[s-cars] Subframe bushings- REPLACE- Help!

[Mike Fitton]

This is how I did my 95.5 S6.  If your car is different from mine, you 
should have bought a 95.5 S6.

First the front.  In addition to the mounts, you'll need the following:  
Two bolts in M12x1.5x150 10.9 (Audi p/n N 904 563 02).  Two bolts in 
M12x1.5x105 10.9 (Audi p/n N 905 834 01).  Six bolts in M10x1.5x40 10.9 
(Audi p/n N 905 677 01).  Good luck finding those anywhere other than 
the Audi dealer.  They were only a few bucks each, so I recommend just 
getting them there.  Now, head over to www.boltdepot.com and pick up 
some M12x1.5 nylon locking nuts.  You'll thank me shortly.  If you're 
concerned about the stretching of any other hardware, replace that at 
your discretion.  One can of PB Blaster or equivalent.  You'll also need 
a sucker, I mean friend, to help you.  Having four hands was invaluable.

Remove your carbon-kevlar weave naca-ducted bullet-stopping 
downforce-generating bellypan (heh).  Spray PB on everything you see 
mentioned here.  Disconnect the nuts that hold the transmission mounts 
to the subframe.  Disconnect a couple things (can't remember what 
exactly) at the front of the subframe...they're not major components, 
just stuff to get out of the way.  Remove the ball joint pinch bolts 
from the struckles (I found it easiest to take the swaybar and control 
arms out with it rather try to seperate it all).  Loosen, but don't 
remove yet, the front subframe bolts.  Loosen, but don't remove yet, the 
long bolts at the rear of the subframe that pass through the inner 
control arm bushings.  FWIW, one of mine was totally siezed and I 
screwed up the rubber part of the original mount pretty bad...it didn't 
concern me because I was going to replace it.  You should be able to see 
some grimy 12-pt bolts in the vicinity of that rear subframe bolt...two 
aft of it on either side and one fore, right in the middle.  There's an 
access hole in the subframe to get to that one.  Loosen all six of 
those, three on each side.  Make arrangements to keep the subframe from 
falling on your face.  Take out the two bolts at the front and the six 
at the rear in whatever order you feel is appropriate.  Subframe, 
control arms, and swaybar should all come out as one unit, unless I 
(you) forgot something.

Now that your subframe's out, it's time for the old mounts to come out.  
For the fronts, I used a press in a very non-precise way.  You might be 
able to use a hammer or something as well.  They absorb an awful lot of 
vibration, so maybe not.  Use whatever you have, but a press will make 
very quick work of it.  For the rears, you might be able to just turn 
the old mount off the bolt without removing the bolt.  What I'm getting 
at is being careful with removing that bolt.  There's a sleeve running 
down the middle of the inner control arm bushing that'll ruin your day 
if it gets damaged or misaligned.

Okay, so the old mounts are out.  If your subframe is rusty, hit it for 
a few minutes with a wire brush or something and throw some primer on 
it.  Find some way to entertain yourself for thirty minutes or so while 
it's drying.  Be creative.  Don't just waste it on video games or 
masturbation.  Do that quick oil change while the car's up in the air 
and your carbon-kevlar bellypan is off.  Scrape the brake snot and CV 
grease off the inside of your wheels.  Okay, all done.

Carefully run your new 150mm bolts up through the control arms and 
subframe.  Turn the new mount onto them.  Recommend against loctite 
here.  If you ever have to take it off...well, steel bolts, aluminum 
threads, et cetera.  In fact, we might be adjusting here in just a 
second, so definitely no loctite.  Install the front four aluminum 
clamshells.  They may go in easily or they may require some coaxing.  If 
so, recommend starting with a rubber mallet and working up from that.  
Get em in straight.  Aluminum doesn't like being screwed around like a 
Congressional Page (too soon?).  Hopefully there will be at least a 
little resistance so they won't fall out when you start test-fitting the 
subframe.  If not, maybe some masking tape or something.

Okay, get it approximately into position under the car.  At this point I 
think I'd refrain from hooking the ball joints back up, tempting as it 
sounds.  Basically, here's the idea, and I'll let you decide how exactly 
you want to accomplish it.  You need to get the front bolts at least a 
little threaded so the front of the subframe is properly located.  Then 
you need to adjust the rear mounts, if necessary, so that the six 
smaller 12-pt bolts will line up correctly in the frame.  That's why I 
said not to tighten the rear mount quite all the way down.  Once those 
six bolts are located and it looks like everything's straight, tighten 
the 150mm bolts down until they're snug, or maybe a little bit more than 
snug.  You got those M12x1.5 nylon nuts for a reason...here's the 
reason.  I personally don't trust aluminum threads to hold up.  Maybe 
they would have and maybe they wouldn't.  We can go back to arguing the 
merits or aluminum versus steel someday, but when the parts were sitting 
in front of me, I decided to put a steel nut on the end of the threaded 
aluminum tube.  Obviously, you can't tighten this nut with the subframe 
installed in the car.  That's why you located the rear mounts before you 
lock them down with that nut.  Put loctite on the nut if you like.  I 
chose not to since they're nylon, but in retrospect I probably should 
have anyway.  Okay, rear mounts are solidly attached now.  Put the 
subframe back in for the final time and bolt it down.  This paragraph 
took me about two hours.  Just be patient and use mechanical advantage 
whenever possible so you don't get tired.

A quick note on the two original 150mm bolts you pulled out of the rear 
mounts.  The stock rear mounts have a disfigured thread at the end to 
lock them in place.  I'm sure there's a more technical term, but I don't 
know what it is.  If you decide to throw caution to the wind and reuse 
all the original hardware, I cannot emphasize strongly enough running a 
12x1.5 die over the bolt to straighten out the threads.  You will 
seriously damage and compromise your shiny new mount when you stick that 
screwed up bolt in.  If you also choose not to do the additional top 
nut, you'll probably regret it.

Another interesting thing I noticed...  The 105mm and 150mm bolts the 
dealer gave me were 5/8" hex head, not 17mm.  That was kinda weird.

Okay, bolt all your junx back up and you should be good to go.  
Hopefully I didn't forget anything.

Now the rear.  This is definitely more complicated than the front, but 
it took me less time.  The rear subframe is held on with nuts on studs 
attached to the body, like normal-people wheels.  Be careful not to 
damage the threads on these studs or you'll just wind up crying yourself 
to sleep.  I recommend four new M10x1.5 nylon nuts here as well, with 
four corresponding washers.

Start by disconnecting all the incidentals.  I can't remember exactly 
what all is back there, but there's some stuff.  I definitely recall 
some clipped in hard lines, so don't break those.  Remove the nut on the 
bottom of the diff support bolt.  I seem to recall this being a 
nonstandard 15mm nut.  You should probably support the diff at this 
point too.  Yeah, that's a good idea.  Disconnect the upper control arm 
at the subframe.  I didn't find it necessary to remove it completely.  
Disconnect the mount holding the front of the lower control arms to the 
body.  Disconnect the inner lower control arm mount from the subframe.  
I don't have a rear swaybar, so if you do, you're on your own for that.

Okay, that should be everything.  If you're willing to disconnect the 
exhaust, it would be extremely helpful.  I wasn't willing to, due to 
rust and general previous bad luck with exhausts, and I was able to 
wiggle the subframe out around it somehow.  It took a while, but 
probably less than removing the exhaust would have, so...your 
discretion.  I think that's everything, so remove the subframe.

The stock mounts for these are a little weird.  Audi doesn't sell them 
separately, indicating to me that they're not designed to be replaced.  
I think you're supposed to by the whole subframe with the mounts already 
installed.  However, that's not to say that they're forever attached.  I 
pressed out the rubber part first, leaving the metal sleeve.  If you 
have a press and feel you can get a socket on the sleeve just right, go 
for it.  Otherwise, just punch out the rubber part and remove the 
sleeves after the fact.  I used a flathead screwdriver and hammer.  
Another option would be to cut a relief in the sleeve with a hacksaw, 
but that would probably still involve a flathead and hammer.  Use your 
imagination.  You don't need any of this crap and I'm sure you'll want 
it to go in the circular file as soon as possible.  The subframe isn't 
soft aluminum so show no mercy.

Once the old mounts are out, do some more primer action if you like.  
This time, take pictures of your ridiculously goofy positive camber and 
try to use them to get a free alignment someday.  I found the new mounts 
on the rear pretty tight compared to the front.  I think on a few 
positions I actually wound up using the press.  It was against my better 
judgment but they went in easily in the face of Mr. Bottle Jack and 
weren't damaged.  What's all that churning and bubbling?

Maneuver the subframe back into position and bolt it up.  This time, 
installation is pretty much reverse of removal.  When reattaching the 
lower control arms, you'll be fighting the bushings a bit.  I believe I 
did the front mounts before the inner mounts, but do whatever you feel 
is best when you're under there.  I believe you're technically not 
supposed to torque any of those mounts down with the car in the air due 
to preload issues.  I didn't think about that at the time and I haven't 
shot any bolts out to my knowledge.

Go back and torque everything again, including the stuff you forgot.  
Make sure it looks straight.  If it doesn't, there's probably a reason.  
Sorry, I don't know the exact torque specs for most of these.  And shame 
on me for just winging it, but that's what I did.  When I get a torque 
wrench I trust, I'll go back and check everything, but until then, my 
car's still holding together.

Go for a drive.  Dig the way it suddenly makes your five rubber luxury 
car diff mounts feel like warm turds as you get on and off the 
throttle.  Buy your sucker/friend a hot, classy meal at Denny's.  Spring 
for the milk shake.  Flirt with the waitress.  Go home and sleep for 14 
hours.

-Cheers!
Mike Fitton

brian bilotti wrote:
> Guys,
> In the vain of the the ABYSS, I'm going total AMD
> aluminum sub mounts. Never done these before.
>
> Any BTDT's, hints, tricks???
>
> Just wanna avoid a big bill and bloody knuckles :-0
>
> Thanks as always :-))
> bb
>
>
>  
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