In a message dated 96-05-14 00:06:36 EDT, mark@metricom.com (mark noya)
writes:

>Once the vehicle warms up it has a bad habit of going into 4WD at 
>     higher speeds.
>     

Van is in 4 wheel drive all the time.  If it binds up when hot, check if all
4 tires are a matched set.  Different sizes will cause the fluid coupling to
lock up.  This will eventually destroy the coupling and or lots of other
expensive parts.