Have owned our 91 Cat 30 with Universal 25/Hurth, 970 hours, two years. This season I've become worried about fairly loud tapping noise clearly coming from the transmission when sailing in neutral and motoring into dock, ie under light load. Owners manual says it's ok to sail in neutral or reverse; we always use reverse. Engine and transmission have been well cared for by us and original owner so can't imagine any damage. Forum archives have numbers of articles on shaft alignment, damper plate chatter, cutlass bearings, PSS, shaft vibration, but these are not my problem. It is just that sharp Hurth transmission tapping (clicking) sound, at about rpm speed, when sailing in neutral and motoring in light load. Would someone please tell me this is an ok noise, your Catalina has been doing it for years, or where to get mechanics advice. We're in Seattle. Thanks ahead John M.