[Public-list] Shaft removal

[Don Campbell]

I have done this several times on White Opal, once in the middle of transitting
the Welland Canal when it really was not my first choice. I still have the spark
plugs indelibly sunk into my chest from that time!
    On the Atomic 4, the stub shaft  on the transmission has one half of a solid
coupler on it with a nut and poor locking collar in  a recess in the coupler.
There are  3 bolts attaching the front half to the back half of the coupler. The
back half of the coupler is attached with a set screw to the prop shaft. By
removing the three bolts parallel to the prop shaft, the coupler will undo. If
you need to pull on it to separte the 2 halves, loosen the packing nuts and pull
squarely on the prop while rotating it. Once it begins to separate, you can use
a cold chisel to continue to separate things if you rotate the shaft and put the
chisel in at several different places as you go.  By removing the set screw, the
coupler will slide off the prop shaft. DON'T LET THE KEYS SLIP INTO THE BILGE!!!
Brian has a good idea if you need to use force to get the coupler off the prop
shaft,  with the spacers,  but they need to be less than the  diameter of  the
prop shaft  and not so hard they ruin the threads on the transmission shaft. The
original keys on White Opal were bronze or brass so non-magnetic and difficult
to exricate from the bilge with a liner in the boat. Remove the prop and the
shaft will slide out to the rear, or if you are careful, and rotate the (2
blade) prop as you turn the rudder out of the way,  you can probably get the
shaft out as is. I don't think you can get a 3 bladed prop out still on the
shaft.
    By flatening the locks on the anti slip ring and  removing the nut on the
end of the stub transmission shaft, the front half of the coupler will slide
off.  Take a good look at both the keyways on those couplers. There is very
little material on them at the inside square corner of the keyway and of that
casting and they are prone to breaking and cracking at that part of the casting.
I had to have new ones made. Overtightening the set screw is a major cause of
casting failure! The result is that the key becomes loose, wears to the point
that it is not square, adds vibration to the shaft, loosens the nut on the
transmission shaft, may even take the threads off that nut or shaft, and then
the only thing that propels the boat is the friction of the forward thrust from
the prop on the off centre rotation of the coupler length. It is not a nice
situation. I made it out of the canal without reverse and hoped for wind to sail
to Toronto. Alas, the wind died so had to motor across calm water in the middle
of the lake! Managed a jerry fix in Toronto and made it back up the canal again
without reverse. That is not recommended either as going up , you are put in the
very front of the lock and have to motor right up to a 10 foot concrete wall.
We lifted the boat, pulled the motor and redid both the transmission shaft and
propshaft. We also made a new coupler. The used couplers I found were for sale
at $50 and were cracked too! If you get a new coupler,  make sure the keyways
are 180 degrees apart when the 3 bolt holes line up. The old ones are aligned at
the same place on both halves so add a possible imbalance to the system if the
keys are not the same specific gravity as the shaft or couplers. It is never
good to start out with a drive train out of balance.

    As for rust busters and wrenches, I think the best hope is to use a flat
wrench and a ratchet with a long handle and hope the connecting bolts shear.
They are not big - 1/4" - so if they undo ok and if not ,  they are not
expensive to replace. Don't drop the wrenches into the bilge either! I turned
the shaft so that the bolts were in the easiest part of the circumference to
work on. You may need to have someone hold it at the prop to keep it from
turning though.
Don

"sousa, stephen (ENG)" wrote:

> Peter,
>
> I agree with Brian, I would also buy some Rust Buster and spray the bolts
> and shaft where it enters the flange. If you have a split flange which bolts
> together around the shaft, that would be much easier to remove. Also when
> reinstalling make sure the 1/4 inch key is tight into the shaft otherwise it
> could move out of the shaft. I had this happen with the Yanmar, a gas engine
> shouldn't vibrate that much.
>
> Stephen
>
> -----Original Message-----
> From: public-list-bounces at alberg30.org
> [mailto:public-list-bounces at alberg30.org] On Behalf Of Brian and Elaine
> Timmins
> Sent: Friday, May 14, 2004 6:26 PM
> To: Alberg 30 Public List -- open to all
> Subject: Re: [Public-list] Shaft removal
>
> If you get really, really lucky, just the square headed "set screw" needs to
> be removed. Probably you will need to remove all the bolts, back the flange
> out a little, put a nut (or some other spacer) in the gap between the shaft
> end and the motor side of the coupling, and use longer bolts to pull the
> flanges together (at the same time as the spacer pushes the shaft off the
> flange). You may need to do this with several different spacers until the
> shaft will clear the end of the flange. WARNING, watch your knuckles. Don't
> let the wrenches slip. Brian
>
> >To remove the shaft is is necessary to undo >all the bolts and seperate
> >the
> flanges or will >removing the square headed bolt alone allow >the shaft to
> come out?
> > Peter Amos
> > Tait Tait #478
> >
>
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