This is the procedure I have from Clint Stephenson, he posted it on the A8 list at quattrofans.com earlier this year.

A couple of notes:

I looked at the Bently, and it states that the seat must be removed from the car. However, from the pictures below, it does not appear that the seat was removed from the car to take the back cover off. It does state that if the seat is to be removed, you need some special tool (wiring harness) to plug into the seat to ground it out so that the airbag won't go off (don't know if it would anyways).

I would start by doing it with the seat installed. The rest is Clint's exact email on how to do the repair. If anybody does this, please take some more pictures and we can put together a more detailed procedure and make a PDF document out of it.

------------------


Hello, I just signed up for this list and thought I'd just jump without
checking the archive and just start spewing the one tidbit of advice I
have so far about my a8 repair experience.

I bought my 97 used and it took me two days to finally check every
single feature on the beast.
I found to my shock and horror that two of the 14 ways of the adjustable
seat don't work;
the lumbar lump wouldn't go up and down, nor would the headrest on the
drivers seat.

Luckily the audi dealer where I bought my other audi remembered me and
the mechanic let me in on the secret to getting at the innards of the
seat back.

You have to carefully pry the leather out of a groove that is routed
(molded really) in the hard panel in the back of the seat back. I used
a fork handle. Once you get down and look at the end of the leather
you'll see how it's in there- the leather is sewn to a rubber strip that
is shaped like a wedge that crams in that groove to hold the leather
tight. It's real difficult to get it to let go initally, but once it
starts it comes on off.

Then there are two phillips head screws that hold the hard composite
back panel on to the frame, one on either side of the lower rear of the
back rest. You'll figure it out..

Once those screws are out, the panel drops, revealing the cavity inside
of the recaro seat.

In my case, the motors to both the lumbar and the headrest height
adjusters worked fine, only they didn't move anything. The problem in
both cases was the cable that runs from the motor to the geared
regulator units had slipped too far into the motor unit, and became
disconnected from the worm gear.

There is a single 4mm socket head bolt that holds a clamp which secures
the headrest regulator to the seat frame. You have to flex the padding
stuff at the top of the cavity a little to get the wrench on there, then
it is a bit of a struggle to get it down from the tube it was clamped to.
You have to get the headrest disconnected from those black clips in
order to get the regulator out- I used a board wrapped in a towel to
pry the headrest away from the seat back while flaring the clips with a
screwdriver, and it popped up. There are two black nylon wire ties near
the top of the regulator connecting it to that sheet of felt that you
must clip.

Once you cajole the regulator out, you now have to open the gear
casing. Again, this is assuming that the motor works, but no uppy-downy
and you are willing to try to fix the regulator rather than replace it.

Mine was stuck all the way down, so I was able to remove two of the four
screws in that position,
then I had to remove the screw that covers the main gear and a bushing
comes off with that screw. With the gear's bushing and screw off, you
can pry the linear toothed rail plate up and over the main gear a tooth
at a time until the regulator is at the other end of it's travel. Then
you can get the other gear case screws out, finally freeing the cable
housing.

If you are lucky like me, you will see just a teeny square nub of the
driven part of the drive cable almost flush with the housing. If so,
just grab it with pliers and pull about 7 mm out and verify that it
still turns by operating the switch. I used solvent and cleaned all the
grease off the square end of the cable and blew the grease out of the
worm gear square socket in which the cable goes with spray solvent.
Once dry, I used a toothpick to put a teeny bit of steel epoxy in the
square socket so the cable will stay put, but could be forced out if
need be in the future.

Slapped it all back together and bam, it works- parts cost- one half
drop of jb weld.

On to the lumbar thingie..
It's way easier- Just clip enough wire ties that hold that felt to the
frame till you can reach the brass colored metal clip that holds the
cable housing to the black plastic gear head in the middle of the back
of the seat. For me, same story, cable had retreated into the housing,
so I pulled it out some, verified I didn't pull it too much and glued it
back.

If you pull the cable out too far, it will disengage the motor end, so
push it back some. Be sure not to get glue anywhere but where you want
it. Keep a whole roll of paper towels nearby so you don't get grease on
the leather..

Let the glue cure before moving the now repaired functions.
Putting the wire ties back is not as hard as you'd think, hemostats help
alot. The top most ones use rubber o rings somehow, so look at how it's
done before you clip it. I just clipped one of the two top nylon ties
and was able to get to the lumbar thing just fine.

There may be a way to get the cable re-positioned by going at the motor
end instead of the regulator end, but I thought the regulator was
broken, so I went straight to that.

The leather crams in the slot, I haven't put mine back yet, so I don't
have any pointers.\
If anyone cares I'll post some pictures..

I hope this saves sombody some money someday..

Clint
------------------

Follow up email when he sent me the pictures:

Ok, here they are in all their un-edited glory-
Some are weak, like the one of my hand-
I was trying to show the skin that would peel off your fingers if you
cut the top most wire ties-
Cramming the hand up under the padding to get the new tie was painful-
I recommend leaving those top most ones alone, they have rubber o rings
in addition to the nylon ties, so the felt can be moved some anyway, the
o rings give some.

You could also lump the lumbar repair in with the headrest- sad I have
no picture of the lumbar gearbox, but the motor on the right of the seat
in the pictures is the one, and the cable just goes to the lumbar deal
in the middle of the back rest and is held on to the lumbar thing by a c
clip.

_________________________________
Paul Waterloo
01 S8 Black on Black

Lots of Electronic Mods

D2 A8/A8L/S8 FAQ Digest