4000Q Diff. Question

["Guillermo S. Christensen" <gchriste@CapAccess.org>]

How quickly should the differential locks on an '84 4000Q lock and unlock?
On mine, after I pull out the switch to the first detent, the center diff
locks within 10-20 meters of driving; pulling the switch to the second
detent the rear diff takes another 20-40 meters to lock (at least
that's when the indicator lights go on).  After pushing ths switch in to
unlock them, it often takes 100-300 meters of driving before the indicator
lights go off.  Is this normal?  

Guillermo S. Christensen
Mclean, Virginia
'84 Audi 4000S Quattro
'93 BMW 325is