[torsen] RE:quattro Generations - there are *NO* locking torsens

QSHIPQ at aol.com QSHIPQ at aol.com
Sat Jan 27 13:02:02 EST 2001

The illustrations in both Bentley, ETKA and the microfiche gives the illusion 
that there is a rear "locking" torsen.  This is *NOT* the case.  You either 
have a lockable rear diff (up to 93S4 in the usa) or a torsen rear diff (v8 
all, Scars all from '93).  

If you look at the details of how the diff locks work vs the torsen, you 
could see that a whole 'nother diff locking actuation setup would be 
necessary to lock "over" the torsen (ala VC differential locks).  WR was 
known to use a locking type torsen (more an "unlocking type") in his San Remo 
S1 win.  Before that, most audis race cars used either the torsen, a clutch 
lsd, or a locker.  Peter, there are *no* exceptions.  My own thinking on why 
you see this in both Bentley and parts references, is that audi wasn't sure 
what they were going to use in the rear diffs of various models.

Don't be fooled by any pictures here, there are no known locking torsens 
available in the audi models, all of them, including race cars.

The USA uses the following references:
<1988 manual locking center and rear diffs
88> either gen 1 or torsen center, torsens started with the 80/90 chassis 
first, then went to the 5k/200 chassis by 1989 (rear locker with 15mph speed 
disable introduced with the center torsen intro)
!989>1993  center torsen, rear locking diff (speed disabled).  Exception  V8 
application: center torsen (5spd), electric clutch lock (early auto), rear 
torsen (all)
1994>  Torsen center, EDL rear 

All drawings referencing a locking rear torsen are incorrect as printed.  




Peter B writes:
OK - here is a jpeg of the bentley page - note the [200 models - Quattro]
and the [All Wheel Drive 016 - Rear final drive components].

While the illustration does not show the locking lever, this is shown later,
note that item 15 is labeled Differential lock clutch body and that item 10
is a Toren differential.

I'll send the attachment to you and will forward a copy to anyone on the
list who would like to see it. (please reply with a send copy request)

I think the diagram provides all the explanation required.

Peter Berrevoets
1990 200TQ
Toronto, Canada

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