I think my second drive after about 1000 hours just made this loose nuts in a beer can sound while underway; I took it to Blackmans and they checked it out and said it was OK. It detonated about 500 hours later! My last2 have been quiet (er) I guess, my current one is smooth however when I cut the engine and glide to a paddy I can hear the props and gears turn while in neutral. Like Don always said when I'd ask questions about this kind of stuff - "Just go Fishing!"

Glad your back up and running, Tuba should be back in business by Memorial Day.