For those of you experienced with the internals of the vanagon starter:

When doing my engine conversion, I had my 1990 Westy starter rebuilt.  In
the year the project languished, the starter lay unused, and the rebuilder
retired.

Increasingly, (about 50% of the time) the starter spins up, but does not
engage the flywheel.  Naturally it never did this before the rebuild.  I
removed it once, and took it in to another bosch shop.  They bench tested
and gave it back declaring it fit for service (they didn't energize it more
than once I would guess).  So before I remove it again and bring it in, any
thoughts?  My guess is that despite being freshly rebuilt, I now have a bad
final drive.