B5 – Coilover Installation

  B5, DIY

1. Jack up the front end and remove both wheels. If you don’t have jackstands, get some. You need to have both sides lifted so you’re not working against torsion in the sway bar. (Sorry, no pic…if this is beyond your capabilites, stop right now and get thee to a shop)

2. You’ll need to remove the plastic piece at the rear of the engine compartment. Grab one end of the rubber sealing strip and pull towards the front of the car. Once it’s off, do the same thing with the plastic.

3. [Editors note: This method is not advised on cars with any sorf of mileage on them. This Pinch Bolt tends to weld itself in, and can be VERY difficult to remove. Only remove this bolt if you also plan on changing the upper control arms at the same time. Check THIS article for an alternate method ] Pick a side, and get started by removing the bolt holding the upper control links to the suspension upright (or bearing carrier, or whatever you want to call it–the big part that the wheel attaches to). 16mm.

4. Pop both of the link ends out of the upright. You will probably have to use a hammer and punch to get them out. They’re under tension from the bushings at the other end, so they will spring up a bit when they come out. The upright/hub/brake is loose from here on out, so try to keep it from knocking around too much.

5. Take off the lower shock bolt. 18mm. You may have some trouble getting the bolt out; it tends to be blocked by the rear lower control arm. Carefully move the upright around until you can get a straight shot.

There’s a decision to make here. There are two ways to dismount the top of the shock from the body. The way I’ve seen in most write-ups is to remove the three 17mm bolts and take out the whole upper shock mounting plate, together with the attached upper links. The other way is to remove the two 13mm nuts holding the shock to the mounting plate, leaving the mounting plate and the upper links attached to the car. Each way has it’s own PITA bit–the first method requires removing an annoying locking ring from the locator pin, the second involves prying/gouging out two plastic plugs that are glued into the car body. I chose the second method, for a few reasons: I thought it might be easier/less awkward moving the shock around without the links attached, fewer parts sticking out to possibly scratch things (i.e. paint on the fender lip), it might possibly avoid some microscopic changes to the suspension geometry, and two small nuts should be less work than three big bolts (yeah, I’m a lazy SOB). This is also the method that the Bentley manual uses, so what the hell. No comment on which method is easier. I guess I could have done the left side one way and the right side the other, but I didn’t think of that until I was finished. Anyway, if you choose to go with the three bolt method, fine. You’re on your own for a few steps, but I’m sure you can handle it.

6. Find the two plugs (mine were painted to match the body) covering the upper mounting nuts. One of the plugs on the passenger side is blocked by a tab attached to the battery box (wtf this is for, I have no idea), but if you remove the 13mm bolt just in front of the battery, this loosens up enough so you can get in there.

7. Pry/pull the plugs out. I tried to preserve them, but with the amount of glue they use and the tight work space, it’s kind of hit or miss.

8. Loosen (but don’t remove) the two upper mounting nuts. 13mm. You want enough slack so the shock can move around, but you don’t want it dropping down just yet.

9. Push down on the lower control arm a bit, until you can pull the U-shaped bracket on the end of the shock clear and move it towards the front of the car.

Note: In step 9 for the front suspension, S4 and A6 owners may have an issue lifting the shock over the lower control arm to remove it. If this is the case, remove the belly pan, and remove the (2) 13mm nuts on each front sway bar bracket (not shown in the pictures). Also unclip the leveling sensor on the driver’s side lower control arm (not shown in pictures). This leveling sensor is only on cars equipped with xenon headlights. Finally, remove the inboard bolt that attaches the lower control arm to the subframe (not shown in pictures). The lower control arm can then drop enough that you’ll be able to lift the shock over the control arm and out of the car. When you put everything back together, make sure you torque the inboard bolt on the lower control arm while the vehicle is at ride height (place a jack under the wheel bearing housing, and lift the axle to approx. ride height. Consult Bentley for a torque spec on the lower control arm bolt. In the absense of that, 60 ft-lbs should be sufficient.

10. While supporting the shock (either with your free hand or by resting it on the lower control arm), remove the two upper nuts.

11. Carefully remove shock assembly from car. Watch the fender.

12. Now the fun starts. Take the shock to your work bench and get out your spring compressor(s).

13. Put a compressor on each side of the shock and snug them up. I used the supplied safety hooks, but found myself wondering if I’d be wearing them like bellybutton jewelry if something went wrong. Be sure to get the compressors as diametrically opposite as possible to balance the load. If your spring compressor is different (read: better than the POS I’m using), follow the instructions that came with it.

14. Compress the spring *slowly*. 24mm or 15/16″, I guess you could use a crescent in a pinch, but I wouldn’t recommend it. I did a full turn on alternate sides. That may be a bit cautious, but this type of compressor scares the crap out of me. If you go more than two turns per side, you’re nuts IMHO.

15. Squeeze the spring 12-15 turns, about 3/4″ to 7/8″. Any more, and you may be taxing the compressor; less, you’re asking for more excitement when you take the shock apart. If anything starts bending, creaking, cracking, or otherwise acting strange, STOP!

16. Now you’re ready to take the top of the shock off. 18mm. I didn’t have any problem with the shaft spinning on either shock, perhaps that had something to do with the age/condition of the suspension (~27,000 mostly highway miles). If the nut won’t break loose from the shaft, you may have to get creative–see step 25 below for ideas. The cap may pop off with a little force behind it (depending on how much you compressed the spring, it moved a couple inches for me), so you may want to clear stuff out of the way.

17. Success! (No, that’s not how far the stuff popped off)

18. Pull the shock body out of the spring, then *slowly* un-compress the spring. Bear in mind that the spring will expand to its free length, so it will take more turns than you put into it. It expanded over two inches from compressed–>free in my case.

19. Take the rest of the shock apart. The parts you’ll need are the jounce bumper/dustcover and (perhaps) the spring seat.

As far as the next couple of steps go, they could be considered optional. My coilover kit (H&R) didn’t include a spring seat, nor any instructions, so I guess they intend that you just let the spring rest on the perch as shown in this picture:

I’ve seen lots of installs like this, and I’m sure it probably works fine, but to me it looks like a potential source for squeaks/rattles. If the front springs were like the rears (tapered, pounded flat, whatever) and sat more flush on the perch, I wouldn’t care. Piggie talks in his write-up about using the stock spring seat, so that’s good enough for me. Other than it being a bit of a PITA, I can’t think of a good reason not to do it. If you disagree, then please feel free to ignore the relevant steps.

20. The spring seat doesn’t fit nicely on the spring perch, so you have to make adjustments. Pull out your weapon of choice and have at it. I used a large exacto knife. *Note* Performing this step makes it impossible to revert to stock without obtaining some new spring seats.

21. When you can set the spring in the seat and the bottom coil fits around the raised lip of the perch, you’re good to go.

22. Put the shock together. Turn the adjusting ring and the locking ring all the way down (mine were shipped at the top). The washer goes silver side down against the adjusting ring. Put on the perch/seat combo, then the dust cover/jounce bumper. Then put on the spring, widely spaced coils at the bottom.

23. Stand the shock up and put on the upper seat/perch. Fit the end of the coil into the groove.

24. Put the new washer on the shaft. I adjusted the lower perch up a bit so that the washer was about even with the upper perch, that way I could be certain that the washer wouldn’t snag above or below the perch when I started to tighten things up.

25. Put the rubber cap and new nut on and tighten the nut. 19mm (the stocker is 18mm, go figure), 6mm for the hex hole in the shaft. If you have or can find the proper deep offset wrench, good for you. I had to improvise with some vise grips and a deep well socket. If you have Proto/Mac/Snap-On/etc, you probably will want to go get a cheapie socket set like I did. I used a piece of half inch pipe to hold the allen wrench. If it matters, Bentley says to torque a new (stock size) nut to 44 ft lb.

30. All put back together, ready to go back in the car. Unfortunately, I didn’t have a clue about where to set the perches. This is something that’s definitely easier to do out of the car.

31. Put the upper perch back into the shock mounting plate and loosely install the nuts. Bentley says to use new ones. This can be a bit tricky if you’re by yourself.

32. Installation is pretty much the reverse of removal. Some tricky bits may require jacking up the suspension to get the lower bolt in, or gently prying the gaps on the upright in order to get the upper links back in. Tightening sequence and torques follow:

Lower shock mount to control arm. New nut, 66 ft lb. Bentley says to do this with the car on the ground to avoid putting stress on the bushing. I just jacked up the suspension a few inches.

Upper control arms to upright. New nut, 30 ft lb.

Upper shock mount to mounting plate. New nuts, 15 lb ft.

Bonus info: If you happened to use the three bolt method, the torque value for the 17mm bolts is 48 ft lb.

33. Before you put your wheels back on, adjust the preload on the springs so that both sides match. The big ring is for adjusting, the small ring is for locking the big ring in place. The more threads showing below the rings, the higher your car will sit. This is a lot of fun, 1/8 of a turn at a time, about 16 turns per inch.

34. I started with one inch of threads showing below the lock ring.

35. A lot of people might think this is too low. I agree with them. I think a better starting point is 2.5 inches or so of threads showing. Personal preference, wheels, tires, driving environment, etc. will all play a part in how you set up.

36. Put your wheels on and get the car on the ground. If you didn’t totally mangle the covering plugs, you can put them back in (<cough> duct tape). Re-install that tab that was blocking one of the top nuts on the passenger side. Put the plastic cover and the sealing strip back on. You’re done!

Compared to the fronts, the rears are a piece of cake.

1. Put the car up on jack stands, remove both wheels. Again, if you try to lift/do one at a time you’ll be working against the sway bar.

2. Remove the lower shock mounting bolt. 19mm. You’re probably going to have to move the parking brake cable out of the way to get the bolt out. You may also have to ‘encourage’ the bolt to come out with a hammer and punch.

3. Remove the upper control arm bolt. 18mm/19mm. Just like the fronts, it will pop up a bit when released from the tension in the bushings.

4. Remove the four bolts holding the upper housing to the car. 17mm.

5. You need to separate the bottom of the shock from the lower control arm, then push it towards the car in order to lower it into the gap between the control arm and the car. (Ignore the jack, it’s not doing anything)

6. Be *extremely* careful here. Quarters are very tight, both the upper control arm and the upper shock housing will get very close to the fender lip. Complicating things are the locating pins for the housing and the wheel liner–the edges of the housing tend to hang up on both of them. Slowly lower the shock into the hole, then tip the upper part out away from the car. Lift the whole assembly up and out.

7. Take the shock someplace where you can work on it.

8. Remove the upper mounting bolt. 19mm.

9. Once the end of the bolt clears one side of the housing, force from the spring will pull down and bind the bolt. Using a punch is tough since the end of the bolt is conical. Luckily, you can simply turn it out with a ratchet.

10. When you do get the bolt all the way out, the shock will pop out three or four inches. Move your beer out of the way first. You could also use a spring compressor here if you want to avoid the excitement.

11. The rear coilover is pretty much a direct replacement, no parts need to be pirated from the old shock.

12. If needed, bottom out the adjustment ring on the shock (mine came that way). Insert the shock into the housing, matching the spring to the seat.

13. The shock won’t quite reach the hole, but it’s easy enough to push it down with your hand to get it to line up. You may have to fiddle a bit to get the rotation of the shock hole just right. Put on the mounting bolt. Bentley says to use a new nut *and* bolt. Tighten to 52 ft lb plus 1/4 turn.

14. Having learned my lesson on the fronts, I adjusted the springs *before* putting the unit back on the car. The punch is just to keep the lower part of the shock from turning.

15. I left 1.75 inches of thread below the collars. I would probably go more like 2.25 if I were doing it again.

16. Ready to go. Watch the fender when you slide it back in. Installation is the reverse of removal. Assemble everything, but don’t tighten anything yet.

17. The hardest part is getting the lower mounting hole lined up. In addition to the up-down/left-right, the shock lower can (will) rotate out of whack. A floor jack and a long punch, drift, sacrificial screwdriver, etc are helpful here. Be patient and try not to get angry.

18. Tightening sequence and torque values from Bentley:

Upper shock housing to body, tighten all four bolts to 41 ft lb.

The last two bits are to be done with the car on the ground, according to Bentley. The idea is to avoid preloading the suspension bushings. Good luck with the upper control arm bolt; I’m sure you could fit a torque wrench around the tire easily, provided you remove the fender. Instead, I just jacked up the suspension a few inches to simulate being on the ground.

Upper control arm to bearing housing. New bolt, nut, and washer. Tighten to 37 ft lb plus 1/4 turn.

Lower shock to control arm. New bolt and nut, 52 ft lb plus 1/4 turn.

19. Wheels on, car on the ground, done.


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