My Dufour 31 is built in 1979. I have hauled out my boat in March when I was purchasing it in Seattle. All seemed OK with no clearances apparent. In any case (with my limited engineering knowledge) I do not think there should be any vibration due to lose shaft / worn out bearings when the engine is in neutral and shaft not turning. I spent my holidays working on interior,renewing cushions and building that instrument housing to relocate my nav instruments so had no time to look into engine. I plan on hauling the boat sometime in March when I will look into this one as well.