follow up to transmission dead? probably not clutch 89 90q

[Nathan D Engelbert]

I brought my 89 90q home from wisconsin this past thursday using a uhaul
flatbed auto transport and dropped it off at double A mco in skokie IL on
thursday night.  Had spoken with them before, and they said they could
work on it friday.  Well, called them friday after work, they want to
charge me $895 just to take out the transmission and look at it!  I went
down there saturday evening to get a couple of things out of my car, and
it's unlocked!  Also looks as if the aamcoites have gone through all my
posessions in my car.  Had a clutch kit from blau boxed up in the
passenger seat, and it's been opened and parts are strewn about.  Needless
to say, I don't trust Aamco right now.  Well, that's not happening right
now, and I'll be having my car towed elsewhere.  I'm debating just buying
a used transmission and doing the swap myself. 

Just to recall, the symptoms were, driving down road about 55 mph when it
feels like someone taps brake a couple of times within a mile.  All of a
sudden I can rev my engine and get no response.  Take it to a shop in WI
and they tell me it's not the clutch, and that they don't want to tear
apart an audi.  SO, list tells me that it's probably either the torsen or
the input shaft to the transmission.  The car is now making horrible
grinding noise when engine is running with clutch depressed or not, in
gear or not, etc. but the engine runs fine.  The car was towed from my
father illegally parking it two wheels up last fall, with what seemed to
be no ill effects.  Also after breakdown it was towed same way.  I know
that this is BAD.

My questions are (as my bentley is in my car at aamco):

1)  Are the transmission and the torsen all part of one big piece/in the
same housing?  If I were to buy a used transmission, could i get both?

2)  With what degree of certainty is it the torsen or the input shaft?

3)  Is it worth it to have the car fixed, have the transmission/diff
replaced, just start looking for audi #2?

4)  How much of a pain is it for one to swap transmissions in this car?
I'd be replacing clutch as well, what are the chances that it's something
else and that this wouldn't fix it?

5)  I believe Aamco is being unreasonable, am I right in this opinion?  I
have a friend in dayton, OH that had his ford ranger's tranny taken out,
looked at for $300 at a local place, and syncros replaced for another
$200.


TIA for all help,

Nathan Engelbert
89 90q (slowly dying)