I was successful in repairing two VW odometers over the weekend.  The '87
Vanagon's cast metal gear had slipped off of the end of the odometer shaft.
To my surprise, it fit very tight when pushed back into place.  Anyone had
one of these gears walk of the end of the shaft that wasn't loose?  The
other, on my '89 Jetta was more typical.  The gear was just spinning on the
shaft. I removed the gear and "re-sized" the center hub by sqqueezing it
with a pair of medium sized pliers.   It fit so tightly, I had to work it
several times before it would go back onto the shaft.  When it seemed about
right, I re-assembled the number cluster and forced the metal gear on.
Seemed very tight.  I'll will keep you posted as to how long they last.

                                                                  Jay