Issues After Cutlass Bearing Replacement

[Rhian]

Hi All

This is my first post, so I'll take the opportunity to introduce myself if that's OK! I have been sailing since my teens in the Solent, UK but in 2011 my husband and I sailed the Atlantic and have been cruising the Caribbean since then. We plan to visit Puerto Rico this season and the east coast of the US the following year. Our 473 is called 'Beyzano' and we have owned her since 2008 www.beyzano.com

Our Issue
After replacing the rubber cutlass bearing on our Beneteau 473, which involved removing the prop shaft and dropping the rudder, we are experiencing new issues.

We now have a high pitched noise and vibration when motoring at low speed and when sailing at over 6.5 knots, we get the same noise. If we lock the prop then we simply get a resonance in the shaft which is just as noisy.

Just for information - we have a Volvo 78 hp engine.

Any thoughts or suggestions would be very welcome.

Many thanks


Rhian

 

[Rich Stidger]

I can't answer your question, but WELCOME ABOARD!! This is probably the finest sailboat forum on the 'net and I will be willing to bet that another sailor will post with your solution.

You will find a wealth of information here and lots of members willing to share.

 

[Rick I]

Check the water cooling to the shaft log.

 

[Anonymous 121765]

Rhian,

I like what Rick offered. That being said, we really don't have enough info to discuss your problem.

Add some more detailed info to these questions for better answers.

Here are my questions to you at this point:

1. what type of shaft seal do you have, wet packing type or waterless?

2. I have a Catalina waterless shaft seal, I do not know what you have.

3. Better made boats like a Beneteau, I would think the shaft is offset a few degrees so as to have clearance & NOT have to drop rudder to remove shaft. You would need to contact Beneteau to confirm this.

4. In neutral, up the throttle to hear the sound per RPM's of the engine, is the sound at your stuffing box or does it sound aft of this?

5. If the sound is aft of this, when removing & replacing the shaft, were you there to witness the operation?

6. Is it possible that the shaft was bent, the cutlass bearing housing bent askewed or, did the engine to shaft alignment change? It only takes a few degrees.

This is why we need more info. After this is done & fixed, I would suggest when in the boatyard from now on, micro manage your project. It's your money & sadly when things go wrong & you are not there to witness it, it becomes YOUR problem & $$$.

See if you can add more detailed info pal,

CR

 

[Rhian]

Thanks for your response and here is some more info.

The shaft seal is a PSS, not a packing type but with a water feed to it and not the usual Volvo seal.

The shaft is not offset so the rudder always needs to be removed if the shaft has to come out.

In neutral it doesn't make the noise unless sailing and the prop is spinning.

Unfortunately we weren't there to witness the shaft removal or any of the re-assembling. We have asked the engineer to explain their procedure and not had a reply yet.

The shaft wasn't bent but it is possible they didn't put it back in the exact same position. We continue to investigate!

 

[Meriachee]

The PSS needs to be immersed to operate. If you remove the hose from the breather tube on the carbon ring, you should get water coming in. (Fast actually, so be ready to put the hose back on) If this is an older PSS that does not have a breather tube, you very likely have an air bubble up there and the carbon ring is running dry, and that would make a noise not unlike what you're hearing. If it's an older PSS, and the tube was not bled when the boat was refloated, chances are that this is the issue. But more important if this is the issue, continued operation with the ring not water cooled, will kill the ring really fast.

Which version do you have?

 

[Tom J]

You don't mention whether the engine and prop shaft were re-aligned after the cutlass bearing was replaced. This is essential after this kind of work has been on the propulsion system. It is even a good idea to check the alignment occasionally, because normal wear and tear will change the alignment. I had some weird noises and vibrations on my Catalina this summer, and after I re-aligned the prop shaft, she purred like a kitten.
If the PSS checks out OK, I'd ask the engineer if they did an alignment.

 

[Tom J]

I should add that the alignment should have been done with the boat in the water, not on the hard.

 

[Rhian]

We have a PSS with the breather tube and yes, water is coming into it.

We have asked the engineer a couple of times to explain how he performed the re-alignment but no response. It was done on the hard. We found a couple of marks on the phalange and gearbox but they were not aligned. They are now.

A different engineer just checked it all this afternoon and thinks there might be a slight mis-alignment of the engine with the shaft, causing it to pinch the new cutlass bearing. He thinks a few more hours motoring might cure this, otherwise the boat has to come out of the water to have it all re-aligned.

Thanks for your comments. I will post again if the problem is cured in the future.

 

[Meriachee]

In a perfect world, the alignment would be done floating. That might explain it.