In a message dated 97-10-14 08:20:50 EDT, bayer@SYBASE.COM (Dave Bayer)
writes:

<< does anyone know a nice and relatively safe method of verifying
 the front diff/VC are working? >>

Find a flat, open surface like a parking lot and jack up one rear wheel with
a floor jack from behind so that the floor jack's wheels are parallel to the
van's.  Jack it only enough to get one wheel barely of the ground.  Start the
van and ease it forward slowly.  With a properly functioning VC, power should
be transfered to the front wheels and the van will move forward draging the
floor jack with it, or will pull itself off the floor jack.  Be careful.  Not
exactly a "nice" method, but it works!

Good luck,
Jim Davis