Will the driven coupling really fit?

PSR

PSR

.
Sep 17, 2013
117
Catalina 27 4743 MB Yacht Harbor, Richmond CA
What a day! I finally looked at the shaft coupling after deciding to replace the shaft (very pitted). The coupling looks like something trying to crawl back into a Devonian swamp - iow, it is UGLY. the shaft has to be cut and pulled, then the nuts on the coupling bolts will have to be cut & some providence will have to intervene to split the coupling after that. Assuming this all works out and the transmission side is ok, and when I have a new shaft and coupling in the shop, it all needs to fit together. This is what Catalina Direct writes about the new driven coupling:

"This is the original equipment coupler for the forward end of the prop shaft on your Universal Diesel. A mating piece is machined onto the output shaft of the transmission. Four bolts with nuts, washers, and 2 set screws (drilled for safety wire) fasten the engine and shaft ends of the coupler together."

With great respect for CD, still, can anyone reassure me that the new coupling really will fit after the rust has cleared? "Mating" suggests a tight fit in should happen...but who knows. I will see the driven plate before ordering, but tonight I'm concerned about what will be necessary if that driven plate does not promise to mate....
 
Meriachee

Meriachee

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Aug 1, 2011
3,972
Catalina 270 255 Wabamun. Welcome to the marina
Ordered shaft and coupling, "faced" from CD last year. Fit like a dream.
I'm 800 miles from any kind of boat yard (besides my garage) and parts really need to go together the first time.
That said, Marek (who I'm sure will chime in) didn't get the right coupler for his the first time, but CD was great at getting things straightened out.

Cheers
Gary
 

Attachments

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TLW

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Jan 15, 2013
271
Oday 31 Whitehall, MI
The "mating" is a matter of both couplings being absolutely parallel. Ordering the shaft "faced" makes certain the new coupling is perfectly perpendicular to the new shaft - it will be - that's what you are paying for. The coupling on the transmission will be adjustable by adjusting the motor mounts - this is the alignment that is so important. You should have NO PROBLEMS installing the new faced shaft/coupling and aligning it with your existing transmission coupling even after removing the rust.
 
PSR

PSR

.
Sep 17, 2013
117
Catalina 27 4743 MB Yacht Harbor, Richmond CA
Thanks for the encouragement Gary & TLW. I wish my transmission/coupling/etc looked as clean as yours, Gary. It doesn't. This is how it looked to me when I first checked on disconnecting the coupling:

.

The mechanic I am working with looked at it and said it was about the worst he had seen in 20 years, although he allowed as he had worked mostly on new, or at least newer, boats. In Gary's photo, the coupling parts look just like the pictures on CatalinaDirect.com and like the diagram in my handbook for the boat. The mechanic cleaned a lot of the rust off after this picture, and the parts are more distinct. But it does not look like the coupling shown in the manual, or in the CD photos. It looks like this:



...but it is very rusty. Does anyone recognize this coupling? I probably need to find something different to connect to this transmission if all can be cleaned up enough to use.
 
Meriachee

Meriachee

.
Aug 1, 2011
3,972
Catalina 270 255 Wabamun. Welcome to the marina
Did you share these pictures with CD? It costs nothing to ask.

There's also another thread (look for PSS) on this site that references "split couplings" - yet another source of data.

There's also a Yahoo group for the 27, if you are not aware, and somebody has done this job, very likely with your specific installation. Just ask.

BTW, mine was WAY greener than yours. Once I get a coat of Brightside in there, the white will be white. It matters. :)

PS
I'd strongly urge you to get a new shaft, coupling, do the cutlass bearing, and either a new stuffing box or PSS. Given the rust/corrosion, (and assuming it'll even come apart) that stuffing box has likely corroded, if not scored the shaft. Not worth taking a chance on it, and a new one will last a very long time with no headaches. Just my 2c

Cheers
Gary
 
PSR

PSR

.
Sep 17, 2013
117
Catalina 27 4743 MB Yacht Harbor, Richmond CA
Thanks again

Meriachee said:
Did you share these pictures with CD? It costs nothing to ask.

There's also another thread (look for PSS) on this site that references "split couplings" - yet another source of data.

There's also a Yahoo group for the 27, if you are not aware, and somebody has done this job, very likely with your specific installation. Just ask.

BTW, mine was WAY greener than yours. Once I get a coat of Brightside in there, the white will be white. It matters. :)

PS
I'd strongly urge you to get a new shaft, coupling, do the cutlass bearing, and either a new stuffing box or PSS. Given the rust/corrosion, (and assuming it'll even come apart) that stuffing box has likely corroded, if not scored the shaft. Not worth taking a chance on it, and a new one will last a very long time with no headaches. Just my 2c

Cheers
Gary
Click to expand
Absolutely I am going to do the whole job--coupling to cutlass bearing all new. Have been in touch with CD, etc. I'll probably be cutting the shaft this time tomorrow, then may be able to order the new parts with shaft measrements in hand.
 
dziedzicmj

dziedzicmj

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Aug 13, 2012
533
Catalina 270 Ottawa
Nothing much to add (to Gary's).

Your coupling is completely different from anything I have ever seen, so it is hard to advise on what would CD do.

Yes, I had a problem that CD sent me the wrong coupling (the holes for connecting bolts were 1/4" too close). But they resolved the issue quite quickly, when I told them about it. The only problem for me was the delay (about two weeks extra).

Once i got the correct coupling it fits like a glove; obviously they have the proper specs for them.

I fully support the idea of replacing everything at once (coupling, shaft and cutlass bearing). You should be fine for a good few years after that. Did I mention that I wold go for a SS shaft?

I VERY HIGHLY (I don't know how much more i could emphasize it) recommend replacing the stuffing box. Since you are removing the shaft anyway, this is the perfect timing. I went for the PSS, but if you want to go cheaper, you can get a new stuffing box and use goretex/teflon stuffing that would (should?) eliminate almost all dripping, as well.

Both Gary and I have C270s, so it is hard to recommend anything for your boat/motor combination. If you cannot find a direct replacement for the coupling you have, consider replacing it completely (including the transmission end) with something that is more like a current standard.

Good luck
 
B

brazenarticle

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Jul 8, 2012
146
Catalina 36 MKII North East
My coupling and shaft were terribly rusted too ( maybe not as bad, but close). I replaced all through marinemachining dot com. They make and stock many styles and types, the service was great, quick, and reasonably priced.
If you send them a photo I bet they could tell you exactly what you are dealing with.
 
PSR

PSR

.
Sep 17, 2013
117
Catalina 27 4743 MB Yacht Harbor, Richmond CA
Thanks again for thoughts & advice. The coupling on my shaft looks like a flexible coupling, and looks a lot like a federal coupling. I'm guessing that sometime in the last 33 years, this was a replacement for the original equipment. Otherwise, the transmission side looks like dziedzicmj's lovely, clean coupling. I'll be discussing this with CD and ordering once I have the shaft length. Once the parts are in, everything will be new, including the stuffing box.
 
PSR

PSR

.
Sep 17, 2013
117
Catalina 27 4743 MB Yacht Harbor, Richmond CA
brazenarticle said:
...I replaced all through marinemachining dot com. They make and stock many styles and types, the service was great, quick, and reasonably priced.
If you send them a photo I bet they could tell you exactly what you are dealing with.
Click to expand
Hi-
When you say replace all, did you have to replace the transmission?
Peter
 
Meriachee

Meriachee

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Aug 1, 2011
3,972
Catalina 270 255 Wabamun. Welcome to the marina
Yeah, Marek and Gary are actively working towards getting their engine bays featured on the "Sailboat Engine Bay Channel" with Mike Rowe. :)

"All" implies anything not nailed down, but rotating or supporting rotating, or impeding rotating, or preventing vitreous liquids from passing by, or through, rotating, um stuff.

Cheers
Gary
 
B

brazenarticle

.
Jul 8, 2012
146
Catalina 36 MKII North East
PSR said:
Hi-
When you say replace all, did you have to replace the transmission?
Peter
Click to expand
Fortunately no - I replaced the flange, shaft, stuffing box and cutlass bearing. Then I put on a CDI polyurethane prop.
All has been working well for two years.
 
Maine Sail

Maine Sail

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Feb 6, 1998
11,759
Canadian Sailcraft 36T Casco Bay, ME
#1 reusing an old rusty coupling rarely works. These are supposed to be an interference fit which often means heating one part and cooling the other to get them to fit together. Unless the fit of shaft to coupling is very snug the fit is incorrect.

#2 shafts and couplings are all slightly different sizes. For this reason most couplings are made slightly under sized. A competent machine or shafting shop first "fits" the coupling to the shaft. This is manual work and can take 20-30 minutes to get the "fit" just right. A layer of rust broken free is all it takes to destroy this "fit"..

#3 Once the coupling is fitted to the shaft it is then placed into a lathe, with the fitted coupling properly installed, and the run out on the face is machined true. YOU CAN NOT ORDER A PRE FACED COUPLING UNLESS THEY ALSO HAD YOUR SHAFT TO FACE IT TO.... A coupling needs be fitted then faced to the shaft it was fit to otherwise all bets are off... Any company selling mail order pre-faced couplings is simply selling you swamp land in Florida....

#4 Any competent shafting shop can get these couplings and properly fit and face them... Find a local shop that can do the work..
 
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