Shaft issue-gctid820848

[iceclimber]

After running a bit then slowing down I can hear a high pitched sound (more like a rubbing/hum type noise) that winds down with the spinning of the shaft. I'm having the stuffing boxes repacked, I do check those occasionally for heat, and they drip water at a steady rate...probably too much hence the repack.

What else might I need to look at ? It's not doing it in gear at idle, I have to run the boat for a bit.

[Pcpete]

Watch your tranny temps. You may need a fluid change and cooler blow out.

[smitty477]

"iceclimber" post=820848 wrote:
After running a bit then slowing down I can hear a high pitched sound (more like a rubbing/hum type noise) that winds down with the spinning of the shaft. What else might I need to look at ? It's not doing it in gear at idle, I have to run the boat for a bit.

"

An unusual set of symptoms - it sounds a lot like the 'rubbing' only occurs at a specific engine speed and load level. Perhaps something is growing in the fixed stern tube behind the packing flex hose, or the shaft is touching the stern tube under load, or something is able to contact the trans flex plate.

I would watch closely the engine mounts and shaft movement that happens when the engine is put in gear and power is ramped up - near the engine mounts and at the stern tube area. Utilizing a camera to take some video that can be slowed down and reviewed in a convenient place may help a bunch.

[sockeye]

Just a thought but do you have shaft brushes (zincs) ?

We had a similar whine a couple weeks ago .I shut down the starboard engine and the sound

was there .I then restarted and shut down port engine and the sound was gone so i knew it was

on port side .Like you it only happened at certain rpm but it was a high pitched whine ,went away in reverse.

A buddy handled the controls and we went for a short ride in Vancouver harbor ,It was noticeable right away.

Just bent the metal bar (that attaches the zinc to the bonding system) a bit and the sound was gone. Nice

to have an easy fix for a change.My friend who is a commercial fisherman was told to put a little steel wool

between the zinc and the shaft for a better connection.So if you have shaft zincs check it out.

[yachtman]

I had that problem sound once on mine. Although my shaft zincs were tight I got into some seaweed and the zinc slid down and was touching the strut. Moved zinc back up problem solved. Not saying that is your issue though.

[iceclimber]

Thanks Captains, I will check out the shaft zincs let's hope it's that simple. I was thinking Cutlass bearing.

Thanks to the power of dem interwebs as a fresh water boat I see I need magnesium zincs.

[guntar]

Did you do something with the props? It could be prop sing? I currently have similar after I changed props.

[iceclimber]

"guntar" post=821150 wrote:
Did you do something with the props? It could be prop sing? I currently have similar after I changed props.

No, nothing with the props. I did have a funky alternator belt that may be suspect, swapped it out and changed the fluid in both transmissions...don't see anything out of the ordinary. Still waiting for the marina to pack the stuffing boxes. Just hoping it's not a cutlass bearing.