Cutlas Bearings on SO37

[tony]

My yacht is again out of the water for antifouling and I have noticed that the cutlas bearing is very sloppy. This is the fourth time in two years that this has occured and I cannot get any answers from the agent or Jeanneau.

Last year an independant marine engineer replaced the genuine bearing with another make, but this has also gone in one season, so I am not sure what to fit next, any ideas?.

Also, can anyone tell me if they suffer from vibration problems on their so37?.

[MalcolmP]

Tony

Many reasons for wear on cutless bearings, obviously how much they are used and also how much sediment is in the water I average about 1 every 2 seasons. Clearly shaft alignment is important, but also the type and amount of fouling that grows on the shaft. Prop shafts often get a coralline growth and when this grows in the grooves of the cutless bearing, as soon as you turn the engine over this acts as a very effective sandpaper. If possible the prop shaft should be regularly turned, say every week,

I previously had a Beneteau and there were several different types of bearing material, some had a sintered insert within the rubber, but it was notable that different types had significantly different lives

Malcolm

[tony]

Malcolm.

Thanks for your reply, The shaft was new last season and the alignment checked and a rubber joint was fitted to gearbox / shaft to help with vibration problems. The shaft was clean when it came out of water. The engine did 90 hours last season. It seems that the genuine Jeanneau bearings are very soft rubber and when fitted was not a good fit on the shaft, quite slack, so taken out and another make tried with a bronze casing and much harder rubber. again this has failed in one season. Last year a new prop was also fitted so the engineer is now suggesting having it checked for balance.

Thank you. Tony.

[haffiman37]

A rubber vibration damper at the gearbox may sometimes make your problems worse. One thing though, what kind of propeller do you have? Is the cutlassbearing properly lubricated/cooled by free flow of water passing through. Anodes just in front of the bearing or to close at the back may disturb the water from going through. Another thing that waers out the bearing is letting the propeller trail when sailing, allways put the gear in REVERSE! My bearing has lasted 20.000 miles!

[tony]

Haffiman37

Thank you for your message, I would confirm that the anode was correctly placed and the boat, when sailing, is kept in reverse as suggested. Today the engineer has fitted another make of bearing, the rubber is much harder and it is in a brass outer ring. This one fits the shaft a lot tighter than the Jeanneau bearing, so perhaps this might well last.

Tony

[haffiman37]

You did not mention propeller brand and type and not at what rpm the vibration starts. I you have the standard 2 blade Radice my experience is that above 2.500RPM (Yanmar 28) you do not need to stir your coffee or shake your martini! The factory, Radice, measures everything in inches without decimals! Have your propeller measured and checked, not only for equal pich on the blades, but even area of the blades and static balance!