if you apply heat (propane torch, for example) to the screws to soften the Loctite applied at the factory.

 

A hand impact wrench would do the job and you could use that same 3/8" drive 5mm socket. I just changed an Airmatic shock today on my 4Matic and at first I couldn't get enough leverage to break the E-Torx bolts free but two taps with the impact wrench broke them free right away.