Replacing Shaft seal: Can't remove shaft

Discovered my shaft leaking a while back, I've been holding off on repairs for a while and just let it leak in. Put a toll on the bilge pump and is definitely worsening. My problem comes when I attempt to remove the shaft to slide the shaft seal out: I can't seem to remove the nut holding the shaft to the flexible drive coupler (pictures below). Would the thread on this nut be clockwise? The shaft doesn't turn while I'm (attempting) to loosen it...not sure at all.

Picture 1 is a bit blurry but its the only straight on picture of the nut. The nut is at the bottom of picture 2 (the shaft seal is at the top). Picture 3 shows the flexible drive coupler, which the nut is behind

Any help would be appreciated, much thanks

Sorry I do not have any advice. The one thing I do know is that this can be a very challenging job. Even for the pros. I do know of cases where shafts have to be cut out. I am having my seals on my boat changed at this very moment(professionally). And getting the shaft out of the coupler is the one X factor that even the pros cannot guess at. Mine luckily came right out(they are basically corrosion free). But it doesn't always work out that way.

I gave up on my coupler after seven 8hr. days with dry ice, torches and penetrating oil.

Bought a 7" disc grinder with cut-off wheels ....... 20 minutes .... new coupler.

Where is it leaking on that PSS seal? If bellows is in good shape often crud builds up on SS collar and that can be cleaned to stop a leak.

Ski in NC said:

Where is it leaking on that PSS seal? If bellows is in good shape often crud builds up on SS collar and that can be cleaned to stop a leak.

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This is correct. And you can also slide the "rotor"(that stainless steel thing that rotates on the shaft) forward to further compress the bellows which puts (more)force on the "stator"....the black carbon thingy. I tired all the tricks on mine and they didn't work.

Cant tell from the photo but if the seal deal was installed by the PO , perhaps the stock shaft seal bronze is still in place.

If so I would use the cut off tool to remove all of the "new style" seal which can leak at an incredible rate , and use a modern packing .

The new style seals were to stop the hassle of old style packing that needed to leak a bit to cool the unit
Modern packing does not require that.

Greetings,
Welcome aboard.

Baker said:

This is correct. And you can also slide the "rotor"(that stainless steel thing that rotates on the shaft) forward to further compress the bellows which puts (more)force on the "stator"....the black carbon thingy. I tired all the tricks on mine and they didn't work.

Click to expand...

I've tried compressing the bellow already, to some success. It doesn't hold very well and eventually gives way. The SS itself is in good shape (no crud or rust) but it is well past the recommended maintenance/change date. I already have new ones on hand and don't want them getting wasted just sitting around. Thanks for the suggestions anyhow

For future referent, anytime you adjust those set screws you’re supposed to replace them. They do flatten if used again...hence your issue of the stator “giving way”.

boatpoker said:

I gave up on my coupler after seven 8hr. days with dry ice, torches and penetrating oil.

Bought a 7" disc grinder with cut-off wheels ....... 20 minutes .... new coupler.

Click to expand...

wow...quite the story �� definitely want to keep this as a last-last resort
thanks for sharing anyhow

Poker, how did you cut the coupler off without cutting the transmission flange or shaft? Mine will need it someday soon. Thanks all for the pics.

Is the difficulty removing the set screws in the nut? Or removing the nut once they've been removed? Or something else? How to approach it will likely vary with the particulars.

Also, this must be DSS season. I'm waiting for the maintenance kit for mine to show up. And, you know what? Reading this thread...I'm going to get down there today and start keeping it wet with creeping oil ahead of the big day!

I'd rather take it to the yard, turning the project over to the professional.

You can install a spare carbon and end cap with the bellows forward on the shaft, so when it happens again, cut the old one off, slide the new one down and re-install the new one.

I've seen several boats with spinning spares (taped up) on the shaft.

^^ I'd need to see that done on a PYI. On a Tides lip seal type, that is possible, but I'm not seeing it on a PYI. The carbon has to be between the SS collar and the bellows, to change the carbon or bellows the SS collar had to come off, now it is completely apart anyway.

IF I recall correctly, the carbon rings of my dripless shaft come in halves and screwed together. When I went dripless, I bought 3 carbons and had 2 of them installed as spares. If I correct, it is a matter of removing the defective shaft seal, remove one of the spares reassemble in the proper place. If I am not correct, at lease they are on the safe instead of 'hiding some place on the boat'.

gkesden said:

Is the difficulty removing the set screws in the nut? Or removing the nut once they've been removed? Or something else? How to approach it will likely vary with the particulars.

Also, this must be DSS season. I'm waiting for the maintenance kit for mine to show up. And, you know what? Reading this thread...I'm going to get down there today and start keeping it wet with creeping oil ahead of the big day!

Click to expand...

Removing the nut. I've already removed the set screws (i call them grub screws but same ol) without problem

Hope your maintenance kit arrives soon and definitely do oil it every day haha... I'll have to take note on that once I've replaced it

OldDan1943 said:

I'd rather take it to the yard, turning the project over to the professional.

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Sadly in a time and place like mine, there aren't many qualified professionals, a lot of them are self proclaimed without any resumes to go along with their claims

That's gonna take a big pipe wrench. Leverage is your friend. Hoping a wrench are you using?

stubones99 said:

You can install a spare carbon and end cap with the bellows forward on the shaft, so when it happens again, cut the old one off, slide the new one down and re-install the new one.

I've seen several boats with spinning spares (taped up) on the shaft.

Click to expand...

Wouldn't that cause intense vibrations? If it isn't secured (taped at best as you said) they would most likely be off centred from the shaft and cause vibrations. If you could explain that then it would be something to consider after, I'll definitely take a look into it.

kp cheung said:

Sadly in a time and place like mine, there aren't many qualified professionals, a lot of them are self proclaimed without any resumes to go along with their claims

Click to expand...

I have learned to trust the yard I have used for the last 4 yers.

Greetings,
I would highly recommend a good, proper fitting wrench on the hex nut. Pipe wrench anywhere else because IF you chew up that hex nut with the pipe wrench, you then create a bigger problem.

RT Firefly said:

Greetings,
I would highly recommend a good, proper fitting wrench on the hex nut. Pipe wrench anywhere else because IF you chew up that hex nut with the pipe wrench, you then create a bigger problem.

Click to expand...

I'm currently fabricating a 28 inch wrench handle just for this purpose. Definitely will look out for that problem...

I'm still useing packing ; easy to replace so it drippes a little easy to repack even in the water(if you fast enough and have a good belge pump)

FYI, I had a Carver that used a taper on the end of the shaft and a nut inside the flex joint housing. You had to disassemble the flex coupling, push the shaft to the stern, remove the nut and use a pulley puller to pull it off the shaft.

Looks like the importance of galvanic protection and basic maintenance is highlighted. ��*

"...Removing the nut. I've already removed the set screws (i call them grub screws but same ol) without problem..."

Note that in the "morris" taper style couplers there often are usually two sets of stacked screws with the shorter one deep in the coupler bearing directly upon the facet of the nut. It can be really difficult to be seen as is only about 1/8th inch long. Make certain there isn't second set screw. The stainless collar has two O rings that are against the shaft. once dissembled they can be replaced if leaking. The flexible bellows are the tension between the carbon face seal and the stainless steel disk. If the carbon face is scarred or has debris on it's face it will leak. You set the tension by compressing the bellows by sliding the Stainless steel disk back against the carbon disk toward the stern and locking it's set screws against the shaft.

Did you look down the threads of the grub screw holes? Often, they use TWO grub screws, one acting as a jam screw for the one doing the work... You usually find it after you cut the coupler off the shaft and then say Duh!!!

KP,
If you are making a custom wrench for the hex nut, I would make it similar to a flare nut wrench- this will allow you to catch (4) of the (6) sides of the nut and will handle more torque. Another trick an old mechanic taught me is to use Bees wax. You should be able to find that in your location. Apply heat to the nut with a propane torch or a heat gun, then hold the bees wax against the threads. It will get all the way inside the threads- I have used this after using penetrating oil , heat, etc and was amazed when it came loose. You can also drill a small hole 1/4” in the side of the nut and only go in 1/8 inch. This will allow you to put a drift punch in the hole depression and hit it with a hammer in the direction of loosening. Percussion is your friend when trying to get something unstuck.
Good Luck.

Thanks to all those who took the time to read and reply to my post. I still have not succeeded in loosening the nut but have to set that task aside for now as I have to prioritize issues. The flexible drive coupler is not gripping the shaft correctly and often does not transfer all the power from the engine. This is especially difficult to handle when docking and has already been the cause of a tangle. I'd rather keep the topics separated so I'll be making a new post soon.

Thanks again to all