Besides checking the system for wear and play, the friction damper on the hub is there to calm the shimmy you have experienced. The friction damping is between the bronze/brass plate and the top surfaces of the hub. If these bearing surfaces are well lubricated then this reduces the friction that you actually need. You will get more friction from that damper by running it with just a smear of light oil, that might be enough to control the shimmy.
https://sites.google.com/site/morganatica/70-modifications/vw-hydraulic-steering-damperRegards PJB.
