[C320-list] Transmission or prop noise

[Jeff Hare]

I'd suspect the prop leading edges still.  I *think* they should be blunt/rounded or flattened and *not* filed to a fine edge but others will correct me if I'm wrong here. 

The cones don't slip once engaged, so unless its bearings in the transmission that's not where I'd look. 

If you can only duplicate it under way in forward I'd suspect the prop. 


------Original Message------
From: Chuck and Kathy Mueller
Sender: c320-list-bounces at lists.catalina320.com
To: c320-list at lists.catalina320.com
ReplyTo: C320-List at Catalina320.com
Subject: [C320-list] Transmission or prop noise
Sent: Oct 24, 2010 4:31 PM

This year, I developed a noise in the drive train.  It's a high pitched noise at most engine rpm's, but it goes away at low speeds and at high speeds.  I'm hearing it in forward at about 1500- 2800 rpm, when motoring.  I can't duplicate the noise if Irun the engine up in gear when tied to the dock.  I've checked alignment and it is very good.  I thought that this might be prop harmonics from my three blade fixed prop as I cleaned the prop last spring, but I don't really have any rounded trailing edges per the post a few months ago.  A neighbor told me that the Yanmar (Kanzaki) transmissions can do this due to wear of the cones.  Anyone have any experience with transmission noises?
Chuck Mueller
C320 - 2000
Northwind #676