[C320-list] Transmission Drive Flange Bolts Fall Out

[Ken Geiger]

I have since found, in a Yanmar Transmission manual (not the one for the 3Gm) and else where, that the "7" on the bolt head means "JIS Strength Classification 7T" and should be torqued to 36 ft-Lb.  I will check how I did with my small wrenches using a torque wrench.

Ken
Northern Dream #765

 

 

 

---- Original Message ----
From: Chris Burti <clburti at gmail.com>
To: 320 <C320-List at catalina320.com>
Sent: Sat, Aug 15, 2015 8:07 am
Subject: Re: [C320-list] Transmission Drive Flange Bolts Fall Out


I'm sure that those were what I was recalling rather than the
flange
bolts..thanks!

On Fri, Aug 14, 2015 at 2:08 PM, Rick Sulewski
<rsulewski at bex.net> wrote:

> Chris,
> On my boat with a Westerbeke engine,
the only bolts in the drive system
> that are safety wired are the 2 bolts that
help secure the dimpled prop
> shaft to the shaft coupler (flange). The four
bolts that secure the prop
> shaft coupler (flange) to the motor drive coupler
are secured with lock
> washers. Absent the lock washers that are fully
collapsed/very tightly
> secured, one could anticipate loosened bolts over time
without lock
> washers, given the normal vibrations from a 3 cylinder diesel. 
As with
> most high vibration machinery, periodic inspections are
recommended...and
> never experienced such a problem after 1,350 hours.
> Rick
95' C320 Hull #277
>
> -----Original Message-----
> From: C320-list
[mailto:c320-list-bounces at lists.catalina320.com] On
> Behalf Of Chris Burti
>
Sent: Friday, August 14, 2015 12:59 PM
> To: 320
> 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
>
>


-- 
Chris Burti
Farmville, NC