New PSS shaft seal installed

[Stuart 28-2]

I installed a new shaft seal along with new prop drive shaft and new strut bearing. The solid shaft coupling was also cleaned up / checked for fit by the shaft maker ( General Propeller Company).

The installation went smoothly enough except I was surprised how difficult it was to compress the seal. The instructions are clear enough - for 3/4" drive shaft - 20mm of compression. I was only using thumbs against the collar but had a ledge in perfect spot to lever off with all fingers. It took everything I had to get it to 20mm. I had to have someone else tighten the set screws in the collar. Does this sound normal?

Also, are the hose clamps on the carbon graphite end supplied as tight enough? I tightened a dash but want to leave it alone if intended as set to begin with .

 

[Dave G.]

I just did a "tune up" on my shaft seal which included a new bellows which was way more stiffer than the old one. I had to use some mechanical force to get it compressed all the way and be able to tighten it down while holding it in place. I believe they have beefed up the bellows to be sure it holds a seal. Mine has been on since April and not even a drop so all is good. Not sure about the clamps being supplied as tight enough. I tightened the hose clamps pretty tight one handed with a 1/4" drive ratchet. Not sure of torque specs but at least as tight as a cooling hose on an engine if that helps. Don't forget to "burp" it when you splash !

 

[Stuart 28-2]

I just did a "tune up" on my shaft seal which included a new bellows which was way more stiffer than the old one. I had to use some mechanical force to get it compressed all the way and be able to tighten it down while holding it in place. I believe they have beefed up the bellows to be sure it holds a seal. Mine has been on since April and not even a drop so all is good. Not sure about the clamps being supplied as tight enough. I tightened the hose clamps pretty tight one handed with a 1/4" drive ratchet. Not sure of torque specs but at least as tight as a cooling hose on an engine if that helps. Don't forget to "burp" it when you splash !

Okay, good to see. Thanks.
The new one has a vent tube. I thought that was to do away with the need to burp it?

 

[Loren Beach]

Their newer model of this sealing system has incorporated a vent tube for a number of years. So, if yours has this, the tube takes care of venting any entrapped air from launching the boat. Be sure to study how to route and protect the vent tubing.

Our older (circa 1995) PSS seal does not have this tubing in the front of the face piece. We have replaced the bellows part, however. The factory, probably concerned about liability, recommends replacement every 7 years or so, IIRC, but many owners seem to wait considerably longer. Just closely inspect that bellows as it ages, for cracking in the surface rubber material. And, remember that your insurer may want to see a record of this sort of preventative maintenance, when handling a claim for flooding/sinking.

And also, "just one more thing" as Steve J used to say. IF the engine is shaking or moving too much, some water will spray out from the seal, when running. This almost always will call for an alignment, and almost always reveal that the engine mounts are in need of replacement. (Collapsed or broken mounts are endemic to engines beyond a couple of decades of operation. It's easy to blame alignment for failure to smooth out the running gear, when it still has ancient engine mounts.)

Clamps: check out "AWAB" clamps. Stronger, with rolled edges. https://www.new-line.com/clamps/bol...lamps/euroseal-316-stainless-steel-gear-clamp
Lots of sources, but the picture in this link is nice.

 

[Dave G.]

The new one has a vent tube

Yeah the vent takes care of that need, mine is old without the vent.