Learn About Sailboat Engine Gearbox Reconditioning In The Flange

One small problem we encountered was how tospace we prepare for the long haul of heaving the
get the four coupling bolts back into theirbox (heavy when you are kneeling in a cramped
respective holes once in position. They hadposition and leaning forward) onto the engine bolts
wriggled out after some difficulty when removingand then getting all the nuts and washers on and
the gearbox and we worked on the premise thattightened correctly. My suggestion of going on
what came out must go back in. However, onthrough into the engine, removing the bearings
re-assembly the angle was so acute, there wasand checking them was met with astonished
no way they would line up sufficiently to accessincredulity! - they had been replaced previously
the holes in the gearbox coupling flange from theand were fine, so my brand of humour was
forward engine side.treated with the contempt it deserved!
Well, as predicted, the best laid plans very oftenThe only alternative (after much debate) was to
get interrupted - and so it is with our schedule forbolt them up from the aft side with a spacer
having the gearbox back into Patricks' yacht byunder the bolt head. This was tried on one, but as
this Saturday. Our gearbox expert Barry hasthe lock nuts are half as thick again as the bolt
completed the reconditioning and we have it backhead, we felt the clearance from the gearbox
with us now. However, due to unforeseencasing was insufficient - it was down to 1.5mm. In
circumstances we are unable to fit it thisall probability this clearance was enough, but it
weekend and have put it back to Wednesday thislooked way to fine for our liking and in its original
coming week.position the clearance was around 3mm. What to
Barry, of 'Marine Gearbox Services' is one of thedo?
very few and fast disappearing doyens of marineIn the end it was quite simple - we obtained
gear box maintenance, repair and reconditioning.some shiny new locknuts which Patrick ground
With many years of experience under his beltdown on his workshop grinder, taking off 1.5mm
there is no marine gearbox that he doesn't knowfrom the underside.
inside out (excuse the pun) and never comes upAnother dinghy trip out to the yacht saw us
short. His knowledge on all things gearbox iscrunching down around the engine again and fitting
profound and being very particular in his approachthe new nuts. Voila! they fitted perfectly, and with
you will always be assured of the best, and havethe additional spacer under the bolt head we now
complete confidence in his work.had 3mm. clearance between the nuts outer
He showed and explained to us exactly what wassurface (the bolt end being flush with the lock nut)
causing the problem of the boat slipping out ofand the gearbox casing - looked much better, and
and back into gear from time to time and whatalong with peace of mind, it gave us confidence in
parts were worn and needed replacing. It is nota job well done.
the purpose of this article to supply a fully detailedAll that remained now was to couple to the 'drive
manual of the work that needed to be done,saver' and the shaft coupling and this was a
suffice to say that friction clutch plates (sinteredbreeze. The gear cable strut was then bolted
bronze) and steels were worn, the selector forkback into position and the gear cable attached
was too slack as was the selector ring. All theseensuring it was placed in its correct groove.
parts to be replaced along with the bearings, andThe moment of truth had arrived when it was
all seals and gaskets. Any other parts Barrytime to start the engine and test that the gears
considered needed to be replaced as he workedwould take up and operate correctly. With the
through the job would be.engine on and running Patrick slipped it into the
Believe it or not, the Hurth gearbox does actuallyforward position - after a moments hesitation
contain all those parts. It is difficult to believe thatthere was a satisfactory clunk and she was in
(a) that many bits are required for a simplegear - into neutral and into reverse - same clunk
forward and reverse gearbox and (b) they all fitagain and she was in reverse. Grins all round.
into that limited space. It was a wise decision onEverything was working as it should so the kettle
our part to take it to the expert and not attemptwas put on and a sweeter cup of tea was never
to dismantle it ourselves. We had a veryenjoyed more.
informative time with Barry and on coming awayPatrick has just returned from a few days sail up
we wondered what will happen when all thethe NSW coast and reports that when motoring
Barrys' of this world stop their work - a rarethe gears are working perfectly.
breed indeed. In the meantime however, Barry isLessons: With a little time and patience no job
fully occupied with this work and not planning oncannot be tackled on your own boat.
giving it up any time soon.Never be afraid to consult with the experts - in
Having admired the re-conditioned gearbox withthis case it was Barry of Marine Gearbox
its brand new coat of paint from all angles andServices.
following several false starts (colds, 'flu and strongWhen uncoupling the gearbox make sure you
winds, big chop in a dinghy) Patrick and I findleave the four coupling flange bolts in position in
ourselves back on board and fully prepared tothe flange - this will overcome any problems
re-install the gearbox.when re-fitting.
Hunkering down into position in the cramped