tranny problem

Hey Club SeaRay, I have a 02 380 Dancer w 8.1's that has a loud clatter in the port side tranny. the noise is definitely worse in reverse, about 50% as load in forward, and no clatter in neutral. You can feel a definite vibration through the casing. Has anyone else experienced this...

I have twin 4.3 mercruisers, yesterday i was at apporximately 3000 rpm and the starboard engine tranny seamed to slip, when I brought the rpms down a little I felt it engage again. Could this be checked while in the water? I cannot trailer it. Could it be something simple? can I still use it...