PStapes

Hi,

This is my first post, but having just finished a front end Arnott air spring install, with Bilsteins, I thought I would share some experiences (not sure I would call them tips, but I'll try). There is an excellent guide on air spring replacement here, and I'm not trying to recreate it - but for someone who had not done Audi suspension work before I thought there were a couple of steps that could use some color.

There are many accounts here and at other sites that this is an easy job for the DIY-er, and I suppose it is do-able. On a scale to 10, if changing a tire is a 0.5 and a brake job is a 3, I would call this a 5. Note that my 10 isn't a transmission or engine rebuild - that would be a 15 or 20 for me. I would do it again if I had to, but it took me about 8 hours over three evenings - not counting parts runs - and I ended up buying about $350 in tools, of which I didn't use about $100 worth and will return.

So, in order of uninstall/install here were the gotchas.

1. Pinch Bolt: I read multiple accounts of this challenge, and soaked it with PB Blaster for a few days before the job. I tried to remove it with a breaker bar, but saw the bolt head turning but not he bolt threads turning - and stopped in time. Broke down and bought an impact wrench (FYI - a decent home nailer grade compressor will run an impact wrench. My DeWalt 200 psi, 5.1 CFM did fine. I was surprised). This seemed to be the way to go. If you haven't used an impact wrench before, and I had not, you have to hold there and run it for awhile. Like 60-90 seconds. Then the bolt will move 5 degrees. Then 10. Then finally come free.... Initially I only tried for 15-20 seconds at a time, and it didn't work at all. It seems to require the persistent effort to break free.

2. The strut bolt was easy to remove the nut from, but the bolt wouldn't come out without dropping the lower control arm (the one with the ball joint that has the nut below the hub). The ball joint was easy to remove the nut from, but not to free from the hub. I tried jacking up the hub (stupid idea). I hit it on the side with a 16oz hammer while apply upward pressure with a jack. No effect. I sprayed and sprayed with PB Blaster. No joy. Finally I rented a front end service kit at the local auto parts store. Not one tool in the set was of any use at all. So I bought a decent 4 pound hammer (the largest at Home Depot), but the nut on the ball joint until it was even with the end, and hit it once. Just once. Came right apart. Same for the other side.

3. Upper control arms: I tried to free those with a pickle fork ball joint tool. Big mistake. Tore the ball joint boots and ended up replacing the upper control arms. (It turns out the bushings were cracked, so it needed to be done anyway - or so I tell myself.) I tried the front end service kit tools - nothing fit. Wailed on the arms with the hammer - no joy. But a cold chisel (blunt, round tip) and the hammer and a couple of good whacks to the bottom of the studs got them free. They had, of course, been soaked down with PB Blaster first.

--- For me recurring the lesson seems to be: don't be afraid to whack on the components with a 4 pound hammer. I was nervous about this, but had I gone for the hammer first I wouldn't have torn the ball joint boots. (I take no liability for the massive damage that you may cause to your Allroad. I'm just some dude on the internet, not a tech, not a good mechanic, not a mechanical engineer.) ---

4. Air spring mounting bracket (?) - the big aluminum piece that holds the upper arms and the air spring. Those aren't Torx screws. They kinda look like Torx screws. They aren't. I know, because I bought $75 bucks of Torx drivers at Sears, none of which fit. It's a 12 pointed, or triple square, fastener. 8mm. I found one at my local auto parts store. And the inside of the mounting bracket doesn't really clean up to perfection. I tried degreaser, mineral spirits, dish soap, etc.

5. Upper o-rings: I thought Arnott had sent me the wrong size. The old, flat, un-reuseable o-rings from the Audi springs seemed to fit better. I went to the dealer, and paid $84 for two air spring install kits to get the 'proper' o-rings. Guess what - the exact same size as those from Arnott. They seemed slightly too big, and wouldn't stay flat. I tried warming up the springs to 80-ish degrees to see if that made a difference. Nope. This is where the 'lubricate the o-rings' step is important. I was using spray-on white lithium grease, which isn't thick enough. You need the paste type lithium grease. The grease sticks the o-ring down in the track and then it will stay flat so that you can bolt it up to the mount. It took me awhile to figure that out....

6. Air line fitting: Arnott sends a new one along with the spring. It's a brass screw plug with a collet. I hate to shout, but the COLLETS ARE VERY FRAGILE! Why did I have to yell that? well, I broke the collets taking off the old ones and putting on the new ones. They DON"T BEND. They break. The dealer charged me $43 dollars EACH for new fittings. That's about 1/6 of the price of the air spring from Arnott. I found a post from Ex-PzKW Cdr where he said that he cuts the line at the fitting, and there is enough air line to do that. I cut the line just above the collet with a razor knife, and then the new one slid on without breaking - but it's a very tight fit.

7. And installation is the reverse.... no. Not really.

7a. Getting the lower ball joint back in the hub. I jacked the hub up and down, turned the steering wheel back and forth, tapped with a rubber mallet. To be honest I'm not sure the magic combination was. I think I had the wheel turned about half-way in the direction of the side of the car I was working on, the hub medium low, and managed to get the tip of the bolt in the hole. And then it just went in as I jacked up the hub, no problems. But I wrestled with it for about 15 min to get there. The second one was no easier. I think it's just a 15 minute threshold.

7b. Upper control arms - they didn't want to go back in. Tried tapping, etc. Took them out, used WD-40 and a battery terminal brush and cleaned the inside of the pinch joint, coated them with anti-seize, and on the first side both went in with just a little persuasion. The second side, the front arm was no problem but the rear wouldn't go. I finally used a wood working clamp from the slot in the front of the hub carrier to the arm behind the ball joint to put pressure on it, and tapped with a mallet. It finally dropped in.


That's it - I'll report if there are any other issues, but I'm not expecting any. Sorry for the lack of photos - I didn't want to expose my camera or cell phone to the grime on my hands.



Peter