Mike-

Check the clutch arm on the top of the bellhousing.  If the bushings are bad,
you can get all kind of neat things there.  It seems to be a fairly uncommon
disease, but it still happens.  It's more common in '73 and later beasts,
aircooled vanagons included.  (Even though they're hydraulic, the fork bushings
love to wipe out...)

Also, check the flexible tube under the tranny.  Is it kinked?  Loose?  inspect
everything.  I had a real similar problem in my '70 camper and it turned out
to be a broken throwout bearing retainer clip.  That *might* be happening in
yours, but I doubt it as they changed the design around '73 to prevent that
from happening.  (They'll run without clips!  You need 'em to hold the bearing
in place until the pressure plate does so by itself, but I've pulled one apart
that had NO CLIPS!)

Best of Luck,

Harris