The Bentley manual details adjusting the sliding door. The top roller is
adjustable, and if yours rattles with the door closed, it probably needs to
be adjusted out, that is, its nut loosened and the roller slid along the slot
in its bracket toward the outside of the bus, then the nut retightened. This
will have the effect of drawing the top front of the door in toward the body
more when closed. The bottom front roller is also adjustable via shims. If
your weatherstrip is shot, you should replace that, too.

David
'65 Bug
'71 Bus