Noise below cockpit while sailing

[Juan]

Hi guys:

I was wondering if someone has had a similar experience: after motoring for 2-2.5 hours, the wind finally picked up. We turn the engine off and started sailing. Then we started hearing a tac, tac, tac noise below the cockpit. Not sure if it was outside the hull or within the engine compartment. After 10 minutes the sound was gone. The next day, the same thing. We lifted the boat and nothing was there. This seems to happen only while sailing and also only after motoring for quite some time.

Any ideas? Somebody has suggested a problem with the transmission. By the way, should the shift level be in FORWARD, NEUTRAL or REVERSE while sailing?

Thanks,

Juan

[wind dancer]

Neutral or Reverse, never Forward.  I leave mine in Neutral, so the shaft free-spins while sailing.

[tommyt]

I think that your noise will go away if you shift into Reverse after shutting down the engine. What you are hearing is most likely the shaft spinning. I always sail with the transmission in reverse as that was what was recommended and because when I forget I hear your sound. Try it!

[Ralph Masters]

Hurth recommends the shift be in reverse while sailing.
The tic, tic tic often reminds me to shift it to reverse after the admiral shuts it down, you know the rules, rule one, the admiral is never wrong, rule two, if you think the admiral is wrong, see rule one.

Ralph
Ciao Bella

[Ron Hill]

Ralph : The original tags when I got my C34 in 1989 said:
"When sailing or in tow NEVER leave the transmission in "FORWARD" position, as transmission damage will result ".  I have posted a picture of this red colored tag on our web site!!! 
It further states  "To lock propellor shaft put shift lever in "REVERSE" or otherwise in "NUTERAL".
Many racers put their transmissions in neutral while racing!!

Juan : My above post should answer one of your questions.  I'm wondering if your shaft Zn is tight or sliding up and down the shaft?? - that may be your noise as it touches the strut??  or  Your shaft could be slightly bent and in neutral the turning shaft is touching the though the hull pvc pipe?

[Juan]

Thanks for the inputs.

Ron, I don't know the answer to your questions, but if the shaft if vented and touching the pvc, for example, wouldn't be noisy also while motoring? I don't hear anything while motoring..

[Juan]

Sorry, I meant bent!

[tommyt]

Juan,
When the iron genny is running that tic, tic, tic would be a nice respite. No way you would hear it when under power.

[Stu Jackson]

Juan, you can use the "Modify" to correct spelling or remove posts.

Straight from the horse's mouth:

http://www.c34.org/faq-pages/faq-transmission-position-sailing.html

[Michael Shaner]

Juan,

Couple things...transmission in reverse when sailing if a couple tenths of a knot don't matter. If speed matters, go to neutral. If speed really, really matters, get a folding prop. Otherwise, I would think the "thunk, thunk" could be either the cutlass bearing or your shaft alignment. I have a mild "thunk, thunk" in neutral...and honestly, I've been meaning to assess my shaft alignment for some time! I'll get there...I believe +/- .003 is the magic number?

Regards!

[RV61]

Juan,
If I forget to  turn the Key to the off postion and my ignition alarm not working  I hear a Tic Tic or call it a click click  coming from the electronic fuel pump under the head sink. When I had a knock knock sound like some one taping a hammer on the hull my shaft was out of alighnement. When it  just sightly out of alignment I can hear it when sailing when it was further out of alignment I could hear as it was louder when the engine was running. If putting it in reverse stops the noise while sailing you will know its probabily the shaft need some alighnement in previous posts. When you haer the noise again try going into the aft cabin and looking at the log and see if the sound is more pronounced there.  When you were out did you check your cutlass bearing for wear?

[Ralph Masters]

From the "Owners Manual HBW

CAUTION. Idling position of the
propeller: gear shift lever must be
in «O» position. Use the shift
position opposite to the direction
of travel for locking the propeller
shaft, otherwise the transmission
will be damaged.

So I guess if you're sailing or being towed backward you lock the transmission in Forward

Ralph

[Roc]

Juan,
Do you have a PYI dripless shaft seal?

[Ron Hill]

Rick : If the engine is OFF and the key switch is ON, your "ignition alarm" is telling you there is NO OIL PRESSURE !!
The 86/87/88 C34s also had a "starter engage" alarm, but the oil pressure is more important.

That's an important alarm and if it isn't working, I'd strongly recommend you fix it immediately!!

[Juan]

Thanks for the responses.

Some answers: while I did not check the cutlass bearing (it was just a short haul over water), i changed it two years ago...
and yes I have a PYI dripless shaft seal..