Propeller shaft seal compression amount

[pr2501]

I have Seaview progress PSS shaft seal (type A). Manual says I have to compress it for 3/4" or 20 mm for 1 1/4 shaft diameter.
At me seams to much because I am pressing with almost all my power. Whats yours experience?

[Manateeman]

This is a face seal...stainless against carbon. A lot of pressure is NOT required.
We can think of a number of reasons why it’s not working. Things spinning loose..something between the surfaces... the surfaces not in plane when rotating..cracks..hair..dirt..broken part inside..on and on.
We suggest you take it apart, clean and examine and reassemble.
If this works, send us a pizza gift card...
We use a Last Drop seal...very similar.
The manatee crew.

[pr2501]

It's new. Never used before.
It has to go in the water ttomorow for the first time.
From the feeling I would say 1 cm is enough.

I wiill call in the shop tomorow.
Maybe I am mistakiing .

[ItDepends]

Are you trying to make it 3/4” long? Or just 3/4” shorter than it’s relaxed length?

[mwardmoeller]

I've used the PSS on my 1" shaft (Wetsnail 32) for many years. During my repower this spring I renewed mine and seem to recall that 3/4" compression is used for both the 1" and 1-1/4" shaft. It IS challenging to hold that compression.

My trick is to cut two wooden boards (scrap lumber...maybe 3/4" X 1" or 2") to act as shims. The are cut to length to bridge the gap between the PSS collar and the transmission flange. I make one end of each board is slightly tapered. The "long" part of taper to the opposite end equals the relaxed length plus the 3/4" you need to compress. I compress the bellows somewhat and work in the "shim." Some light taps with a hammer on the side of the SHIMS works the collar down the shaft. Easy peasy.

The collar is held in place and the four set screws (two in each hole) and be easily set..

Hope this makes sense. It has worked for me multiple times.

Good Luck.

Mike

[Sailmonkey]

The 3/4” compression is what it calls for. I was never able to get that much compression while upside down with my rib cage flattened and holding an Allen wrench. No problems for 12 years.

[Manateeman]

OK...so NOW you tell us it’s new. Still doesn’t need a huge amount of compression...but...it may take time to seat itself. Don’t give up if it leaks a bit when new. This might stop soon.
If you think the set screws are slipping, you can mark the shaft and dimple it with a drill after you move stuff out of the way...don’t wreck the set screw threads.
Everything will turn out ok if you have followed the instructions.
We’ve changed a shaft seal out while the boat was in the water. Crazy manatees.
Good luck. Mark

[Boatyarddog]

Originally Posted by Manateeman

OK...so NOW you tell us it’s new. Still doesn’t need a huge amount of compression...but...it may take time to seat itself. Don’t give up if it leaks a bit when new. This might stop soon.
If you think the set screws are slipping, you can mark the shaft and dimple it with a drill after you move stuff out of the way...don’t wreck the set screw threads.
Everything will turn out ok if you have followed the instructions.
We’ve changed a shaft seal out while the boat was in the water. Crazy manatees.
Good luck. Mark

Gem me a packing gland anytime!
Dripless...
Lol
BYD

[Frank 101]

Similar to the two pieces of lumber thread, but easier. Try this - measure from the end of the seal to the end of the shaft. Cut a piece of timber (say, 19x30mm) that length less 3/4”. Place a flat head screwdriver vertically at the end of the shaft. Put one end of the piece of timber against the seal and the other against the screwdriver (which is leaning backwards). Straighten the screwdriver and the seal will compress. Slide the timber down the screwdriver till it sits in place with the seal compressed. Remove screwdriver and the timber will stay there. Do up the Allen screws and remove timber. Job done easily.

[Squanderbucks]

My solution was to measure the "relaxed" distance from the Transmission coupler then Add the needed compression - ie 3/4". Cut a piece of PVC Pipe of 1-1/3" inside diameter to that longer length.Then cut out a strip one one side that will let you snap the PVC over the shaft. A little rounding or bevel on the end facing the Shaft Seal helps it go to place. All along the cut out strip area as well. The Finished pipe will have a "C" shaped cross section.
Pop it over the shaft.
Leave it in place while you tighten things up. Remove it and store it somewhere onboard in case needed again sometime. Mark it with Sharpie for twin engine boats as often Port and Starboard may be a little different.

[pr2501]

Thank you for the replies.

[Rumrace]

I was about to say it’s not a job for human hands but someone beat me to it. We used a truck brake clamp and blocks to follow the instructions

[wrwakefield]

It was a difficult task on our 1 3/4" shaft as well.

I marked the shaft in advance where the forward end [in relation to boat] of the SS collar would be when the bellows was compressed per spec.

To finish the compression, I installed a shaft anode next to the SS collar. Then I drove wedges between the anode and SS collar to move the collar into final position.

Next I secured the SS collar in place, and then secured the anode against it [as a safety back-up, not an anode...]

In case this is useful.

Cheers! Bill

[osprey877]

Originally Posted by Manateeman

If you think the set screws are slipping, you can mark the shaft and dimple it with a drill after you move stuff out of the way...don’t wreck the set screw threads.
Mark

Put a hose clamp around the shaft and leave about a 16th of an inch space between the clamp and the collar. This will give you a quick visual check as to whether the set screws are slipping and a failsafe in case they do.