Remove coupling from prop shaft

I have disconnected the coupling between the 1 ½ in prop shaft and the transmission and now want remove the coupling from the shaft. It looks like a steel coupling that is rusted on a Stainless shaft and I don’t know if it has ever been off in the last 30 years. There is an allen screw that I assume is pinned to the shaft. It sits about ¾ in above the coupling and had a locknut on it. Using a torch and PB Blaster I was able to get the nut off. I also heated the allen screw then sprayed PB Blaster on it hoping that would allow the fluid to creep into the threads. I am letting it sit for the week until I can work on it later.

Any other ideas on how to get the screw out without breaking it off? Did I mention that I have very little room to work? Go figure.

Try to use "freeze out" by loc tight. It child the metal shrinking it and allows stuck screws and bolts to come out

To me the original Liquid Wrench works best. In any case heating the area around the screw, wiggling back and forth, and tapping on the screw will usually work after a while. As a last resort, if all else fails, you may have to drill out the screw and re tap maybe even to a larger size if need be.
good luck
Steve W

Blue Heron,

The Loctite product is Freeze and Release. You would have to go through a distributer as it is not a regular retail product.

Rob

$20 at Granger. I'll pick it up tomorrow.

I sit corrected!

Rob

If you're in no rush, do this.

Use a penetrating oil. I like any light stuff that smells like wintergreen, as it has methyl salicylate in it and does a great job on corrosion. Let it soak.

Tap it the offending Allen screw with a bronze or brass rod. A lot of times lightly seems to work better than a few times hard.

Ensure the Allen head screw socket is really, really clean. Use a proper size Allen wrench (3/8 socket and sliding t-handle works best) and apply a reasonable amount of torque in both the cw and ccw direction to work the threads.

Add more penetrating oil.

Repeat this cycle often over a few days. It'll work.

Disclaimer: My advice is based upon years of spinning wrenches in the US Navy, working on various pieces of farm equipment, and advising repair on pulp and parer machinery. I've performed similar exorcisms with starters on VWs, Land Cruisers, many English sports cars, and my old BMW engine that was originally in my NT26. I've never actually done this on an Albin 36 (nor do I want too).

PS: While your waiting, you can read (re-read) the first three or four chapters of Zen and the Art of Motorcycle Maintenance. It won't help loosen the bolt, but might tone down the swearing a bit when your hanging upside down in the engine room.

PPS: Don't use the tapping method on the transmission end as you don't want to Brinell the bearings in the tranny.

PPPS: If you have only little room to work, I personally wouldn't use a torch too much. Well, OK, honestly maybe I would, but I wouldn't advise anyone else too.

Date night , thanks I forgot the actual name. But it works!!!

Heads up.

Freeze and Release is just naptha and mineral spirits propelled by LPG (butane and propane). The refrigerant effect is from the latent heat of evaporation of the LPG. Might set off your propane alarm when you put it in your bilge.

Greetings,
Mr. meridian. If that is the chemical makeup of the F&R and it is being used in a very confined space such as the bilge it may be safest to disconnect any and all ignition sources such as shutting down the boat electrically and providing as much ventilation to the area as possible. Please be VERY, VERY careful.

don't waste your time...solid couplings according to some are not reusable anyhow.

4inch grinder with cutting wheel, cut over top of the key so if you go deep you hit the key and not the shaft.

replace with a split coupling and have the shaft checked, trued and any imperfections where the packing was and may have caused wear or corrosion fixed.

Mine cost around $400 last winter and 1/2 the cost was fixing the corrosion with liquid steel or whatever they called it.

with a split coupling you'll never have to worry about getting it off again.

if you choose not to, be careful as many have ruined their tranny or at least damaged it enought to cost way more than a split coupling replacement.

.A single set screw is note enough to hold a shaft in. Some shaft couplers are like the prop end, the shaft is tapered and in held in the tapered coupler by a nut. The set screw keeps the nut from backing off. Feel up on the engine end of the coupler and see if you can feel a recess with a nut in it. If so once you get the set screw out you will have to find a socket that fits the nut. There may not be enough clearance to get a standard socket on the nut so you may have to grind the wall of a socket down to get it to fit. If this is the case and you cant get the set screw out, just drill it out. All its doing is locking the nut in. Once you get the coupler off its simple enough to drill and tap it one size bigger..Ron aboard Annie.

meridian said:

I have disconnected the coupling between the 1 ½ in prop shaft and the transmission and now want remove the coupling from the shaft. It looks like a steel coupling that is rusted on a Stainless shaft and I don’t know if it has ever been off in the last 30 years. There is an allen screw that I assume is pinned to the shaft. It sits about ¾ in above the coupling and had a locknut on it. Using a torch and PB Blaster I was able to get the nut off. I also heated the allen screw then sprayed PB Blaster on it hoping that would allow the fluid to creep into the threads. I am letting it sit for the week until I can work on it later.

Any other ideas on how to get the screw out without breaking it off? Did I mention that I have very little room to work? Go figure.

Click to expand...

Thank you for all the advice.

I ended up cutting it out after trying the other suggestions. I used a 3 1/2" Zip tool cutoff. A 4" grinder would have been much faster but it wouldn’t fit in the space. It took 3-4 hours working in the confined space.

Now the shaft is out it will need work due to some pits and scaling. I now have to get the stuffing box and cutless bearing case off but that will be another thread.

Nice job Terry. And there is nothing better than having a part you just fought hard to remove ready for a picture for the rest of us to admire!! Please let us know how you end up addressing the problems with your shaft.