HELP installing my PYI dripless shaft seal

[truckman]

Can anyone give me a couple of pointers regarding my catalina 310. I bought the PYI shaft seal and a flexible coupling to install this weekend. I have read mainsails wonderfully detailed instructions and have come up against a couple of problems.

There is not very much room between my shaft log and my transmission coupling.By the time you put on the PYI seal and rotor there is only a small space to get the shaft lined up to the installed shaft couplings mated on the transmission coupling. My problem is how do you get the shaft onto the shaft coupling. If you look at Mainsails pictures you can see that there is very little room and so how do you get the shaft to go into the shaft coupling. There is no room to tap the coupling towards the stern. So I bought a split coupling and plan on tapping the shaft at the prop end with a block to push the shaft into the coupling. Is this going to hurt my transmission.

In mainsails directions he says not to hit the shaft towards the transmission when it is connected to the transmission, but in #4 he stated that you have to tap it home with a rubber mallet in order to get the shaft into the coupling. Is this a conflict and if not do I have to worry because I have a split coupling.

 

[peter_ms]

You should sand the inside of the coupling and the shaft and keyway
It should be a slip fit; not loose but it should slide without force.
You can use a light oil but dont let it get on the seal face.

I had a brass shaft orginally and have a stainless shaft now, but in each case I was able to force the shaft out of the coupling by inserting washers between the engine flange and the shaft inside the shaft part of the couplling.

There are setscrews in the coupling to fit into a drilled dimple on the shaft.

 

[Maine Sail]

In mainsails directions he says not to hit the shaft towards the transmission when it is connected to the transmission,

This is what I describe first on my web site:

3) After some initial tightening, and with the bolt pressure still on the shaft and coupling, you may need to go outside the boat and strike the prop shaft towards the bow, yes the bow, with a dead blow mallet to help break it free. This is not a pounding with the mallet, just a strike. Use a scrap piece of maple between the mallet and the shaft to prevent potential damage to the end of the shaft from the dead blow. Then re-enter the boat and continue tightening until the coupling is off the shaft. This action tends to break free the coupling some times. Do not over do it as damage to the transmission can ensue.

but in #4 he stated that you have to tap it home with a rubber mallet in order to get the shaft into the coupling. Is this a conflict and if not do I have to worry because I have a split coupling.

This is what I describe in #4:

4) When re-installing the shaft you should get it started with the machined in "lead" then lightly tap it home with either a rubber mallet or an oak or maple block protecting the shaft, and a hammer. For this job you'll need two people or many trips up and down the ladder. Tap it in while looking in the coupling holes until you see the dimples for the set screws. Don't over do it cause backing it off is more of a pain than driving it in.


Generally speaking split couplings are nice but are usually longer this is why my 310 still had the solid coupling on it. You can install the coupling bolts finger tight then line up the shaft & key and then tap it home..

You should sand the inside of the coupling and the shaft and keyway. It should be a slip fit; not loose but it should slide without force.

Peter,

I don't know where your information came from but it's certainly not in line with ABYC P-06 or standard industry practices for straight couplings.

Please, please, please do not "sand" the inside of a coupling for a "slip fit" for the desire of "without force".

The machine shop I use, & the largest shaft and prop shop in the North East, fits the coupling to the shaft with an interference fit or light press fit, this is proper.

On a properly machined shaft, without any anti-corrosive agent like Tef-Gel, it will slide on about a 1-2cm of the way before you experience some solid resistance. This initial fit is often referred to as "lead" meaning they, the machine shop, give you a little bit of leeway to get the shaft started into the coupling.

The coupling and shaft are machined to exacting tolerances so there can be absolutely no wobble or play between the shaft and coupling. Any wobble will cause excessive shaft, key and coupling wear and could eventually lead to a failure. I have seen this on more than one occasion. It's no fun to lose a shaft out the shaft log when you put the boat in reverse..

ABYC P-06
6.5.5.1 Transmission Coupling End - The coupling end
of the propeller shaft and/or the coupling shall be sized to a diameter that permits a maximum clearance of .001 in. (.025 mm). See Table IV and SAE Standard J756, Marine Propeller Shaft Couplings, Tables 4 and 5.

ABYC describe the maximum "slop" or fit as a .001" BUT this refers to split coupling sthat clamp the shaft not straight couplings which are to be press or interference fit. If a solid coupling does not require a light tap fit then is is not fitted properly and you will likely have issues down the road. This is why it is advised to always have your coupling professionally fitted & faced to the shaft.


Checking face run out.

 

[peter_ms]

Maine Sail
That may well be the case... but the sanding was only to clean off corrosion and when brand new it did not need force.
This is a 26 HP motor and this coupling is way over what is required.
The coupling slips on without force but is not loose.
If you would rather hammer it on; be my guest.
Peter

 

[Maine Sail]

Maine Sail
That may well be the case... but the sanding was only to clean off corrosion and when brand new it did not need force.
This is a 26 HP motor and this coupling is way over what is required.
The coupling slips on without force but is not loose.
If you would rather hammer it on; be my guest.
Peter

Peter,

I was just trying to help you and others not get into a bad situation.

If you want to ignore industry standards for fit on your own boat that's ok, but please avoid passing on potentially dangerous advice to others (sanding rust away). If you do, you honestly can't expect it to not be addressed with what is the proper course of action and what is in-line with industry & ABYC standards for prop shafting.

I do have experience with seeing failed couplings due to fit issues. I worked in boat yards in my younger days and was the grunt who was small enough to be doing most of the stuffing boxes and shafting repairs (really hated that job).

A friend also manages a local shafting shop here in Maine so I do intimately understand the process and have physically watched the entire process from start to finish, had my hands on the machining tools, and played with the calipers and dial indicators, it's where the shafting pictures came from, my friends shop.

It is not only the coupling that will suffer from a sloppy fit it is the key, key way, shaft and set screws. If you are cleaning up "corrosion", that is, and was very likely, your "fit". Good boat yards around here will not re-use a used coupling due to the loss in fit as it is not worth the liability. A new fitted and faced coupling is usually under $100.00. A new shaft with coupling starts at $400.00 and goes up from there. Whey potentially ruin a good shaft?

The fit should be a light tap fit or a light interference fit as my prop shop manager refers to it as, not "hammer", and I never used the word hammer anywhere. If you choose to not believe that a light tap fit or light interference fit is how good shops do it, then that is fine.

If your coupling when, "brand new it did not need force" was fitted and faced by a competent shafting shop it probably should have been sent back for a better interference type fit.

I have ordered and used shafting and fitted and faced couplings from Catalina Yachts (good prices BTW), required a light tap fit. Also from H&H Prop, requires a light tap fit and NE Prop whic also requires a light tap fit. Hamilton Marine, requires light tap fit. Donovan Marine, requires light tap fit. Brackett Machine, requires a light tap fit..

Every once in a while, when working in the boat yard, we'd get one that just "slid on" far to easily and it would be quickly sent back to the prop shop. Of course this was in the days of Tobin Bronze shafting and they went on slightly easier than they do with the Aqualoy or Nitronic shafts but still always required a light tap fit..

In order to re-use a coupling the interior should look at least this good. If you have a layer of rust you should pitch it and get a new coupling and have it fitted and faced.

Sorry you did not like my references to the industry accepted practices and standards.

Old rusted coupling vs. newly fitted and faced:
[ttyouyube]http://www.youtube.com/watch?v=onmkD4PnRlk[/ttyouyube]

 

[paulj]

truckman

While the boat was out of water I had to have a new shaft and strut bearing installed in 2007, so I also installed a PPS at the same time.

I do not have any knowledge of the fit because I was on the prop shaft end tapping with a big brass hammer against a 2x4 on the shaft.

The mechanic was at the transmission joint and as I recall we did not have any problem except he didn't install a vent hose but I did later.
Now would be the time to check the for forward and aft play and looseness of bearings just to see how much play you have in the transmission.
You could put a block and shims between trans flange and trans so no shock to bearings etc in transmission.
Just some thoughts.

paulj :troll:

 

[Witzend]

Paul, what size Dripless did you install? I know it is a 1" shaft, but not being at the boat right now I don't know what the shaft tube OD Dia is. I'm reading 1.65" for the ID of the flex log and the same for the OD of the collar for the existing packing seal that I do have with me. This is confusing since the PSS dripless systems seems to be sold with 1.5" and 1.75 increments, no 1 5/8"????

 

[paulj]

Witzend

Still in Whistler 2010 Winter Olympics be home March 2 2010.
Free drinks and food everytime Canada wins a gold medal.
Will measure when I get back.



paulj :dance:

 

[rpwillia]

What is the procedure?

Now would be the time to check the for forward and aft play and looseness of bearings just to see how much play you have in the transmission.:troll:

PaulJ, What is the procedure for checking this? I volunteered to help Witz re-install his transmission as I wanted to learn and see it for myself (even if if is not a fun job), but this is an area I know little to nothing about.

For my $0.02 I am OK with a little drip off of my shaft, and don't see the need for a drip less shaft.

 

[Witzend]

Hey, Ray I'm going to try to drill out my strut and epoxy in my new cutlass bearing in proper alignment on Friday. If all goes well I will be ready to put her back together the following weekend, weather permitting. Not sure what your schedule is, but you are welcome to ride shotgun. Yea, I get your drift about the drippless.