Ever since I bought my Vanagon, a @3 years, I have had a problem with front
wheel weights being thrown off shortly after balancing.  After 60 mph the
vibrations would start.

After I replaced my front ball joints, replaced my front rotors and bearings
and rebuilt my calipers, I no longer have any vibrations: even at 80 mph.  I
have not even have the front tires rebalanced.  I now suspect that when a
brake shop replaced the rotors for the PO, they did not seat the bear races
fully OR the American rotors were not machined correctly causing the problem.

So if you are having vibration problems and you might want to check that your
bearing races are fully seated and the bearing races in the rotors are
machined correctly OR just buy some new GERMAN rotors from the BD or your
favorite Flaps.

Robert