Disconnect prop shaft from tranny before hauling?

[patrice]

Hi,

As said, I never heard anyone here doing this every fall.   All boats being hauled out.

But, if this would be required because of the hull flexing while being pulled out of the water and then having it stand on stands.

What about the hull during navigation in waves.  Having the hull going up and down.  Sorry but the water pressure applied on the hull is not equaly distributed at this situation.

But, not being a naval architect ....

[Fred Koehlmann]

Not a Naval Architect either, and while I'm sure that the hull does flex in multiple directions both in and out of the water ( on cradle), I'm thinking that the when on a cradle the primary flexing would be widthwise from the sides. Perhaps some lateral "sag" as most sterns hang aft of the cradle, but most of the weight is typically on the keel, so the length where the shaft sits is all "hanging" in the same section that could/would be sagging. (i.e it would all sag together, and thus the shaft would have little to nothing to worry about). Also, the shaft does not on its own, cantilever that much past the cutlass bearing.

Not sure, but this might be just some lawyer's legalese.?

I don't know of anyone in our marina that disconnects their shaft in the fall and then reconnects it in the spring.

[Noah]

Then of course there are those boats out there with flexible couplings.

[patrice]

Also, the question the other site was asked by an oday boat owner.

[Bill Shreeves]

Always good discussions here, thank you!  Still unable to find a link between Catalina and a recommendation to "decouple" the prop shaft.  I'll offer one last apology and blame it on a senior moment.  While looking, I did run across the link below which might be considered by some to be a reasonable source with the knowledge that finding it on the Internet doesn't make it so.

Regardless of the source, I've had time to ruminate on this and I've decided to decouple going forward for the winter.

My reason:  On my '87 C34, the shaft has approximately 3/16" clearance from the shaft log when centered perfectly.  If the shaft drops in the shaft log, far less space may exist and hull flex could put pressure on the shaft for an extended period of time while out of the water.  If the shaft is perfectly centered, I have a tough time thinking it could flex enough to move the shaft 3/16" over such a short span but, for the time it takes to remove 4 bolts, I'll be decoupling going forward.

I know the engine / shaft can drop this much because I discovered mine had when I replaced my shaft last spring after my first season with the boat.  The old shaft had rubbed on the log enough to show minimal wear.  I think the PO that re-powered the boat 12 years before never had it readjusted after it settled in with the new mounts.  I made the necessary alignment adjustments with the new shaft installation.

http://www1.udel.edu/db/Mas%20note/Notes/winter.boat.html

Thanks for sharing your thoughts,

Bill

[Stu Jackson]

Bill,

Have you considered supporting the inboard end, rather than having the coupling just hanging off the shaft?

[Bill Shreeves]

Have you considered supporting the inboard end, rather than having the coupling just hanging off the shaft?

Stu,
I sure have.  I installed a Federal flexible coupling along with the new shaft, stuffing box, cutlass bearing and prop last spring.  They're  pretty heavy and I could cause more harm than good if I don't.  I figure on using a block of wood with a V cut in the top to cradle the shaft just behind the coupling.  That's the next trip down.

-Bill

[Roc]

I forget where I heard about decoupling the shaft, it was about 18 years ago when I got the boat, and I've made it my decommissioning ritual every year since.  It may have been as part of the situation I encountered with a loud chattering noise......The first year I had the boat (new), I had a PSS dripless seal installed.  I was having problems with it and contacted PYI NUMEROUS times and did everything they advised.  A very loud chattering kept happening no matter what adjustments were made.  At the time, I had the OEM bronze shaft.  It may have been PYI that told me if the shaft is not true, it can whip and cause the seal to do that.  Putting stress on the shaft during storage would cause the shaft to bend.  They may have told me to disconnect the shaft during storage....So, I had the dealer contact CY to see if I could get a new shaft as part of warranty.  Believe it or not, Frank Butler called my house!!  Wife answered the phone and she said, "there's a guy named Frank Butler on the phone asking for you".....  I said "Frank Butler!!!!, he's the owner of Catalina Yachts!!!!!!!!!!!"  He said the shafts are all made within specifications and getting a new shaft was not possible....Oh well.....  I then had the local yard install a SS steel shaft and the problem went away.  I figured it only takes a few minutes to disconnect it after haul out.  In thinking about the situation, it does make sense.  No, I really don't notice that much difference when apart, but depending on who put up the stands, or any settlement of the ground structure, the flex of the hull isn't always the same year after year.  Every winter, I do notice gaps in doors or cabinetry that are not there when in the water.  In the spring, I put new lock washers on the bolts, reconnect the shaft and take it from there.  It's more like doing an extra insurance task.  It's not hurting anything, it can only benefit.

[Ron Hill]

Guys : For what it's worth, I've been to numerous boat shows (on land) and having helped with the Catalina setup, I don't recall any bit about reconnecting the drive shafts on any of the boats!!

A thought

[Doug4bass]

Long time lurker here. Excellent board....one of the first good ones.

Both my C-270 and C-385 came from the factory with the shafts uncoupled. Fl to.Ws.
Not sure if the factory had done an alignment or not. 

[britinusa]

Just had a recollection - it happens.

I recall reading an article about someone having their cutlass bearing replaced by a yard. The yard workers used a heavy hammer to encourage the bearing out with the bearing puller.

The hammering was suspect in damage found on the gear box.

Thoughts?

Paul

[Fred Koehlmann]

Hey Paul,

That's doing yard work on your cutlass, and not about "hauling". And a besides, once the yard pulls out the "heavy hammer", I'd worry. You shouldn't need it with a puller. I'm speaking from experience unfortunately. They forced my cutlass bearing out and in the process bent the original bronze shaft. I had to buy a stainless one at my own expense (glad to have stainless now tho).
Since no one seems to call you when they have an issue/problem, and they try to resolve it on their own (and they don't seem to know what to do), it seems you need to make all this clear ahead of time. I was luck my engine/gear were still OK.

Sorry, slight "yard work" diversion here.

[Bill Shreeves]

So, I finally came across the entry that I read about separating the coupling.   It's not from Catalina, it's in the Universal Operators Manual for M3-20B, M-25XPB, M-35B, M-40M & M-50B under the Lay-Up and Recommissioning.   Note, it was not in the original operators manual for the M-25 that was in my '87 34 but, its in the manual for the M-25XPB that was installed in 2005.

Excerpt from the manual:

PROPELLER SHAFT COUPLING
The transmission and propeller half couplings should always
be opened up and the bolts removed when the boat is hauled
out of the water or moved from land to water, and during
storage in a cradle. The flexibility of the boat often puts a
severe strain on the propeller shaft or coupling, or both,
while the boat is taken out or put in the water. In some cases,
the shaft has actually been bent by these strains. This does
not apply to small boats that are hauled out of the water
when not in use, unless they have been dry for a considerable
period of time.

[DaveBMusik]

Since these are all "decent size" engines, I wonder what their definition of a "small boat" is?

[Bill Shreeves]

Since these are all "decent size" engines, I wonder what their definition of a "small boat" is?

I wondered the same thing.  As I mentioned earlier in this post, I disconnected because its only a few minutes work and a safeguard like many things we do on/to our boats.