Coupling removal

Tally Ho · Oct 26, 2019

The coupling is a press fit on to the propeller shaft, and if it is old and rusty, it will be difficult to get off.

Many people just cut the shaft in half and remove it that way. if you are planning on replacing the shaft, this is the easiest/fastest way to do it.

If you want to keep your shaft, then you probably will need to press the shaft out of the coupling. I did this on my 30 year old O’Day 322.

I used a round plate, with holes in it, to bolt to the coupling, put a socket in the end of the coupling, to press against the shaft, and then tightened the bolts...pulling the coupling and my plate together, pushing the shaft out of the coupling....

Here is a video....

My shaft was bad, so I replaced it...

And finally replaced the stuffing box hose (not the actual box that was OK) and put it all back together...

I assume your boat is out of the water...don’t try this in the water!

Good luck with your project...like most things with boats, this will probably be more involved than you orit’s ally thought.

Greg

jssailem · Oct 26, 2019

Elizabeth you are looking at two flat plates, they were "aligned", and bolted together. You likely have some corrosion that has in effect cold welded the metal making removable a bit of an issue. Note that they were aligned before they were bolted. Separating them will modify this and you will either want to mark the current fittings before separating them or anticipate all new reinstall and alignment.

You are, I suspect, out of the water.

Are you replacing the shaft? You mention "Stuffing Box" You do not have to remove the shaft to replace the flax in the stuffing box. Are you installing a no (less) drip stuffing box?

First thing that springs to my mind is Heat and cold to separate the face plates with out doing damage.

There are others who may have a better idea.

Tally Ho · Oct 26, 2019

I just reread your post and your pictures...sorry. I see you are asking about your Tranny flange and coupling flange. Those should not be too hard to separate.

I think a few light taps with a hammer on the outside edges of the flanges might loosen them up. Don’t pound on it as you can damage the transmission...but a few love taps might do the trick. Otherwise, you can spray them with some penetrating oil, let them sit for a day or 2, and try a love tap again.

I don’t believe these 2 flanges are pressed together. Probably just bolted tight for a long time.

Greg

Hayden Watson · Oct 26, 2019

Also the friction in the stuffing box is keeping the shaft from sliding out so that the flanges separate. Try turning the shaft while pulling back to help overcome the friction. once you get a small gap you can start with a screw driver to help lever the flanges apart and move to larger pry bars. Is the plan to remove the shaft from the boat?

gettinthere · Oct 26, 2019

be careful on whacking the flange on the trans, you can damage the trans.
Apply PB blaster and a few LIGHT taps to get it to seep in. Then repeat. Then repeat. Then repeat. Might take 5 or 10 tries to get it to let go. Also, do NOT let the PB blaster get onto any seals at the back of the trans.

You will likely face an even more difficult process when you try to remove the coupler from the shaft. I tried and tried and tried. Waste of time. I drilled a series of holes into the thinner metal where the key is in the keyway and eventually it cracked which opened it just enough to remove it.
When you buy a new flange for the shaft, you will need to have the flange custom fit to the shaft. They are always made just very slightly small to make sure it will fit. A machine shop will enlarge it to a proper press fit. That fit is TIGHT for a reason, so it has zero play.

Have fun!

dLj · Oct 26, 2019

Elizabeth said:
Hello,

I am a new lady sailor. I am trying to change the staffing box in my hunter 40 legend but after taking all things apart I am having problems detaching the transmission coupling from the shaft coupling. Any help is greatly appreciate it. I have removed all screws but I can not separate them

please help!

It's not 100% clear to me what your final goal is here. You say "changing the stuffing box" - does this mean you are replacing the metal parts and the hose of the current stuffing box? That means you have to pull the shaft. Tally Hoe's explanation will allow you to pull the shaft out of the boat from the outside. Then you can replace all the stuffing box parts. The other way of pulling a shaft requires removing the engine, dropping the prop and pulling the shaft in.

If you are only going to re-stuff the stuffing box to make it so it doesn't leak anymore, you don't need to take that flange apart. You can just put the bolts back in and work on the stuffing box flax replacement (or more modern Teflon based material).

If you can explain better why you need to separate the shaft to tranny flange then perhaps we can give you suggestions on how to achieve your end goal.

To pull that flange apart, I have used two metal wedges and a large C clamp, placing the two metal wedges at 180 degrees from each other and using the C clamp to press them into the gap between the flanges. It's rather non-violent and I've always had pretty good success doing it that way. I do have some pretty big C clamps though, so if you had to go buy one then you can just use the two wedges, take a sledge hammer and rest it on one wedge, then tap the other wedge with a light hammer. Rotate sides and repeat. This however is usually done much easier with two people.

dj

P.S. I make my wedges, that might be a hard part for you if you don't have metal working capabilities.

Charlie Jones s/v Tehani · Oct 26, 2019

Getting the shaft out of the flange is not a huge deal. Takes some longer bolts and a socket just smaller than the shaft Slide the shat and that flange aft afr enougbh to insert the socket against the shaft. Put the longer bolts in and tighten. This will gradually force the shaft from the coupler. Bolts of course must be long enough to bridge the resulting gap

Learned this trick from Harl De Villiers, the first deaf sailior to singleehand around the world

Hayden Watson · Oct 26, 2019

We are still curious as to what your end goal is. Being new to all of this you might be doing something that could be more easily accomplished in another way. pretty much anything you are wanting or needing to do has already been done by someone on this site and we are usually more than happy to walk a new boater past some of the holes we have fallen into. :beer:

Tally Ho · Oct 26, 2019

Hayden Watson said:
We are still curious as to what your end goal is. Being new to all of this you might be doing something that could be more easily accomplished in another way. pretty much anything you are wanting or needing to do has already been done by someone on this site and we are usually more than happy to walk a new boater past some of the holes we have fallen into.

Amen....

Greg

Charlie Jones s/v Tehani · Oct 26, 2019

amen on the assisting new folks. Part of being a sailor. Just spent an hour or so teaching a new to sailing friend some knots. I've only been tying them since I was 8- only 70 years ago

Richard19068 · Oct 26, 2019

Hayden Watson said:
We are still curious as to what your end goal is. Being new to all of this you might be doing something that could be more easily accomplished in another way. pretty much anything you are wanting or needing to do has already been done by someone on this site and we are usually more than happy to walk a new boater past some of the holes we have fallen into.

From what she said it sounds pretty clear that she is changing out her stuffing box and not just repacking.

Can't imagine anyone thinking they had to separate the coupling to repack.

RoyS · Oct 27, 2019

You can by a flange puller tool from Buck Algonquin if you have room to use it behind your transmission.

dLj · Oct 27, 2019

RoyS said:
You can by a flange puller tool from Buck Algonquin if you have room to use it behind your transmission.

View attachment 171350

That looks like a good one. You can also go to AutoZone and buy one, use it, then take it back and get your money back. This is not a sleezy thing to do - AutoZone is actually promoting it. That way you can get to use pricey tools that you may need only once in a great while instead of having to buy them. It ends up costing you nothing. My brother and I did this to pull his wheel when we changed his autopilot. We couldn't get his wheel off and finally decided we had to go buy a wheel puller. Went to the local AutoZone to buy one and the guy there told us about this "buy and return" policy they had established. I told him that the wheel puller was not going to come back in pristine condition and he told me it was no problem... So that's what we did and got to use a wheel puller for a day essentially for free. We just had to drive back and forth from the boat to the store. But as RoyS said, you have to have the room to use it.

dj

smokey73 · Oct 27, 2019

dLj said:
That looks like a good one. You can also go to AutoZone and buy one, use it, then take it back and get your money back. This is not a sleezy thing to do - AutoZone is actually promoting it.

dj

dj, just a point of clarification. Its promoted as a "loaner tool" program. They do the same thing at Advance Auto and probably at other auto stores. They have certain tools they do this with, but not ALL tools. Its a great program and a real money saver for the user and a great promotion for the stores. They figure you'll get the parts there too when you come in for the loaner tools (or code reading too) so its a win-win. They charge you the new price for the tool when you pick it up (new or used when you get it) and if you keep it they keep your money. If you return it you get all your money back. If you get a previously used tool make sure all the parts are there when you pick it up and bring it back. I don't want readers here to assume you can buy any tool and then take it back after you've used it - that would be sleazy.

dLj · Oct 27, 2019

Ah, thanks for the clarification. My brother and I walked into the store to buy the wheel puller and the guy told us to just bring it back, no questions asked. He probably gave us more info at the time, but as it's a few years ago those details are gone from my brain. I thought it was fabulous. We really only needed the wheel puller for one day. It's a great service! I'll go back for parts, for sure!

dj

chuckwayne · Dec 29, 2021

It's great that you got the flanges apart! just a caution... some Hunter shafts, like our 356, have a threaded end on the shaft and a NUT Inside the flange. After separating the flanges, if you need to remove the flange you may have to move the shaft aft until you can get inside the flange with a large socket and ratchet.

MitchM · Jan 1, 2022

On my nauticat 321 i had to replacea bent p shaft. The coupler was a centa. The centa website had complete directionson how to remove the coupler . The trick wasto know the coupler had 3 visible bolts and three jakbolts hidden underpressed on covers. Centa even had a us phone number answered by humans. They were great to deal with. Other major coupler manufacturers may have similarhelp available…

justsomeguy · Jan 1, 2022

dLj said:
It's a great service! I'll go back for parts, for sure!

That's what they're counting on.
Autozone has been on a PR blitz recently. A good thing!

Coupling removal

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