Generations of quattro

[QSHIPQ at aol.com]

Rob Beatty wrote
Whole bunch o stuff chopped....

>Question is....

>Whats Gen 1 and whats Gen II, ie whats the model cutoffs (i'm assuming the
>UrQ is Gen 1, but how about the rest of the Audi line?)

I'll do my best to catagorize this to include most of the subtle differences 
as well as the basics.  Please note this is *USA APPLICATION ONLY* (Europe 
introduced ABS updates on older chassis earlier, the usa never had abs urq's, 
etc.), some M/MY had vin splits on application:

Pre 1984 
Gen IA = early urq's and 4kq's used a single knob, which manually locked both 
the center diffs and the rear diffs simultaneously
1a did not include ABS function

1984>1987 (exceptions Gen 1C)
Urq/4kq/
GEN IB = later urq's and 4kq's used a single knob (2 detents) or rotary 
switch to control the diffs as follows:
Position 1 = center diff on
Position 2 = center and rear diffs on
1B did not include any ABS function

1985-1986>1988
5ktq/5kq/4kq
GEN IC = includes all gen 1B
Positiion 1 = Center diff on 
Position 2 = Center/Rear diff on 
All Gen 1C used rotary style knob, all models
ABS Auto disable when either center or center/rear locked
ABS defeat switch on dash

1988/1989>1993
80/90/200tq/urS4
GEN IIA = Introduction of Torsen center differential, rear locker, 1988 with 
the 80 series sedan, type 44 intro in 1989MY, all UrS4
Center Torque Sensing differential, rear locking differential with 
electro-pnuematic rear actuator with 15mph cutoff.
ABS = Bosch 3 channel
ABS disable with rear differential locked
ABS defeat switch on dash

1989-1994
v8 only
GEN IIB
computer controlled clutch plate center differential (early auto), Torsen 
center (manual and later auto)
Rear torsen differential (all v8)
3 channel abs

**  As of 1994 the rear locking differential was deleted (all models) in 
favor of 2x2 channel electronic traction control (included 4 channel abs) 
with open front and rear diffs**.  Audi also fell to market/liability 
pressure and deleted the ABS disable switch on the dash


1995>1999
S6/A4/A6/A8
GEN IIIA
Torsen center diffential with ABS IV Electronic Differential Locking traction 
control (2 channel only, both fronts or both rears, 40mph disable)
Open front and rear differential
4 channel ABS

2000>
A4/S4/A6/A8
GEN IIIB
Torsen center differential with Bosch EDL version 5.3 traction control with 
Electronic Stability control
Open front and rear differentials
4 channel abs

1999>
TT
Gen IV 
Haldex hydraulic synchro type center locking differential, 2channel EDL and 
ESP 
Open Front and rear diffs 
4 channel ABS

HTH

Scott Justusson
QSHIPQ Performance Tuning
Chicago IL