Hello guys,
maybe I found the mistake!
Recently wanted to fit the new release bearing before getting the gearbox to my mechanic once again. Sprayed some brake disc cleaner to the shaft for cleaning it first. When I wiped it away I recognized the clutch fork was loose!
As I mentioned the upgraded arm had not the right sized thread for the original bolt DBM588L. Regardless I screwed it in with force until it stuck. But there were about 4-5mm gap from the bolts head (and washer DBM589) to the fork.
Removed the bolt, integrated a few washers and fixed it once more. Now the fork sits tight on the arm and doesn't move any more (except the arm moves her, of course).
Greased the shaft and mounted the LuK release bearing.
Well, now I don't have the heart to mount the gearbox yet. Can a loose fork cause these issues? If so, this was a case of "a small leak can sink a great ship".
Regards
Christof