Audi allroad Front Air Spring Replacement

June 13, 2010 | by Jim Capp | Audi Maintenance | Share

Thou Shall Not Fear the Pinch Bolt

So your allroad has the dreaded death knell and is bowing to the air spring gods. No need to worry, as this is one of the easiest DIY’s to do on this car. And if you’ve done any suspension work at all, I assure you this repair is 10 times easier.

Before you go any further, get to your local FLAPS (Friendly Local Auto Parts Store) and pick up some PB Blaster penetrating oil and go spray your pinch bolts with it. If you can soak them for a day or two, it makes life MUCH easier. Don’t fight me on this! If you soak them for an extended period of time, chances are they will come out. This is, by far, the easiest way – we had my right front air spring out of the car in 15 minutes after wheel removal and none of us had done this repair before.

Audi Models

Audi allroad C5 (2001 – 2005)

Parts Required

Replacement Front Air Spring
O-Ring Kit
Shock Mount

Tools Required

Jack and jack stands
Metric ratchet set (16mm, 18mm, 19mm)
Metric wrench set (10mm, 16mm, 18mm)
Torx ratchet heads
Triple square ratchet heads
Allen wrench/spinner (something with leverage)
Torque wrench
Needle nose pliers
Mallet
Flat head screwdrivers (small and large)
Lithium grease
Large channel locks
Dremmel (optional)

Instructions

Overview of the Procedure

With the front of the car supported by jack stands and the front wheels off the car, we will be removing the airspring and shock tower from the car. Once removed, we will separate the shock tower, shock mount and strut from the airspring. We will replace the shock mount, airspring and o-rings with new replacements, reassemble everything and then reinstall them into the car.

Step 1

Place the car into JACK MODE by turning the key to the ON position and then simultaneously pressing and holding the suspension UP/DOWN buttons on the dash until the icon appears. Once the suspension is locked, turn the key off, open the hood, and remove the cowl cover. This is done by gently removing the rubber seal and pulling the plastic cover toward the front of the car. Once the cover is out of the way, you can access the three 16mm bolts that secure the shock tower.

Note 1: Now is a good time to look at your cabin filter and replace if dirty. Also take a flashlight and look under the battery for any sitting water or debris. If you see either, remove the battery and battery tray and clean out the area. Also, be sure to check the drainage hole beneath the battery. If clogged, water will backup and eventually seep into the passenger compartment and possibly fry some expensive electronics. This topic is the subject of a recent class action lawsuit.

Next, Jack up the front of the car, support with jack stands at the pinch weld/jack point. Remove the front wheels and place them out of the way. Next remove the fender liners with a torx head and ratchet.

Step 2

Using a 16mm ratchet and extension remove the three bolts holding the top of the shock tower in place. These bolts will be reused so put them aside.

Step 3

Using the 16mm ratchet and an 16mm wrench, loosen the pinch bolt that should have been soaking in penetrating oil for the last 2 days. If the bolt does not thread out on its own, you may have to give it a few whacks with the mallet and screwdriver/punch. Once the pinch bolt is removed, a few upward blows with the mallet are needed to free the upper control arms.

Step 4

Using a 10mm open end wrench, loosen the air fitting at the top of the air spring. Once free, you will hear the spring fully deflate. Adjacent to the air fitting, on the underside of the fender well, there is a PIA 1 cent locator clip that must be removed before the entire shock tower will come free. To remove this, use whatever works! In addition to excessive force and swearing, a small screwdriver, a hammer, a dremmel or needle nose pliers are all acceptable approaches. Feel free to mangle the clip. We did not replace it, the dealer does not replace it, but if you are super anal, it is a very inexpensive part.

Step 5

Loosen the 18mm lower strut mount bolt using a ratchet and wrench. If your car has never been touched since factory assembly, the bolt will be inverted, ie the head facing the rear of the car. If this is the case, you will need your floor jack to position the lower control arms in a position that allows proper clearance for the removal of the bolt. Be patient, once you find the sweet spot it will be relatively easy to remove, however, you may need the assistance of the mallet and a punch to push the bolt free of the hole. Once the bolt has been removed the entire assembly can be removed from the car.

Step 6

With the assembly out of the car, we can begin dis-assembly. We will start by removing the air spring from the shock tower. Using the ratchet and the triple square head, loosen the bolts. With all bolts removed, separate the shock tower from the air spring by simply puling them apart. With the shock tower removed you will now see the rubber shock mount. Using channel locks, grab the shock mount and loosen the strut bolt with a 19mm ratchet. Once you break it free, it should spin off without too much effort. If it does not, you may have to use some ghetto means to loosen it. My friend grabbed 19mm socket and held it with channel locks while I took the Allen key and placed it through the socket into the top of the strut. Using this method we were able to have one person turn while the other held and the nut came free. With the nut removed, the strut can be removed from the air spring. Discard the air spring, o-rings and shock mount immediately so they are not confused with the new parts.

Note 2: Inspect the strut for leaking fluid or damage. If it needs to be replaced, now is the time to do it.

Step 7

In the new kit, locate the two o-rings. Lube both with the lithium grease and seat the larger one into the channel at the top of the new airspring. Place the smaller o-ring over the top of the strut shaft and seat on the barrel. Insert the strut through the airspring and place the new shock mount in place. Tighten the nut for the strut using the same ghetto method we used to remove it — a socket held with channel locks and the allen key. Once tightened, lube the smaller o-ring with lithium grease and seat in the shock mount. Carefully align the shock tower with the airspring and hand tighten the triple square bolts while checking to make sure the the o-rings stay properly seated. Torque the triple squares in a star pattern (just like wheel bolts) to 23nm. Please note that we had to do 3-4 passes in a star pattern before achieving the proper uniform torque settings.

Step 8

With everything reassembled, you can begin to the reinstallation process. You may have to compress the strut a bit to get it back in the wheel well. Once you align the upper shock tower bolts, hand tighten them. Next, align the bottom strut mount bolt. You may need to use the floor jack to get the orientation correct. Feel free to re-insert the bolt from the front side as well. Fully tighten the 3 upper bolts and the lower strut bolt. Next, seat the upper control arms into the pinch bolt housing. You may need to use the mallet to get them fully seated. Reinstall the pinch bolt and make sure everything is properly aligned. Reinstall the air line being careful not to cross thread or strip it.

Step 9

Before re-installing the wheels, it is a good idea to pressurize the system and look/listen for leaks. Jack up the suspension and support it with an additional jack stand. Turn the car on and remove jack mode. The system should begin to pressurize and you will likely hear the compressor turn on. Once a level is indicated, put the car back into Jack Mode and turn the key off. Go inspect the airspring and look and listen for anything unusual.

Step 10

If all is OK, remove the jack stands from the suspension and reinstall the wheels. Jack up the front of the car again, remove jack stands at the pinch weld and start the car. With the car running, slowly lower the car until there is weight on the wheels, but do not lower it all the way. Remove the car from jack mode and allow some pressure to build before lowering completely. With the car on the ground, cycle through the levels to make sure all is working properly.

Step 11

Replace the cowl cover and rubber seal, close the hood, clean up your tools and you’re done!

Tags: air spring, allroad, c5, suspension

17 Comments

Greg Thomas
August 21, 2010 at 3:58 pm

Great article. I’m going through this procedure this weekend with the Gen IIs and Bilsteins form Arnott. As I finished the first side I pressurized the system to check everything as you suggest. All the hard parts like seal around the top where the old spring leaked looked solid. Very happy. The airline was leaking, however.

My Gen IIs did not come with a VOSS fitting installed though it’s pictured on their site with one and the Gen I instructions it comes with has a whole insert on the included VOSS fitting.

I noticed yours didn’t have one installed either. Did you just thread your line into the hole and it’s OK?

Thanks for the write up.

Greg

Reply
allroader
August 26, 2010 at 12:44 am

Love the write-up & the site. Keep the allroad tips coming. I’d love to see some performance upgrade DIYs.

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Ewing Fox
September 21, 2010 at 7:48 am

Thanks for the writeups… I love how Audi makes sure to tell us that oil is poisonus and that we should not drink it, but does not list the oil capacity… one more attempt to try and drive us into the net of dealer service!

I am heading into doing the timing belt on my ride (sounds like you are too at ~70k, dont wait much longer)

I work at a small Audi shop, but I am slammed… any chance that your 4 year old is available? Does he work on book or straight hours? My two year old has her own tools and stays off the phone when she has a car on the lift, but she wants $30/hr- not happening…

You must be this tall to ride:

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Reply
- Jim Cappuccio
  September 21, 2010 at 10:00 am
  
  LOL, funniest feedback comment yet !! We did my Timing Belt at 64K — we’ve seen those waterpumps go as early as 50K, so why risk it?
  
  Reply
  - DV
    March 3, 2011 at 6:09 pm
    
    A timing belt DIY would be VERY helpful!
    
    Reply
Jack Christensen
October 18, 2010 at 1:29 am

Jim,

In Step 8 you mention, “Feel free to re-insert the bolt [for the bottom of the strut] from the front side as well”. I did this using the bolt include with the Arnott supplied Bilstein shocks I also installed. But I worry that the threaded end of the bolt might interfere with the lower rear control arm. Have you experienced such an interference problem?

For reference, here are the tightening torques:

Nut at top of shock strut piston – 60 Nm
6 bolts holding air spring to suspension upper mounting bracket – 23Nm
3 bolts holding suspension upper mounting bracket (shock tower) to car – 45 Nm, plus an additional 55 degree turn
Pinch bolt/nut for upper control arms – 40 Nm
Lower strut mounting bolt/nut – 90 Nm
Lower control arm ball joint nut at wheel bearing housing – 110 Nm
Air inflation fitting at top of air spring – 2 Nm

Reply
Peter Gault
November 22, 2010 at 7:10 am

Thanks for this excellent guide – it helped me a lot this weekend. Just with regard to Step 6 – a hollow ratchet with a 16mm socket (I used a Draper Vortex, though I’m not sure you get this brand in the USA) allows you to use an Allen key or even better an Allen key in another ratchet to undo the top nut holding the strut and mounting together. This makes it a one person job, which is handy if you work alone like me.

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Scott Manning
March 12, 2011 at 11:26 pm

1) The pinch bolt was a nightmare. I suggest watching the Bentley video on U Tube. It recommends the use of an air hammer.
2) The strut bolt to the lower control arm is a nightmare. The bolt supplied with the Bilstein (Arnott supplied) strut is CANNOT be reversed! The bolt DOES hit the aft control arm on the suspension lowest setting. I learned the hard way.

Does anyone know how to get the strut bolt installed???? The only thing I haven’t tried is pulling the lower control arm.

Reply
- Jim Cappuccio
  March 12, 2011 at 11:42 pm
  
  Sorry to hear the pinch bolt and the strut bolt are giving you trouble. We reinstalled the OEM strut and hardware, so I’m unfamiliar with the Arnott Hardware. I would suggest re using the OEM hardware. We did have to use a floor jack to coax the suspension into a sweet spot
  
  Reply
Howie Bernstein
May 8, 2011 at 10:29 pm

I just did this over the weekend using your tutorial as a primary source with some others as backup… Step 6 – for me this was an 18mm nut – not 19, not 16. The other problem I had was with the collet. The Arnott instructions say to remove the nylon pin and insert the air line. If I were you, I would ignore this, and pull the pin, remove the collet, insert the airline into the nut, then place the collet onto the airline and seat it in the nut, THEN install the air line nut into the shock. This would be at the end of step 8.

Other items… I didn’t (couldn’t) remove the pinch bolt, so I compressed the strut, turned the steering wheel to the opposite side, and swung out the whole assembly. This is a little more difficult, I’m sure, but it works in a pinch

Reply
OCG
May 14, 2011 at 9:18 am

Great tutorial. I used it last weekend to replace my front bags with Arnott bags. I definitely suggest going down to Audi and grabbing 2 new pinch bolts for the $3 each that they are selling them for. I mushroomed the head of one of my bolts getting it out. It was nothing a SawZaw and a air hammer couldn’t fix. And I highly suggest an air hammer. Even if you use it with an under powered air compressor it will save you hours of work.

Thanks Again,

OCG

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Mark
July 10, 2011 at 5:37 am

Mr Cappuccio, thank you for this guide. I have no mechanical training but with confidence from this guide, a replacement bag from Arnott and some tools, encouragement and assistance from a friend who is good at this sort of thing, I have today replaced the passenger side bag on my Allroad. After a reasonable test drive, it seems to have solved the problem. The guide was clear and easy to follow. You have saved me a vast sum of Australian dollars.

Thanks also to Jack Christensen for the NM figures.

I have to say, a good clean and some WD40 the day before the repair and the pinch bolt came out sweetly.

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rinkadink
August 22, 2011 at 10:55 am

Excellent guide! – we replaced our front left airspring using this, all went well, thanks again.

Reply
Nate
September 12, 2011 at 10:15 am

YOU SHOULD FEAR THE PINCH BOLT!!

You guys must have got lucky… I soaked the pinch bolt for 3 days in PB blaster penetrating oil before attempting to replace my front air springs. First side we attempted the head of the pinch bolt broke right off leaving only the threaded side to work with. Tried as hard as we could to knock it back through with no luck. Moved to the other side and could not get the pinch bolt to budge. Looks like the bolt is rusted in there. Does anyone have an suggestions? We are going to pull out the whole assembly and drill out the pinch bolt that was broken off. Still hoping to get the pinch bolt out on the otherside! Need suggestions!

Thanks,
Nate

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Dad
September 18, 2011 at 2:56 pm

I had to drill the bolt and pull it through the nut end.

Buy a right-angle drill. Using a hardened drill bit that is approx 2/3 of the diameter of the stuck pinch bolt, drill into the end of the pinch bolt, starting at the end where the bolt head snapped off. Make sure you drill nice and straight and directly along the center axis of the bolt. Your objective is to hollow out the bolt for about 1.5 inches of length, so that it collapses when you try pulling it through the hole. (I predrilled with a smaller bit, then followed up with a larger diameter bit once I determined I was along the right line).

Buy a stack of washers that fit on the broken bolt.

Remove the nut, put a few washers on, and put the nut back so that you can grab enough threads on the bolt end to be safe (at least 6 or 7 turns, or until the bolt starts to poke out through the nut). Slowly tighten the nut down so that it starts to pull the bolt through the steering nuckle. Remove the nut after 3 to 5 full turns. Put some more washers on the stack, put the nut back on, crank the nut tighter. If you drilled out enough of the bolt, it should start pulling through hole until you can yank it out.

I think I had a stack of washers built up to about an inch thick beneath the nut before the bolt finally pulled through. And I found that my drilling was pretty accurate. I saved the bolt.

Ream out the hole after you get the bolt out. You want to clean out all the junk and corrosion before you put a nice new bolt back in when you are done with the project. You also should clean off the gunk and corrosion on the ends of the control arm pins that will need to accept the new pinch bolt at the end of the project.

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Stu
October 24, 2011 at 10:28 am

Thanks for the great article. I did this job over the weekend and it went really well. I was able to follow the directions exactly but I still have the same issue.
My passenger front corner sags to the ground overnight. I am going to get back in there and check for leaks but if I had to guess it is around that new fitting that comes with the new bag. The line that I pushed in till it stopped looked a little misshaped and maybe it didn’t get a good seal. I’ll post back what I find but in the mean time any suggestions would be great. Thanks again!

Reply
- Jim Capp
  October 24, 2011 at 11:02 am
  
  Spray soapy water on the air fitting connection to see if there is any leaking. The other likely culprit is the o rings.
  
  Reply