In a message dated 97-07-25 16:25:55 EDT, demps2@EROLS.COM (David Dempsey)
writes:

<< 1. My locking rear diff. works fine, w/ a short delay before it kicks in
 which I assume is normal.  My question is in regards to the indicator
 lights, there is one for the rear diff. but there are also two others.
 Were center and front diff. locks an option?  If not, what are these
 for? >>

Yes, the delay is normal.  It takes a moment for the mechanisms inside the
differential to line up so that the lock can engage.   The manual says to
drive straight ahead while awaiting the locking operation.  I've found that
if you really do drive straight ahead, there is very little "differential"
action and the mechanisms take quite a while to engage.  Turning the wheel
slightly and driveing in a slight arc will engage the mechanism usually
quickly.

VW made some Syncros with the optional front diff lock, however, VW didn't
sell any in the USA with the front differential lock option.  Some other
countries got them though.  As for the center position, I am told that VW
made some 4WD Vanagons without the Syncro's viscous coupling, but with a
manually engageable connect/disconnect mechanism that was actuated with a
knob in the center position of the diff lock panel.

Regards,
Jim Davis