Rattle in Starboard engine

[ashrun4fun]

I went to do my freshwater flush on my twin Cummins Marine 6BTA 5.9 330’s (4788 Bayliner) and upon start up (no fresh water yet and engines still warm) I heard this rattle in the starboard engine.  I’ll try to attach a video which pretty clearly has the rattle.  Does this sound like a bearing in the transmission or something in the flex plate or something else?  Any ideas where I should start in pinpointing the source of this “not so healthy sounding” rattle?

After reading deeper when I searched “rattle” in Marine Transmissions, I’m narrowing it down to the rattle at idle.  I’ll go down today and increase the RPM’s and see if it changes…this will be at the dock in neutral though, not under load.  The load sound test will be in a few days.

Any suggestions greatly appreciated.  BTW Motor and gear oil recently changed (last month), and everything appears to be running fine under load. (the sound isn’t loud enough to hear when the engine hatch is closed.)

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[Mike Mason]

Report back once you bump the rpm’s.  if it goes away its most likely gear rattle.  i have it on a previous boat.

 

 

 

 

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