Noisy Yanmar 2gm Transmission

[Elcapt]

HI,

I have a relatively new transmission in my 22 yr old 2gm. The original was replaced due to bad cone while voyaging. The low speed forward sometimes rattles a bit, but just a few days ago it started a really loud clattering just at idle speed. With power up and 750-1000 rpm or more, it goes away. Oil is clean and fresh and topped up. What causes this? Thanks ElCapt

[perchance]

Check the flex plate/vibration damper.

[Elcapt]

Thanks, will do. ElCapt

[boden36]

Check for anything that could be bouncing around and hitting something when the engine is rough idling. Things such as exhaust system components etc come to mind. Regards, Richard.

[Ex-Calif]

If it was OK after install and this is a new issue:

- Mounting bolts loosening
- Engine mounts loose or worn
- Other engine bay hardware loose

Is it the same in gar as out of gear?

[jjoftheusa]

Originally Posted by perchance

Check the flex plate/vibration damper.

Add the pilot bearing to this list. Don't ask how I know.

[Northeaster]

Does it sound like the drive cones are slipping on the fwd or rev gear?

Does it do it in fwd and rev, or just in one of them?

Do you get the good "clunk" when you shift from neutral to fwd or rev?

[perchance]

As a point of general interest, long periods of idling the diesel in your boat is extremely hard on the flex plate.

[alelogman]

Agreed, I'm not that experienced but learned that idling is not good at all.