In a message dated 97-12-04 09:30:59 EST, vickrail@VELOCITY.NET writes:

<< The lock knob you refer to should be pulled out to engage the AWD. In 11
 years of driving Syncros, I can think of only two times I have had to
 manually engage the AWD. The knob SHOULD NEVER BE PULLED OUT WHEN THE
VEHICLE IS MOVING. >>

This is not correct.  The AWD function is always active and is automaticly
brought into action when the rear wheel speed differs from the front,
indicating wheelspin.

The knob is to actuate the rear differential lock which is not directly
related to the AWD system.  The AWD viscous coupling ties the front wheels to
the rear.  The rear differential lock locks the two rear wheels together and
was an option to most Vanagon Syncros

The manual describes two specific conditions when you should not engage the
differential lock.
1. When traveling on paved roads.
2.) When one wheel is spinning.
It is perfectly acceptable and normal to engage the diff lock while in
motion.  I don't think I'd do it while in a sharp curve though.

Regards,
Jim Davis