Hello Michael;  I had this problem when I bought my newest Vanagon, what I
did to solve the problem was to remove the instrument cover from the front,
remove the speedo instrument light, put the long plastic hose that comes
with every WD40 can on the nozzle, and direct the spray at the centre of
the   speedo needle.  Don't spray so much that it drools all over the face
of the speedo, just get it in the pivot point, it won't take much.  I've
driven the van nearly 100,000 since then and the speedo has behaved
perfectly.                                Larry Carter