I have had the starters rebuilt in both of my vanagons and they work
fine.  I am sure that there is a shop in your area that specializes in
rebuilding starters and generators and they would give you an estimate
first.  I used to have a problem where the starter would temporarily
balk if it were warm: cold it was great.  New vanagon starters are
fairly pricey.
Lloyd Perkins  dad@together.net