[C320-list] Transmission Drive Flange Bolts Fall Out

[Ken Geiger]

Not on #765.  Maybe they should be.  But drilling onle the bolt heads to wire would not keep the nuts from loosening.

I'm hoping someone can take a look at their application to see if there are better solutions or upgrades.

Ken

 

 

 

---- Original Message ----
From: Chris Burti <clburti at gmail.com>
To: 320 <C320-List at catalina320.com>
Sent: Fri, Aug 14, 2015 12:59 pm
Subject: Re: [C320-list] Transmission Drive Flange Bolts Fall Out


I'm going from memory, but aren't those bolts drilled for safety wire?

On
Mon, Aug 10, 2015 at 1:24 PM, Ken Geiger <kendgb at aol.com> wrote:

>
>
>
Northern Dream,  hull #765 is a 2000 year build with a Yanmar 3GM30F
> engine
s/n E25479 with Marine Trans
> (from an old Survey) .
>
> Trans S/N and other
info not known but I can update that when next aboard.
>
> I have pictures of
the nuts and bolts for those interested.
>
> Ken
>
>
>
>
>
>
>
>
>
>
---- Original Message ----
> From: Chris Burti <clburti at gmail.com>
> To: 320
<C320-List at catalina320.com>
> Sent: Mon, Aug 10, 2015 12:38 pm
> Subject: Re:
[C320-list] Transmission Drive Flange Bolts Fall Out
>
>
> Ken,
> Engine,
transmission and Hull Number info would be helpful...please
> share.
>
>
Thanks,
> Chris Burti,
> Commitment, #867
> Farmville, NC
>
> On Mon,
Aug
> 10, 2015 at 9:51 AM, Ken Geiger <kendgb at aol.com> wrote:
>
> > A few
days ago
> while motor sailing we heard a low vibration sound.  While
> >
continuing, I
> inspected the transmission output area and at first saw
> >
nothing shaking but
> then observed 2 bolts laying on the floor under the
> >
drive flange.
> >
> > We
> stopped the motor and I found 3 of the 4 bolts had
fallen out and the
> > fourth
> bolt was loose with the nut still attached.  I
found all the nuts
> > bolts and
> washers under the engine and replaced them
and got back under way.
> >
> > Later
> at anchor I removed each bolt and
nut, cleaned and re tightened with
> > some
> blue loc tite that we had on
board.
> >
> > The 4 bolts were M10- 1.25 x 33 mm
> long except 1 was 35 mm
long. The bolt
> > used a 15 mm wrench and the thin nut
> used a 17 mm wrench.
The bolt head
> > had a #7 forged on it.  There was a lock
> washer used but
placed under the
> > bolt head. On auto applications these nuts
> and bolts
would be high strength
> > and perhaps these are as well.
> >
> > I
> intend
to investigate replacing the above coarse thread with M10-1.0
> > fine
>
thread bolts that will be more resistant to loosening; fine thread
> > bolts
are
> used on auto drive shaft flange applications.
> >
> > There is limited
space
> between the back of the transmission flange and the
> > transmission
but I will
> also investigate using a nylock self locking nuts
> > there. 
There is also
> limited wrenching space between the bolt heads and
> > the
driven flange that may
> present problems finding a suitable bolt.
> > Perhaps
this is why the bolt head
> is 15mm across the flats.
> >
> > I also will had
a look at the motor mounts and
> cutlas bearing as the prime
> > source of the
vibration that loosen the
> bolts.
> >
> > A quick search of this forum found
no similar discussion.
> >
> >
> Comments welcomed.
> >
> > Regards
> >
>
> Ken Geiger
> > Northern Dream #765
> > on
> Georgian Bay
> >
> >
> >
>
>
>
>
> --
> Chris Burti
> Farmville, NC
>
>
>


-- 
Chris
Burti
Farmville, NC