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Lasdrop Shaft Seal Failure

Discussion in 'Props, Shafts & Seals' started by DOCKMASTER, Jun 3, 2021.

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  1. C team

    C team Senior Member

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    PSS Shat seal.jpg
    The hose marked 1 is feeding raw water from the starboard motor. The hose marked number 2 is the crossover going to the similar T on the port engine.
  2. DOCKMASTER

    DOCKMASTER Senior Member

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    Thank you - much appreciated.
  3. DOCKMASTER

    DOCKMASTER Senior Member

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    So we did some closer looking at the rust bleed we are seeing is not coming out of the shaft seal, at least not directly. We got in closer and can see it is actually coming out of the fiberglass where the shaft log marries back into the hull. We even discovered a trace of water weeping in. No idea what the heck could be causing the rust but I need to get this figured out. Perhaps we got something in the stern tube when we had the boat apart? So I'm going to haul the boat, again. We will pull the port shaft to get a good look in the stern tube and see what's happening here. Then we will repair the fiberglass around the shaft log and see if we have an issue with the seal around stainless stern tube where it meets the fiberglass. Ugh!

    Here's a pic showing the underside of the shaft seal that is clean and then the rust bleed coming through the fiberglass.

    Port Shaft Seal at Shaft Log.jpg Port Shaft Log Rust.jpg
  4. Capt Ralph

    Capt Ralph Senior Member

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    Hard to imagine any metal component in-bedded in the hull rite there.
    Is that a screw hole? Broke screw in there Maybe?

    Just to cover ALL bases; From that rust stain, look straight up.
    Could anything be dripping from above?
  5. DOCKMASTER

    DOCKMASTER Senior Member

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    Possibly an old set screw or something, really I have no idea. Nothing above dripping and the rust is on the underside of the shaft log. One we haul out and remove the shaft we'll do more exploration to try and determine source of the rust.
  6. DOCKMASTER

    DOCKMASTER Senior Member

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    Boat is hauled and in the building for the winter. The port shaft has been pulled and we found zero issues. No contamination in the shaft log, no obstructions to effect water flow, bearing looks brand new (because it is). On the good news side, the seal that was installed at the start of the summer still looks great. We thought we were seeing signs of discoloration possibly from excessive heat but with a close up inspection and disassembly, it looks fine. So whatever caused the first seal to fail is a mystery. Perhaps something was in there, maybe it was set too tight, who knows. So it will all get put back together and the plumbing changed to put in the Tees vs. the crossover line and I’ll keep a close eye on it.
    Next week we will start the exploratory sanding and grinding to see if we can find the source of the rust bleed from the underside of the shaft log.
    TahoeJohn and Capt Ralph like this.
  7. DOCKMASTER

    DOCKMASTER Senior Member

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    We never really found any source for the rust bleed we were seeing. Not sure if it was from the first failed seal or perhaps we had contamination in there from the repower. It’s a bit of a mystery we will likely never solve. We ground it all out, sanded and re-glassed it all. We even plugged both ends on the shaft log and put 2 psi of air in it and it held for over 24 hrs. It’s now has fresh gelcoat and then a finish coat of the Interthane 990 we used on the whole engine room. Shaft goes back in next week and the seal re-installed. We will change the plumbing by installing the Tee’s vs the crossover line and I hope to be done with seal issues other than normal maintenance.
  8. Capt Ralph

    Capt Ralph Senior Member

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    What maintenance is expected on a zero maintenance log seal?
    :rolleyes::rolleyes:
  9. Capt Ralph

    Capt Ralph Senior Member

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    Did the original seal mfg come thru with any relief? I'm thinking a bad mark against them if not.
    You may want to show them this world wide thread.
    Yes, Iron Hand come to mind. I luv to bomb p****s.
  10. DOCKMASTER

    DOCKMASTER Senior Member

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    They rebuilt the failed seal and returned it to like new condition for me. Don’t think I could ask much more. They have also been responsive to phone calls and emails. Without being able to point to an exact cause of failure I’m satisfied with what they have done thus far.
    SeaLion likes this.
  11. Capt Ralph

    Capt Ralph Senior Member

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    Well, if you are happy. I guess that is what matters.
    Sorry that I still want to raspberry them anyway, for their product messing up on you.