Re: Prop shaft bearing

James Alton


   Really sorry to hear about the vibrations and the new oil leak.  I am not sure that a failed stern tube bearing would cause the amount of vibration that you are reporting, especially under sail?  I have run a boat once with a completely failed  stern tube bearing and while it was noisy the vibration was not terrible.    Did you try pulling and pushing sideways on the shaft to see if there was any noticeable play when you checked the prop?  Do you know if the balance was checked on the 25CM pulley that you installed?  You might also check the run out on the shaft near the coupling with a last word type indicator while rotating the shaft by hand.  Or based on how bad the vibration is you might just place a straight edge close to the shaft near the coupling and rotate it.  The run out might be bad enough that you can see the gap opening and closing as the shaft is rotated.  The only other thing that I can think of would be that the faces of the sides of the pulley you installed were not perfectly parallel.  You could check this by removing the coupling bolts, checking the alignment and then rotating the pulley 180 degrees and measuring again,  you should get the same readings of course.  I hope that you find the problem,  best of luck.

   Thanks to the Sharki #1 owner who reports that he has never had vibrations with his Amel alternator setup.  I am very anxious to set this up on Sueno ahead of the Atlantic crossing.


SV Sueno
Maramu #220

On Mar 2, 2019, at 8:00 AM, Rainer Huthmacher via Groups.Io <thelastoneever@...> wrote:

Thank you all for the feedback,
Unfortunately it’s not the alignment, which would have been quite easy to fix, nor the engine feet. The problem started after I installed a prop shaft alternator with a 25 cm pulley on the shaft. To do this I had to move the prop shaft 2cm to the back. Since then I have a dripping Volvo shaft seal , heavy vibrations under power or under sail and whistling loud noise over 2000rpm or if I sail over 6knots. I removed the alternator again, but noise and vibrations are still there.
I checked the prop but it looks fine.
I had several mechanics look into it (which I usually never have, as I do everything myself), but none could tell me for sure what’s wrong.
So I only can imagine my shaft bearing is failing after almost 40 years.
I would hate lifting the engine, as the Sharki has not an engine room like the SM, and I’m afraid it’s gonna take me much more than 6 hours as it would take Joel Potter😜
My idea now is to manufacture a tube split in half which would fit exactly around the shaft and try to hammer the bearing out from the inside...Anyone ever done this?
Thanx already 
Rainer Huthmacher, Sharki Rock’n Roll

On 2 Mar 2019, at 05:04, Giorgio Ardrizzi <giorgio.ardrizzi@...> wrote:

I have been using the shaft alternator for 30 years on my Sharki (#1 - 1980) and I've never had vibrations, just a little bit of belt noise.
In 2008 I replaced the Perkins 4108 with a Yanmar 54 hp and I also changed the propeller shaft and adapted the alternator that continues to go very well despite its 40 years of life
Maybe yours is an alignment problem.

Il Ven 1 Mar 2019, 15:05 James Alton via Groups.Io <> ha scritto:

   To those that have used the Amel  shaft generator on their straight shaft Maramu or Sharki,  do these tend to cause shaft vibration or was there just some problem with Yin Yang?  The shaft drive pulley was removed from my boat before I bought it and I have been planning to reinstall it this summer.


SV Sueno
Maramu #220

On Mar 1, 2019, at 11:08 AM, Steve Leeds via Groups.Io <yachtmaccabee@...> wrote:

You may want to check your shaft alignment.

Steve Leeds
Sharki #121

On Friday, March 1, 2019, 6:06:47 AM EST, Rainer Huthmacher via Groups.Io <thelastoneever@...> wrote:

Hello Captains of Amels,
I have to change the cutless bearing of my Sharki, because of vibrations under engine wich occurred after I was installing a shaft alternator...
How do I pull the propshaft?
Do I really have to lift the engine?
Any suggestions of a Sharki, Maramu or Mango owner would be greatly appreciated....
Rainer Huthmacher
Former owner of SM#69 “Yin Yang”,now owner of Sharki#83 “Rock’n Roll”,currently in Teneriffe...
It feels good to back in this great forum

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