Help Needed To Remove Prop Shaft

[fallingeggs]

Hello! I am attempting to remove my prop shaft so that I can replace my worn out looking stuffing box and cutless (stave or cutlass) bearings.



I removed the two set screws from the coupling, but nothing moved. So I removed the four bolts holding the coupling to the transmission and now the shaft moves back forth freely, but for only an inch.

It seems my shaft is very well stuck in the coupling. I took some PB Blaster, a rubber mallet and some light taps to it, but no movement. I can see that the set screw holes haven't budged at all.

What do folks think about heating it up? I have a sizable butane torch that should do the job. Then retap with the rubber mallet or pull from the prop.

Anyone have other options?


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[Bluemansailor]

Sometimes it just won't move and you have to cut it out. Had to do that on my last boat.
See mainesail's article.
A New Prop Shaft Photo Gallery by Compass Marine How To at pbase.com

before that try either making or buying a coupler puller..
Coupler Puller Photo Gallery by bartenderdave at pbase.com

good luck.

[fallingeggs]

Originally Posted by Bluemansailor

Sometimes it just won't move and you have to cut it out. Had to do that on my last boat.
See mainesail's article.
A New Prop Shaft Photo Gallery by Compass Marine How To at pbase.com

before that try either making or buying a coupler puller..
Coupler Puller Photo Gallery by bartenderdave at pbase.com

good luck.

Thanks for the links. I really hope it doesn't come to cutting it out.

Will try the puller, but I don't have much room. What if I used the transmission bracket as the backing plate? Get four bolts longer than the originals and place a short bolt where the shaft is. In concept it seems the same. Just depends on how strong the transmission is.


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[sailorboy1]

Originally Posted by fallingeggs

Thanks for the links. I really hope it doesn't come to cutting it out.

Will try the puller, but I don't have much room. What if I used the transmission bracket as the backing plate? Get four bolts longer than the originals and place a short bolt where the shaft is. In concept it seems the same. Just depends on how strong the transmission is.


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Nothing wrong with heat as long as you don't catch on fire.

Cutting it off may not be a bad idea if it is rusty. If it is you really should get a new coupling because once you take the old one off the fit will be ruined.

Be VERY careful of using the transmission coupling and bolts/spacers to pull off the shaft coupling. It will ruin your day if you break the coupling on the transmission.

[Bluemansailor]

I wouldn't use the transmission couple too many things could go wrong. May have to bit the bullet and cut and replace.

[gonesail]

you could cut the stuffing box hose away and maybe gain enough room to go with the coupler puller?

[John Boor]

Cut away the old flex hose to give more room Fabricate a thick metal plate with holes that align with hole pattern of flange get long fine thread nuts and bolts place socket that is smaller that shaft dia and place between metal plate and end of shaft bolt all together and tighten slowly and evenly. this should work use pb blaster or other fluid to penitrate shaft and flange.
john

[Zach]

You can set a socket that fits just inside the shaft's diameter between the coupling on the transmission and the shaft flange as a first step. It'll take longer bolts, but you can do it with an inch of play.

Don't crank it down and try to break it loose, but put 20 foot lbs or so on each of the bolts. Just use a stubby 3/8's ratchet, or box wrench rather than breaker bars... Don't hammer on the transmission side of the coupling with the bolts attached, unless you want to install a new rear transmission bearing.

Hose everything down with penetrating oil, and come back the next day.

Take a torch and heat the shaft coupling up until the penetrating oil burns off, and spit sizzles off the shaft beside the coupling. Think 10 minutes or so of heating. It helps if you can rotate the shaft over, and evenly heat the coupling.

Let it cool down.

Spray it with penetrating oil again after it has cooled down enough that you won't make it in the paper for self immolation...

Try to put a 1/4 turn on your coupling bolts. If they are just as tight after a 1/4 turn... stop. Loosen them completely and verify the socket has not slipped and is contacting the face of the coupling, instead of the shaft.

Tighten back down, and bring out the torch again.

I use map gas, on a torch with a flexible hose.

If you have clearance for a gear puller, sometimes you can cut the shaft hose out of the way to slide the shaft aft. Sometimes in a pinch, a harmonic balancer puller can be put into service... Though you may have to whack the threaded end down short enough to fit the space you have.

Heat under tension works better than a lot of tension alone...

Cheers,

Zach

[Tingum]

I second the Mapp gas, propane and butane do not get hot enough.

[SVJennie]

Zach's directions sound good. Perhaps there may be a couple of other options. Here is one.

1. Assuming you have access to the prop end of the shaft:
a. remove prop
b. Remove flex hose
c. cut piece of pipe that will closely match shaft log diameter and is long enough to allow enough space to safely cinch down on prop nut.
d. Using large metal washers place them between prop nut and and piece of pipe. For safety's sake (not to damage shaft log), it would also be well to place a washer twixt pipe and shaft log.
e. carefully cinch down on prop nut to take up slack and to put pressure on shaft coupling. Heat coupling if necessary.

Now, after all that, I had a similar situation with a coupling on my rudder stock, and wished had cut the coupling to begin with, which I did in the end. However, the coupling I am referring to was not as heavy as the shaft coupling, so it was easier. But then again, you only need to cut the coupling where it contacts the prop shaft, and maybe just a little bit farther.

Good Luck!

[SVJennie]

Second option:

If after removing flex hose, there will be enough clearance twixt couplings to slide bell housing with transmission attached, free of splined shaft, you would probably have enough room to use a gear puller to remove shaft coupling. However, when trying to remove bell housing, you may run into other problems like being unable to remove rusted bolts, or worse, having them break of and then having to drill and retap the holes.

Again, GOOD LUCK!
Remove

[Xlantic]

A method similar to the one described by Zach, from This Old Boat by John Casey:

Remove the bolts that hold the coupling together using a six-point box-end wrench or a six-point socket to be sure the wrench will not slip. Back off the compression nut on the stuffing box, then slide the shaft back and note whether the end of the shaft is flush with the face of the flange or recessed. Now find four or five nuts and short bolts of different lengths to use as spacers. Tape the shortest spacer against the end of the shaft and slide the shaft forward, sandwiching the spacer in the middle of the coupling. Insert the coupling bolts and tighten evenly. As the coupling bolts pull the shaft flange forward, the spacer prevents the shaft from coming with it, thus pressing the shaft out of the flange. If the shaft doesn’t budge, don’t crank down on the coupling bolts until you warp or break the flange. Try expanding the flange with heat from a propane torch. Do not heat the half of the coupling that’s attached to the engine or you will destroy the rubber oil seal around the driveshaft. Replace the initial spacer with progressively longer ones to press the shaft all the way out. Be sure to spread a cloth under the shaft to prevent the shaft key or the spacer from dropping into the bilge. From outside, slide the free shaft completely out of the boat.

[JeffBurright]

This wouldn't help with your stuffing box, but you can replace the cutless bearing without removing your prop shaft. I did it while the boat was in the water, and you can see the tool I made for the job here: The hard way: changing a cutless bearing underwater — Take to the sea | Sailing blog | The sailing and cruising (mis) adventures of SV Serenity

For removing the shaft from the shaft coupling, I second the suggestions to put a socket between the two coupling faces and tighten longer bolts round robin style. It's too bad there's not a way to replace a stuffing box without removing that coupling. Somebody should invent something!

Brain flash! We need one of these, but stuffing-box sized with rubber seals on the clamshell and fold-over lockable snap locks on either side: http://shoals.com/products/mc3-locking-clamshells/

[Cadence]

Originally Posted by fallingeggs

Hello! I am attempting to remove my prop shaft so that I can replace my worn out looking stuffing box and cutless (stave or cutlass) bearings.

Attachment 98787

I removed the two set screws from the coupling, but nothing moved. So I removed the four bolts holding the coupling to the transmission and now the shaft moves back forth freely, but for only an inch.

It seems my shaft is very well stuck in the coupling. I took some PB Blaster, a rubber mallet and some light taps to it, but no movement. I can see that the set screw holes haven't budged at all.

What do folks think about heating it up? I have a sizable butane torch that should do the job. Then retap with the rubber mallet or pull from the prop.

Anyone have other options?


Sent from my iPhone using Cruisers Sailing Forum

The rubber mallet is not giving you any shocking. I might put a little heat on the hub of the flange and us a drift pin taping around the hub, with a hammer, not on the flange. Don't try to cook it, just expand it without expanding the shaft.

The idea of using a plate to make a puller sounds good. I don't think using the flange on the transmission is. If you get a little heavy handed with the wrench tightening and break the flange on the transmission, you have another problem.

[svJasmine]

use longer bolts on the coupler. get a small socket in there to press the shaft out. Tighten all the bolts. This should press the shaft out of the coupler.

repeat with something larger until it slides out.

I have done this on at least 5 boats and made it work.

good luck.

try to keep the cussing down, we can hear it thru the internet ;-)