[C320-list] Transmission Drive Flange Bolts Fall Out

[Rick Sulewski]

Ken,
Suggest all metal nuts & fine threaded bolts with lock washers on the nut side of the flange. That is what I have on my Westerbeke model and have not had any issues with loose flange bolts after 1,350 hours. 
Rick

-----Original Message-----
From: C320-list [mailto:c320-list-bounces at lists.catalina320.com] On Behalf Of kendgb
Sent: Thursday, August 20, 2015 12:42 PM
To: C320-List at Catalina320.com
Subject: Re: [C320-list] Transmission Drive Flange Bolts Fall Out

The transmission on #765 is a Kanzaki KM2P.  

The flange bolt heads are not drilled for Wires and I do not see a point to that as the nuts are not held even with a lock washer an so could come lose even with the bolt heads wired.  

My neighbour's Hunter 35.5 had nylock nuts, a better idea than what is on this boat. Imho

I checked my torques today and found that the field fix with wrenches met or exceeded the specified 36 ft-lb.  

I will continue to search for some fine thread hi strengh metric bolts and nylock nuts as time permits in order effect a better fix.

Ken


Sent from Samsung Mobile

-------- Original message --------
From: Chris Burti <clburti at gmail.com>
Date:08/15/2015  8:07 AM  (GMT-05:00)
To: 320 <C320-List at catalina320.com>
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