Help identifying dripless seal and shaft size

[GILow]

Hello Cruisers,

I have attached a pretty hopeless photo (the best of nearly twenty I took with my phone) of our dripless shaft seal. It is probably close to ten years old so I will replace it to be safe. (The seal, not the phone, I think the phone maybe older!)

From the rather hopeless picture I am hoping someone can recognise the type, or suggest a replacement type that would suit. It is not the sort with the extra small hoses to supply it with raw water (I think that is their purpose, I don't actually understand what they do.).

Also, the shaft has me confused. I assumed it was 1.25 inch diameter, but it turns out to closer to 36mm (or about 1.4 inches) (measured using the spread of a shifting spanner, not an exact tool but all I had available at the time.) I don't believe that is a standard size, at least, I have not run into it in my reading so far, so if someone can shed some light on this for me I would be very grateful.

Matt

P.S. Does anybody else find that when they try to attach a picture, the first time they hit upload they get a page not found error, but it works the second time? It happens to me every time, no matter which computer I use. Weird.

[banjoship]

Matt,

It looks like a PSS, but I have never seen one so tarnished (or is it rust?). The steel bits on a PSS are all high grade stainless. The lack of hose barbs is common on the earlier ones fitted to slow speed shafts.

If it is not leaking now, it means the rubbing surfaces are ok. Recommended maintenance is replacement of the bellows every 5-6 years. PSS sell a kit which contains bellows, 2 o rings for the rotor , and the 4 grub screws which hold the rotor in place. These screws are not intended for reuse.

Instructions are on the web at the PSS site.

To order, you need accurate measurement of shaft and od of stern tube. I would be surprised if your shaft is 36mm, would have expected 38mm, or 1 1/2" .Maybe time to get a set of vernier calipers, they are cheap.

The Australian distributor is in Melbourne, forget the name, but any chandler should be able to order. Suggest you order asap as there can be delay in supply. I don't think you have time now, but you can buy the kit online in the US for a lot cheaper than here. Another example of aussie ripoff.

Lee

[Pato]

Yup sure looks like a pss a tired one Make sure to inspect faces of the sealing surfaces for pitting or scoring I have found with most pss seals the Carbon end tends to Pitt and rot

[barnakiel]

I think you will want to clean up and paint the whole area. Makes spotting any issues so much easier.

The shaft dia use calipers sometimes the little 0.04 mm makes big difference ...

b.

[Dsanduril]

Looks identical to my old shaft seal, which was a PSS. Down to the dark part on the stainless collar, which were scorch marks from having it run dry at one point (and yet it still kept the water out and didn't drip). I think (someone can check me on this) that PSS stopped making them without the hoses because of this. The simplest version uses one hose that is simply a vent run up above the water line. That way if your stern tube dries out (run up on a beach, haul out, diver's air bubbles) it automatically fills back up with water as the trapped air can vent out the hose rather than having to go down the shaft tube.

To order a new one you'll not only need the shaft diameter you'll also need the diameter of the stern tube (where the bellows attaches) as they make units with different bellows diameters for the same shaft diameter.

PSS Shaft Seals: Type 1 | PSS Shaft Seal

[Jim Cate]

Only other thing, Matt, is when you do replace it, try and find hose clamps of the sort NOT having perforated slots for the worm drive engagement, rather the embossed "threads". The latter are much less prone to fail suddenly... something to be avoided in these critical areas!

Cheers,

Jim

[GILow]

Thank you all, excellent advice and help as always.

Please be reassured that:

a) I am tossing the whole lot and starting again. I just think it is too old to even contemplate keeping any of it. Dsanduril's remark about the apparent overheating mark just reinforces that point.
b) I have a set of calipers, I just forgot to bring them to the boat, I promise I would never use a shifting spanner for this sort of job. I reckon Banjoship might be right in that it is probably 1.5" shaft and I just measured really badly.
c) Jim, thank you for reminding me about the hose clamps, I had read that elsewhere on CF and completely forgotten about that.
d) I will paint the area as you suggest Barnakiel, actually, I am modifying the battery bank to make the whole area more accessible and easier to maintain. This was all hidden under one of the house batteries, NOT good in an emergency.

Happy sailing all, hope those of you in the Northern hemisphere are not snowed in too soon. We have been pummelled with 30+ knots for the last few days, so, call me a chicken, but I am staying in the pen for a while and doing maintenance stuff.

Matt

[GordMay]

Originally Posted by Jim Cate

Only other thing, Matt, is when you do replace it, try and find hose clamps of the sort NOT having perforated slots for the worm drive engagement, rather the embossed "threads". The latter are much less prone to fail suddenly... something to be avoided in these critical areas!

Cheers,

Jim

AWAB (ABA) Non-Perforated Marine hose clamps
➥ AWAB LLC
➥ AWAB Hose Clamps

[GILow]

Originally Posted by GordMay

AWAB (ABA) Non-Perforated Marine hose clamps
➥ AWAB LLC
➥ AWAB Hose Clamps

Thank you GordMay, any chance your encyclopaedic knowledge could tell me where to find those in Australia or what to ask for? I am a bit close to haul out to be sure of getting them shipped in time.

Matt

[Dsanduril]

Check out Anzor:

Hose Clamps - 316 Stainless Steel Non-perforated Hose Clamps | Anzor Australia

[GILow]

Originally Posted by Dsanduril

Check out Anzor:

Hose Clamps - 316 Stainless Steel Non-perforated Hose Clamps | Anzor Australia

Wow, it's like when I worked in government and had a full research team to help me. Thanks so much, that's just what I need.

Matt

[delmarrey]

When I do a close up it doesn't look all that bad, just dirty. You have something dumping crud all over the top of the thing. A 1.4" would be closer to 1-3/8" which would be about right for a 42' boat.

It's no big deal about the hose clamps, PYI the manufacturer (right up the road here), supplies hose clamps with the units, which are the standard SS clamps. The new ones all come with a vent/injection fitting now. But if it has a close tolerance stern tube, it's best to run injection vs the vent option.

At 10 YO the rubber is probably starting to get hard and doesn't load the seal as well as it should anymore. Yeah, I would replace it!

BTW it's common now to put and extra ring around the shaft to keep the SS seal in place in case the set screws work loose. A round zinc or even a hose clamp works OK. Even PYI sells them now. Heck, they might even supply them with now, but don't know. Haven't bought one for a couple years.

[GILow]

Delmarrey, I am not sure I'd let people know PYI are around the corner, you mind find you are being begged to go and get a seal in a hurry for someone with their finger in the leak.

There is a lot of crud around from flushing the stinky stern tanks, all sorts of goop came out and some of it stuck. Eeergh... but once I have the seal off I am going to clean the whole area with a stiff brush and detergent before painting it as per Barnakiel's suggestion.

I got down to the boat with the callipers yesterday, and the shaft turned out to be 1.5" like Banjoship expected, which is a pain as there are many more 1.25" secondhand propellors around than 1.5". I really wish it HAD been 1.25", I am pretty sure that is strong enough for my engine.

Now I am trying to work out whether the stern tube is 2" or 2.25", that's harder because I can't get the calipers to it without removing the seal, and the boat is still in the water. So I am going to use a piece of string to get the circumference instead, and work out the diameter from that. Horrid job, headfirst in the bilge and it is a LONG way down to that point in the boat. Still, once done properly, I guess I should have 5 to 10 years without problems.

Matt