So I’m in a predicament and in need of advice from this knowledgable group.
I broke off one of the two screws that secures the prop shaft coupler to the prop shaft. We have tried everything to remove it including attempts by mechanics. It is permanently “welded” by rust to the coupler. We have tried drilling it out with cobol drill bits and after many hours we have only made a dent (literally) on it. Don’t ask me how I got here. It is very embarrassing however it is documented in prior emails and forum postings for your laughing pleasure. Bottom line the bolt remnant is there to stay so what to do next. I have come up with the following alternatives in order of least difficult to most difficult and involved:
1. The bolt remnant, which is over an inch long, won’t and never budged therefore it should still be secure to the prop shaft and therefor still doing the job it was intended for. Attempt to remove the prop shaft from the coupler with bolts, nuts and a socket wrench and if that is not successful secure the second bolt, not a problem since it came out without issues. Monitor it regularly but rely on the fact that the bolt is practically welded in place and continues to secure the shaft as it was always intended to. If in the future I want to change the shaft I can do alternative #4 below.
2. Drill another hole on the coupler close to the broken one and tap it so that another bolt can be put in. In effect having three screws holding the shaft to the coupler.
3. Cut the coupler lengthwise down to the shaft, remove it and replace it with a new one. There is a chance of damage to the shaft.
4. Cut the shaft so that the coupler can be removed, and replace the shaft and coupler.
I am leaning for number 1 unless someone can convince me it is too risky or unreliable.
Comments pleeeeeeze
Enrique
Talisman MK2 36 1998 Hull #1673
Tall Rig, Wing Keel, Universal M35B engine
On the Hard in South Glastonbury, CT
Enrique
Talisman
1998 36 MK2 Hull #1673
Tall Rig Wing Keel
M35BC engine
Old Saybrook, CT Summer
South Glastonbury, CT Winter
I vote for #1. Put the other bolt back in using Red Loctite and call it a day. When it ever becomes necessary to remove the coupling, then your other two options are viable. At that point, the least amount of labor would be to cut the shaft and then replace the shaft + coupling.
Nick Caballero
Retired C36/375IA Mk II Technical Editor
Talisman - you did not mention why you were trying to remove the coupler. I tried the very same move and both of the bolts sheered off. I was trying to replace the stuffing box. I ended up having to cut the bronze shaft and replace it with stainless steel shaft and a trued coupling. When I removed it, I discovered the wear on shaft at the cutlass bearing. So it needed to be replaced.
I made this device to try to push the shaft out - but it would not move. The wood dowel represents the shaft.
Sail La Vie 1999 Catalina 36 MKII, M35B-17031, Coyote Point, San Mateo, CA
About Sail La Vie
If you have no need to remove the shaft #1
If you need to remove the shaft #4...
P.S. In a properly made shaft the set screws are set into "spotted" dimples in the shaft.. No amount of pressing with bolts will get it off....
-Maine Sail
https://www.marinehowto.com/
Thank you all. This has been very helpful
Enrique
Talisman
1998 36 MK2 Hull #1673
Tall Rig Wing Keel
M35BC engine
Old Saybrook, CT Summer
South Glastonbury, CT Winter
Enrique
I replied on the List but will do so again here as it may be useful for others.
Your problem is not as bad as it seems. If you need to remove the coupler simply cut it off lengthwise carefully with an angle grinder so as not to damage the shaft and replace it with a split coupler from Buck Algonquin. Simple, quick and relatively cheap. I've done it on my boat.
Peter Taylor Melbourne Australia. Altair #2227 2005 C36 Mk11
Ditto to what Peter said.
Here's a video clip that shows how someone split the coupler to remove it:
www.youtube.com/watch?v=qM45997JCRI
I actually did succeed in veeerrrry sloooowly pressing the old coupling off a few months back using the long bolts/captured socket method, and wasted quite a few hours of my life I'll never get back in so doing.
Why wasted?
Because in the end I replaced the coupling anyway since
a) reusing the old one is not likely to get a good fit -- see www.youtube.com/watch?v=onmkD4PnRlk and
b) a new split Buck Algonquin coupling, machined at the prop shop to fit properly and true, will make for a much easier reinstall (and future removals).
Matthew Chachère
s/v ¡Que Chévere!
(Formerly 1985 C36 MKI #466 tall rig fin keel M25)
2006 Catalina Morgan 440 #30.
Homeported in eastern Long Island, NY
I'm thinking that most folks that have used the slit method have been able to remove the set screws before starting the slit. With a stuck screw and with a slit over the key you still might not get the shaft to slip out because the screw is still in the dimple, acting as a dowel. If you do go with the slit method and you have a stuck set screw, it might make more sense to cut the slit along the stuck set screw instead of along the key. Before completing the cut, since you now have a slit in the screw and some grinding heat, using a flat screwdriver try getting the screw to turn while the area is still hot. If you get a bit of turn, flush the slit with light oil before further unscrewing. Naturally you've taken all of the necessary precautions of the combination of sparks, heat, and flammable objects in the area.....
If the screw does not come out after completing the slit, then you're next move would be try collapsing the slides of the screw into the slit, cutting more slits, or just cut the shaft and be done with it. That delicate balance between the check book and the Chiropractor always comes into play....
Nick Caballero
Retired C36/375IA Mk II Technical Editor
I've decided for option #1. Leaving the broken screw in. The shaft is not going anywhere. If and whenever I have to replace the shaft or anything else I will either cut the coupler or the shaft.
I'm surprised there are no gaskets physical or chemical between the transmission and bell housing. I guess there is no fluid there to leak out or friction to cause wear so it is metal to metal contact.
Enrique
Talisman
1998 36 MK2 Hull #1673
Tall Rig Wing Keel
M35BC engine
Old Saybrook, CT Summer
South Glastonbury, CT Winter