'89 200q center diff question, more info

[James Marriott <marriott@micron.net>]

Haudi,

Below is a re-post from a days-old message. I've added a little more
detail IN ALL CAPS.

tia,
James

************************************************************

Haudi,

Details:
'89 200q, ostensibly a K26 unit
VIN WAUGC0441KN004273
Build date 5/88
Previous owner ruined tranny by driving with failed clutch. Replacement
installed at (Audi) dealer where I bought the car.
w/o a Bentley, I couldn't find SerNos and such on the transaxle. It does
say "BDE7" and "12 10 89" on the lower left side. I'd guess this might
mean it was built on October 12 of '89? (think euro dating customs)
The cat is pretty much solidly in the way, but I couldn't see (with
lights, mirrors, etc) any of the diff-lock type equipment on the right
side like the 4kq has.
ON TOP OF TRANNY, NEAR #5 SPARK PLUG, "ADZ12060"
ON RIGHT SIDE OF TRANNY, ~CENTERED VERTICALLY, LONGITUDINAL POSITION
UNKNOWN, IS A TWO-WIRE CONNECTOR THAT ISN'T HOOKED UP. DIFF-LOCK SENSOR?

The questions:
With the rear on a jack, and letting the clutch out in first, why won't
the car try to move? It twitches a little, unlike the open-center 4kq,
but it sure doesn't move. Aren't t*rs*ns supposed to work in this
situation? That is, shouldn't it have tried to drive off the jack?
What's the PN or whatever of an open-center 5kq diff, and of the
t*rs*n-center 200q, and what's the physical location of same?

Inputs/outputs/bias ratios/etc?

tia,
James
'89 200q, androgenous?
'87 4kq, clearly has a pair of opens
'86 4ks, serious lack of differentials