Dripless Shaft Seals

GaryG · Post by **GaryG** » May 30th, '07, 16:53

I have been using Tides Marine original shaft seals (uhmw polyethelene body / nitrile lip seal), and am wondering if I should replace them when I haul in a week (I at least need to replace the hoses, and lip seals).

Tides has a newer composite body lip-type shaft seal that looks more robust than the older plastic bodied seals. I also recall that some of the faithful had a preference for PSS (face seal) dripless shaft seals.

What recommendations do you all have ?

Thanks!
Gary Gibson

CaptPatrick · Post by **CaptPatrick** » May 30th, '07, 18:15

Gary,

You know my stand on both Tides, Strong, and any other than PSS-PYI...

Shift over and breathe a sigh of relief.

Br,

Patrick

Kevin · Post by **Kevin** » May 30th, '07, 20:28

I have the ones Pat speaks of. They seem to be pretty tough. No complaints on quaility.

thuddddddd · Post by **thuddddddd** » May 30th, '07, 20:29

Mine work awesome, on the dock stands

mike ohlstein · Post by **mike ohlstein** » May 30th, '07, 20:33

So you're saying that no water manages to leak out of the boat through them......?

Kevin · Post by **Kevin** » May 30th, '07, 20:37

Do they keep the oil inside the boat?

thuddddddd · Post by **thuddddddd** » May 30th, '07, 20:55

all ya;ll can screw. I come here for support and this is what i get. humpppp. crap like that I can get from Kathi. youz be dicks(and I don't mean that dick, capt dick)

Tony Meola · Post by **Tony Meola** » May 30th, '07, 21:22

Capt. Pat

Did you ever use the Norscot seals? I am told they don't need a flow of water to keep them cool. The Cummins dealer I am talking with about a repower is recommending them but I never heard of them. Tony Meola

CaptPatrick · Post by **CaptPatrick** » May 30th, '07, 22:12

Tony,

I haven't used Norscot Seals, but I wouldn't be in favor of them either.

Here's a basic dialog on the Norscot system:

The Norscot seal uses lip-type oil seals pressed into bronze housing. The
bronze housing is machined to a bearing tolerance and clearance to fit each
size propeller shaft. The shaft and bearing surfaces are lubricated with
the systems self contained oil supply in a resevoir and the lip-type seals
on each side of the bearing surface keep the oil from leaking. Water can
not enter the bilge through the seal as long as oil is visible in the
resevoir and tube. There are no adjustments necessay with this seal system.
The owner (operator) should monitor the oil level in the resevoir and add
oil if necessary during operation. After about fifty hours of running time,
the plug on the underside of the housing should be loosened to allow the
dark oil to drain into a pan or oil absorbent pad (about 1/2 cup) and
re-tighten the plug.

If a propeller shaft is pulled for any reason, the oil should be dained
from the system. The Norscot seal must be removed by loosening two hose
clamps and re-installed per the original installation instructions. The
temperature of the housing when cruising should not exceed 140 degees
Fahrenheit.

Every installation is different, but one should expect over 1,000 hours of
run time before the seal will show signs of seeping oil into the bilge. You
can still run hundeds of hours until a scheduled haul-out to replace the
lip-seals. There is no seeping of oil when the shaft is not rotating even
if the seal lips are worn.

Just what I wouldn't want: Another couple of ATF filled resevoirs to mount in a limited space. And you've got to babysit them every fifty hours to dain old oil? Gotta' be overhauled after 1,000 hrs? No thanks!

I'm still a PSS-PYI fan.

Ask Randall how much time he's spent on his PSS seals...

Br,

Patrick

Kingfish · Post by **Kingfish** » May 30th, '07, 22:19

When my boat was repowered in 1998 by a previous owner the PSS-PYI seal system was installed.

No problems to date other than a service that neither previous owner did. No big deal, move the collar back a fraction of an inch and your good to go.

I did repalce the marlon nipples in the collers for the cooling with brass as I didn't like their looks.

Don't know to much about the Norscot system other than what I've heard. A resovoir with ATF (transmision fluid) that cools there seals.

bob lico · Post by **bob lico** » May 31st, '07, 04:26

this is really not a topic for discussion the pss seals totally monopolize the the utimate shaft log seal.99% of the 2007 major boat builders use them on there diesel powered boat whats there to compare.i used clear reinforced hose from my gear cooler to the pyi-pss seal no need to be a rocket sciencetist with the engine running you will see water flowing.put that on your check list along with checking your gear oil as a mandatory periodic maint.

randall · Post by **randall** » May 31st, '07, 04:44

so far so good...and you can run them at low speed dry.... i have come in on one engine 3 times with no apparent problems..........going fluke fishin' today on the sixty foot bertram......as long as i dont have to chip in for fuel....those some expensive fluke

Charlie J · Post by **Charlie J** » May 31st, '07, 04:47

mike
looks like your out, randall just took it up a notch

Bruce · Post by **Bruce** » May 31st, '07, 05:48

Any of the shaft seals will work.

Which one works the best with the least amount of worry? The PSS.

As Randall stated at slow speed the pss seals will work fine because the sea water around the log is enough to cool them. Too much forward speed and the water will pull away and thus the cooling will stop.

Seals for sailboats and other slow moving craft don't use a cooling line.

One thing on maint. once a season check the fittings and hose to make sure water flows well.

Also if the flow of water from the engine is too strong, the seals can and do throw water at high rpm.

Never use oils of any kind while assembling. Use only liquid soap.

Rawleigh · Post by **Rawleigh** » May 31st, '07, 08:30

I've had them for 6 years and wouldn't use anything else. I inspect them occassionally and that is it. The boat stays in the water all year round, and in the Spring when I dewinterize the bilge is dry!!

Tony Meola · Post by **Tony Meola** » May 31st, '07, 19:54

Capt. Pat and all others, thanks for the input. I don't really like the idea of another place for my bilge to collect oil. He was trying to sell me on the point of not needing to worry about the tube clogging and starving the shaft for water. The bilge has been clean for over 35 years, I would hate to have something like this mess it up. Tony Meola

Charlie J · Post by **Charlie J** » May 31st, '07, 20:20

like rawleigh, had mine for 7 years no problem at all

Doug Crowther · Post by **Doug Crowther** » Jun 1st, '07, 12:53

The cooling line for my PSS's comes off the back of each engines aftercooler. The water has been thru the engine strainers, coolers,etc. I have never had a problem with clogging. The only issue I have had is the stainless disc sliding up the shaft and thus reducing the tension between the stainless and carbon faces, and it did leak then. Like them a hell of a lot better than stuffing boxes.

It's freaky when winterizing with the 50 below antifreeze and puddles develop under the boats shaft logs.

Alex · Post by **Alex** » Jun 2nd, '07, 07:06

Kingfish, I was reading the PSS-PYI installation instructions and ran across this.

Do not tighten or replace the installed nylon hose barb fitting with a metallic fitting (bronze or stainless steel).Metal hose barbs will damage the carbon and destroy the PSS.

I don't know if that's what you replaced with brass nipples, but I thought I'd pass this along in case it affected you.

Alex

RussP · Post by **RussP** » Jun 2nd, '07, 10:49

Kingfish, you voided the guarentee and are at risk of sinking with the brass nipples. I know this first hand as a 32' Lhurs was hauled because a surveyer thought he was smater than the engineers at PYI and recomended changing them to brass. The result was the carbon blocks cracking and complete faliure of the seals! PYI voided the guarentee and it cost a bundle to remove the running gear purchase new seals and reinstall the gear. PYI couldn't believe the surveyer recomened this and I believe his insurance company payed the bill. This is proably the only way these seals will fail.
RussP

GaryG · Post by **GaryG** » Jun 3rd, '07, 16:51

Looks like the PSS-PYI face seals is the way to go! With the level of recommendation here, PYI should be a supporter of the B31 board.

Their shorter length will also provide for much easier inspection/service in my B38 as the entire unit will be located in the aft lazzeret (the tides lipseals require a long hose section and the face of the seal is currently just inside the aft engine-room bulkhead).

Thanks!

Gary Gibson

bertram31.com

Dripless Shaft Seals

Dripless Shaft Seals

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