Port side cutlass Bearing "chirp"

[Top Shelf]

Well it 's time for Top Shelf to come home from San Sal. But the last time out deep dropping down here I could hear the port shaft chirp or sing when I go in neautral. Now this is a new problem and when I went under the boat to check it out everything seemed fine. I can recreate the chirp as I turn the wheel by hand. Both wheels turn as they normally do and there wasn't any appricable growth on the leading or trailing edge of cutlass bearings and no drag. They're clean and I didn't really see any indication of subsatintial wear.

As soon as I'm making turns the squel or chirp goes away. It's only when I go into neutral. I've got about 400 KM's ahead of me. Think this is a big issue, has anyone run into this? I didn't find too much searching the threads. Thanks.

 

[Boatsb]

First be sure it's the cutlass bearing not something else like the packing gland. If the bearing has no play and the shaft turns the is little lube running ( water) on the surfaces so it may be the issue. When it reaches a greater RPM like in gear it has enough lube to run without friction.

If you are not hauling out before the trip do the best you can to really push up and side to side on the shaft to see if there is any play. It could just be an annoyance like brake squeal.

 

[Captned]

Funny, I have noticed I'm getting a "Whistle" or "Chirping" out of my drive train when I go to neutral. What the hell could it be?

Not to hijack your thread..... Ummm, good bloody mary....

Captned
MBMM

 

[REBrueckner]

I could hear the port shaft chirp or sing when I go in neautral. Now this is a new problem and when I went under the boat to check it out everything seemed fine. I can recreate the chirp as I turn the wheel by hand..

you means it chirps as it's being put into neutral?? but not while in neutral?
does not sound like either cutlass nor packing...if the packing is cool or barely warm and not leaking its ok' if you can't yank the shaft to and for in the cutlass it too is ok...it's almost impossible to hear a high frequency sound from underwater.....
almost certainly the sound you hear is from the transmission or engine...could it be a fan belt echoing..where are you when you hear the sound....at the helm??

Is engine onor off while you "recreate the chirp"...whichever, it is try the other and I am guessing you will not hear the chirp....if that's correct, it IS the tranny or engine..

 

[Nonchalant1]

My sb shaft/prop "sings" at going in and out of neutral when the prop is still turning. I can hear it stop as the prop stops free wheeling. When it goes into gear, it will sing briefly at very low speeds, then it goes away. When it's hauled and still wet, I can not duplicate the sound. I thought maybe it was rub between the propspurs cutter and bearing, but it appeared not to be when I watched when hauled, but you can't duplicate the prop's forward pressure of moving the boat when it's on the hard. At any rate, mine has been doing it for 7,000 NM with little change, so if yours is the same thing, I would not worry about it.

Doug

 

[Brian Degulis]

Doug yours sounds like prop squeal. That usually comes in at very narrow RPM band and goes away when RPM is higher or lower. It can appear out of nowhere it's a hydrodynamic phenomenon a little growth in just the right spot or some minute change in prop shape can cause it. It's harmless nothing more than annoying and you can get rid of it by having a prop shop put a squeal edge on your props.

As for the original poster if your saying you can rotate the shaft by hand and make it squeal I can't see how that could be prop squeal at such a low RPM.

Brian

 

[captddis]

generally a squeal is a cutless bearing that is dry or is being squeezed on one spot by strut mis alignment. As long as the noise goes away, I would not loose any sleep. The prop hum is usually a hum or whine.

 

[SLIDELLBIGAL]

One or Two piece Shafts??? Could be the shaft joiner getting loose.

 

[Top Shelf]

No, single piece shafts. And like I said I could recreate the chirp as I turned the wheel underwater. We're in Nassau now and guees what, no chirp as the wheel slows and stops. I think we're good for the blance of the trip.

But I will get under the boat again and really try to figure out what gives. Been 4 years since the cutlass bearings were replaced, so maybe it's time again. Thx.