Shaft Coupling

[bobfrost]

About two years ago I had a new Yanmar GM10 fitted by an allegedly reputable yacht company.

There were all sorts of problems afterwards which I thought had been all resolved.

Yesterday the coupling on the prop shaft sheered. Is this likely to be fair wear and tear (only just over 100hrs on engine) or what other reasons are there for it?

Boat now towed into Ramsgate. Engineer to look at on Tuesday. As the shaftv is accessable from cockpit am hoping can be fixed in situ, is this unrealistic?

Grateful for any advice/info. /forums/images/graemlins/frown.gif

 

[pete]

Hi
I have had same engine as this since 1989 with no problems, could be that your engine is out of alignment or perhaps something has fouled your prop.
Pete

 

[bobfrost]

Thanks Pete.

I'm thinking out of alignment might be the problem.

This really would be the icing on the cake.

Having convinced SWMBO that the new engine would be the last 'big' expence am not impressed so far.

 

[steve28]

Bob,
Has it sheared of right behing the coupling ?
If i have a suggestion for a simple solution to the alignment and the shaft problem. It does depend on the type of coupling, if its a pinch type then your ok if the shaft is tapered then your going to have to get a new shaft.
Assuming you have the split coupling you can buy a vetus bullflex and bolt this in line as well, by doing this it will make up for the shaft you have lost and also help with the alignment problem.

steve

ps i have seen a boat where the shaft had sheared and then shot out the back leaving a big hole.

 

[david_bagshaw]

very unlikely to be fair wear & tear, as others have said, missalignment / bent shaft / damage on installation.

may be operation with loose bolts / engine mounts etc.

 

[kandoma]

what did sheer ? the shaft or the coupling ? If it was the coupling, what happend ? did one of the half shells break off ? If that happended, the installer my have used the incorrect size coupling---metric- inch and tightend the half shells and overstressed the material.

(I call them half shells, because I do not know the correct english word for the split connector)

Peter

 

[colvic]

Hi
When you say the coupling has sheared you mean split in to two pieces? Can you pull up the shaft so that the two pieces come together and check that they match OK?

A Bullflex coupling as mentioned elsewhere is a superb piece of kit. On our new engine/shaft/prop fiiting we suffered a rope round the prop that though the engine kept going, the Bullflex stayed together but the heat generated welded the shaft to the coupling.

Check ALL bolts and nuts securing engine to feet, coupling to gearbox etc..

Phil

 

[bobfrost]

Thanks for all help info so far.

Engineer at Ramsgate has lookes at damage. Prop shaft was in two parts with coupling about 50 cm from stern.

Coupling appears to have fractured and then stirred back of shaft around damaging stern fitting.

Needs fibreglassing by boat builder as water is entering at rate of about 4" per day.

Have got shore power so bilge pump (on float switch) should keep boat safe.

Yacht Co who fitted engine looking tonight as have been advised by engineer at Ramsgate to leave it to them.

Question. Have I got a reasonable case that having both fitted engine and prop shaft they had not done a reasonable job and should fix for free?

Do I just bite the bullet and pay the incompetents to fix their work again?

Could I/ should I claim from insurance. Is this covered in policy?

Grateful for advice.

Cheers

Bob

 

[oldharry]

[ QUOTE ]

Could I/ should I claim from insurance. Is this covered in policy?
Bob

[/ QUOTE ]

Probably not covered as such as it sounds as though the job has been botched, but you should certainly contact your insurers to see if they want to be involved - if only because they will carry much more weight in the argument that is likely to follow with the installers. If you have legal representation costs insurance on your policy, their legal department may well be able to help you too, as well as limiting your own expenses.

 

[steve28]

i would approach the insurance company and see what they say, most are very understanding. It would be sensible to get some quotes for the repair and make sure you also include a flexible coupling like the aquadrive or the bullflex. At least if they agree you will have a subtantially better setup and you will only lose your no claims.

steve