Hmm, if its the linkage it could be going between gears... I also know nothing about VDubs* I don't see them removing 5th when they rebuilt it but you never know... Jack the car up and check it, have him try to put it in 5th gear and watch the linkage. Hell I dunno, just throwin out some ideas

Does it grind when trying to go in, or when its "in" 5th