Rattling noise from bell housing

[Markd52]

I have a 2002 380 Sundancer with 8.1 Horizons. I thought I had something caught on the prop while cruising but after coming to a stop and in neutral the rattling noise appears to be inside the bell housing. It doesn't make a difference if the motor is In forward, reverse or neutral. Someone said it could be a bolt that is coming loose on the flywheel. Anyone ever had a similar problem. Any suggestions would be much appreciated.

 

[Sea Ray Mark]

It's pretty common to have the drive plates rattle but they usually don't start doing it suddenly it's more of a gradual thing. If the rattle goes away when it's in gear with a little bit of throttle (maybe 1000 RPM) that would be another indication of the drive plate. From what I understand there's nothing wrong with them but mine annoyed me enough that I decided to replace one of them.

 

[Jimmy Buoy]

It might sound crazy, but it might be that you need a new set of spark plugs. The 8.1's are known for being hard on plugs (around 200hrs) and sometimes the beginning signs of this is drivetrain rattle at idle. In my case with inboards, the one transmission was rattling at idle so badly that I thought the tranny was shot. A CSR member suggested that the plugs were starting to fail which in turn caused the engine to have a lumpy idle. That lumpy idle was shaking the drivetrain and making the transmission rattle.

New plugs immediately solved the rattle. Amazing!

 

[Gary Hill]

Jimmy's point is pretty common. Plugs, wires, tune tune up type stuff should be looked at.

 

[sdleo26]

Make sure your shaft zincs (if you use them) have not spun loose. I had the infamous rattle, thought it was the dreaded flywheel chatter or plugs, changed plugs and still had it. I was going to change to a hydraulic fluid as this has solved chatter on ZF transmissions, but while I was researching the topic I came across a thread on another forum where the rattle/noise on a sailboat was due to a zinc. I pulled the boat and low and behold it was the zinc slapping on the hull and propeller bore!

Edit : Disregard, I just realized the noise is there while transmission is in neutral.