stuck propeller shafts

[captainrob1985]

I am in the process of removing the twin Chrysler 318`s from my trojan sea raider for rebuilds but am having trouble removing the propeller shafts. i unscrewed the Alan key nuts from the units that hold the shafts in place away from the hull and loosened the square nut at the transmission and the nuts and bolts that clamp onto the shaft.

So essentially what else is required to remove the shafts (as i have to do seals for them as well). there are 2 large nuts about 6 inches behind the tranny that are infront of a large hose clamped rubber grommet and then into the thru hull pieces.

if anyone could please shed some light on this i would be very grateful.
thank you for your time
Rob

[jav]

Rob-

I'll see if I can help.

1) The shafts should have a flange inside the hull and it's that flange that attaches the shaft to a mating flange on the transmission using with 4 nuts/bolts around the perimeter. Remove those 4 bolts and you should be able slide the shaft with flange aft - away from the transmission. They might be a little stuck and it may be stiff to slide the shaft but it should move with some pursuation and leverage.

2) The set screw or square headed bolts usually secure that flange to shaft itslef with a key. Seperating those flanges from the shaft can be extremely difficult and may require some special tools and heat as they tend to be very tight fits when new and years of corrosion just makes things worse. Unless you want to completely remove the shaft from the boat- you shouldn't need to seperate these components.

3) The large nut about 6" inches behind that flange- with the rubber hose behind it is the "shaft log". There is a seal- or more accurately- series of seals in there but these can be changed without removing the shaft. Look up "shaft packing installation" and that should help.

Feel free to ask if this doesn't make sense.

[captainrob1985]

I certainly appreciate the help, Thank you for a prompt reply. The problem is both propellar shafts are bent and do not spin true. I don`t see an alternative but to remove the shafts and either replace them with new ones or take them to a shop and have them straightened.

the dark history here is before i came into possesion of this boat kids broke into it and ended up sinking it in a foot and a half of water (resting on the prop shafts). so i am making a huge effort here to bring her back to life as she is a goregous boat, so anyone who may have extra propeller shafts or propellers please let me know and i will buy them
Rob

[jav]

OK- than that means you'll need to remove the shafts. Depending on if how bad they are bent and if the shafts are of a good material in good shape, straightneing may be an option. BUT- if they are severly bent, or scored where the shaft seal rides or pitted or just plain stainless shafts- you might want to just cut them off behind the flange and bring the flange and shaft stub to someone with a hydraulic press to seperate them.

If you want to seperate the intact shaft from the flange- here's how I'd do it. BTW I'm presuming your setup looks something like this:


If so- seperate the shaft flange (black on right of pic) from the transmission flange (yellow- further right in pic) as described in my first post (4 silver hex bolts in picture). Slide the shaft aft taking care not to slam the prop into the rudder (if they are still on). Make sure all the screws that secure the flange to the shaft are out (black square head safety wired bolts in picture)- not loose- but completely out. Now comes the hard part- that flange will likley be absolutely frozen onto the shaft. What I usually do is I get an old matching flange (if you can't get one- you'll have to make something up) and get some longer fully threaded high grade bolts like the ones that attached the flange to the tranny. I setup the shaft flange and the old flange (or made up plate) so the 4 bolts go though both but so they are seperated by about 2". Now- I cut a 1.5-2" long piece of scrap steel rod a little smaller in diameter than shaft and stand it up between the 2 flanges making sure that rod piece is hitting the shaft end and not the flange and snug up the bolts. This makes a sort of press to push the shaft out of the flange. You tighten the bolts in 1/4 turn increments all around until the shaft presses out.


If it won't budge (which happens)- a little heat can help.


CAUTION- THIS NEXT PART CAN BE DANGEROUS SO BEFORE IGNITING A TORCH IN THE ENGINE ROOM - MAKE SURE YOU TAKE APPROPRIATE PRECAUTIONS AND HAVE NO COMBUSTIBLES OR FUMES IN THE AREA. HAVE A FIRE EXTINGUISHER HANDY.


I pull the whole shaft forward a little bit away from the shaft log and wrap a wet rag around the shaft (behind the flange between the flange and the shaft log) I also lay a wet towel on the hull under the flange where I intend to use the torch. - Make sure the bolts compressing the flanges are as tight as I can get them and I CAREFULLY use a propane or mapp gas torch to heat and expand the flange where it grips the shaft. That usually does it - if not some careful hammer taps can help as well. Once the flange starts to move - don't pull it completely off while it still hot or it will be hard to handle- get it 80-90% off then let it cool before popping it all the way off.

[captainrob1985]

That is Exactly what my setup looks like. I will keep you posted on how it progresses.
Rob

[gjrylands]

That was a great explaination. I would add trying to soak the flange with penitrating oil. With the cap bolts out you will be able to put some oil down the screw holes And let it soak. The only problem is if you need to heat the flange you will need to wipe as much of the oil off before you apply the heat so you don't start a fire.

[chucka]

Since you said you are removing the engines for rebuild, there is an alternate to Jav's approach. When I had the engine out of my last boat, I was able to remove the prop from the shaft and slide the entire shaft with flange intact forward through the stuffing box and remove it from inside the boat. With this approach, you should completely unscrew both nuts from the stuffing box, and leave them loose on the shaft before attempting to slide the shaft forward. The issue you may have with this approach, since your shafts are bent, you may not be able to pull them through the stuffing box. If they are slightly bowed, they may be able to slide through, but if they are kinked, forget it.

I'm still boatless, but looking.

Good Luck,
Chuck