I have never had a 'chatter' problem with Sachs clutches in my shop. Of
course, the flywheel is always resurfaced (unless by some fluke it is
perfect, which is very rare), and if the clutch release fork shows even the
slightest wear, I replace it also. When installing the trans, unless you
have a real trans jack, get a friend to help support it while you bolt
things together- any stress on the input shaft of the trans could warp the
disc. Finally, keep things clean, wash off any grease or dirty fingerprints.
Also to remember is that the Vanagon is a 'truck', not a car, and should be
driven differently, i.e. no 'jackrabbit' starts or riding the clutch.

Karl
Westyman Ent.