Removal of tranny coupler from shaft

[Frank Langer]

Hi,
I plan to replace the bellows and O-rings on my dripless shaft seal. I have previously removed the tranny coupler from the transmission to do engine alignment, but it's been 12 years since the tranny coupler was removed from the shaft. It is held in place by two opposing set screws. It looks ok, not rusted, but I'm still concerned I might not be able to remove the coupler from the shaft after I remove it from the transmission. I can't really use tools on the prop shaft for fear of scoring it and thereby damaging the inside O-rings on the stainless flange when I reassemble the PSS shaft seal.
Any advice, tips?
Frank

 

[Loren Beach]

Is this work being done while the boat is afloat, or while it is one the hard?

And, about the coupler -- about a decade ago we changed to a split coupler, with the hope that a future shaft removal would be easier. Someday, we will find out!

 

[Frank Langer]

Thanks, Loren. The boat will be on the hard in the boatyard, but I hope to do all the work myself. Based on the PSS Installation video, it doesn't look too complicated as long as I'm careful and follow instructions. My main concern is removal of the tranny coupler from the prop shaft without using tools like vice grips or hammer which could damage the shaft or the coupler.

 

[HerbertFriedman]

transmission coupler removal

there is the technique whose parts are sold by Moyer for A4 engines. The old way was to use long #8 grade (high strength) bolts to push out the coupler from the shaft using the transmission housing plate but there is always the possibility of bending that plate. So Moyer sold a heavy plate with the same hole pattern. Essentially you remove the bolts holding the shaft to the transmission, slide the shaft with the coupler back few inches, use the #8 long bolts and the new heavy plate to push out the shaft from the coupler without the possibility of damaging the transmission plate. I used that many years ago on my A4 and it should work on any shaft coupler.

 

[supersailor]

Good luck with this one, Frank. I had to cut mine off with a grinder. That salt spray just fused it on the shaft. I had to replace my shaft so it didn't matter. Check your shaft for excessive pitting and wear. It's much easier to chop the shaft than the coupler.

I have seen many boats on the hard with shafts that should have been replaced many moons ago. Almost all of them had bad cutlass bearings.

 

[Rocinante33]

Frank,

I basically did the job the way that Herb described it in post #4. I would add that you should soak the shaft and the coupling with PB Blaster for a long time, BUT do not get any on the transmission seals or rubber parts. Also, choose a socket which is slightly smaller in OD than the prop shaft. Insert it between the end of the prop shaft and the transmission coupling, then use the long bolts and tighten the coupling haves together so as to push the shaft out of the coupling. Don’t be too crazy with the torque on those bolts though because you don’t want to damage the transmission output shaft if the shaft and coupling are truly frozen together! If you alternate tightening the sides, it should come out.

BTW, put a hose clamp around the shaft so as not to accidentally push it out of the Pedro tube.

 

[Frank Langer]

Thanks for these suggestions. Would it be reasonable to fabricate a similar plate out of hardwood, drilling four holes to match the coupler holes, and using a socket between them to push the coupler off? The advantage would be to avoid damaging the transmission, but maybe the wood would simply crack or bend without moving the coupler off the shaft. Although there is no corrosion visible, I have no idea how tight that shaft is within the coupler. Is there any chance it might even just slide off once I remove the set screws?
Thanks for your help with this.
Frank

 

[67rway]

Add heat

Much the same as was said above...

Soak with PB, use long socket that fits inside coupling (but pushes on shaft), and good bolts/nuts. Then heat it up with heat gun (or torch), and slowly tighten each bolt thru it's travel.

Mine took several socket lengths and different bolts before the shaft came free.

I've heard it's a good idea to be very patient when torquing the bolts, or risk galling the shaft/coupling.

Also going with a replacement split coupling, and had the shaft balanced and coupling properly fitted by the prop shop.

 

[HerbertFriedman]

others have said that the technique of pushing the shaft out of the coupler with an appropriate sized socket and long bolts is the way to go. Heat and a careful spaying of a product called Kroil (available only on line and demonstrated to be the best commercially available anti seizing agent) certainly help. And you should use grade 8 long bolts. But the possibility of damaging the transmission plate may be small (if you are very careful) but ouch$$$ if you fail. Any you will only know if you have warped that plate when you try to reassemble the shaft with a new (split) coupler. I am pretty sure Moyer sells that thick plate with the right bolt holes or if not, it is a cheap part to have made if you do not have a drill press. I used that plate to push the shaft out of the coupler on my A4 (72 Tartan 30) and it worked like a charm.

BTW, a study done several years ago showed that a 50/50 mix of acetone and transmission fluid, worked as well as Kroil.

 

[toddster]

Frank, you mention two set screws but just be aware there is probably a shaft key in there as well, so forget "twisting" motions - you need to press it. Hmm... I don't actually recall how I did it, but the socket thing seems likely. I then replaced it with the Moyer split coupler.

Here's the problem I have with that at the moment: the split coupler is a bit bulkier than the original coupler. There is practically no clearance in the E29 engine compartment. The shaft exits through a ca. 1.5" hole, into which the coupler will not fit. Now I need to re-align the engine, but there is not enough clearance to back the coupler off the engine with the shaft in place. It's only about 2-4 mm to the back wall. It would have been a trivial thing to drill that shaft-exit hole larger, when everything was disassembled, but looks like a real PITA that will leave an ugly hack job, to do it with the shaft in place. A failure to think enough steps ahead...

 

[supersailor]

The ability to swear is an excellent skill to have for this job. Patience is absolutely essential. I did put a thin coat of marine grease on the shaft and bolts during reassembly in the hope that the next removal will be easier.

 

[tenders]

It is a real bear to squeeze that coupling off. Having done this three or four times over nearly thirty years of ownership of this boat/A4, my advice is to carefully cut off the old coupling with a Sawzall and replace it with a Moyer split coupling, which is an engineering godsend. My shaft access is particularly awkward due to the V-drive (the only downside I've run across yet with this setup) - but whether or not you take my suggestion, it'll be interesting to find out how you feel about it after you get the job finished.

Lots of discussion on the board here over the years - here's one thread.
https://www.ericsonyachts.org/infoe...15666-E34-PYI-Dripless-Shaft-Seal-Replacement

 

[Alan Gomes]

I'd definitely give this a careful look: https://www.pbase.com/mainecruising/image/75740276

 

[Christian Williams]

Marine How To updated format: https://marinehowto.com/installing-a-pss-shaft-seal/

 

[Frank Langer]

Thanks for all the helpful replies!
Frank