Lasdrop Shaft Seal Failure

I installed 2 new Lasdrop shaft seals when we repowered last year. They have less than 50 hrs run time on them. Worked fine for the short season last year. Just ran the boat for the first time this year. About 3 miles of idling to fuel dock and back is all. Went in engine room and port shaft seal is leaking very badly. Bilge pump kicks on like every 30 seconds. Stbd seal is fine and look like new. Port seal is rusty as hell and looks 20 years old. Tried all the customer support numbers listed on Lasdrop website and no answer, just rings. And yes, this was before 5pm EST. What a PITA!
Now I have to haul and replace this thing just as season was starting.
Has anyone else had issues with these? Mine are the Gen II series which are supposed to be their best seals. I don't have time to wait around so ordering a complete new seal and will figure out the issue later. Needless to say but I'm not a happy camper!
And yes, we got the shaft temporarily wrapped and taped up to stop the leak and clamped on a split hose hose as additional protection.

Thanks guys. No, clearly the rust has been happening over time, but it is odd that only one side. And it wasn't leaking sitting there. It's almost like it is rusting from the seawater side. And the leak is very substantial so not just from from some dirt or a little oil. It is apparent that something failed and just let go.

Anyway, new seal assembly should be here tomorrow and we will haul early Tuesday and see what we find.

Don’t believe it is electrolysis. There is clearly corrosion and rust. We’ll see here in a few days when I get it apart. I also don’t see how it could be from engine millings given it is on the raw water side? I guess there could have been some crap in there somewhere? It is also possible we somehow contaminated the shaft area or inside the stern tube but we were pretty careful and waited to install the seals until the end of all the other work. I’ll post some pictures and what we find when we haul on Tuesday.

I’m not positive about anything and didn’t indicate any positivity. I was simply pointing out that since the raw water side doesn’t contact much inside the engine (except H/E and cooler) it would be odd.
And since all the metal components of the seal are supposed to be non-ferrous there shouldn’t be rust even if there was electrolysis. I could see perhaps some erosion, pitting ,etc. But shouldn’t be rust. So it would seem there is either contamination or perhaps a component that might not be non-ferrous.
Anyhow, no sense in continuing to speculate when I should no more in a few days.

So we got the Port seal pulled and what we found is pretty ugly inside. I was able to speak with Lasdrop and shared these photos with them. What I didn't realize is with these seals they want the shafts rotated at minimum every few weeks to avoid oxygen deprivation to the 316L components. Yes, the instruction sheet mentions this and I missed it. With all the issues from COVID and travel restrictions I haven't used the boat since last July. And I cannot recall us ever rotating the shafts. So it is highly likely the shaft has not been rotated for 11 months. It is certainly possible we got some contamination in there as well from an unknown source. What is also interesting is the starboard seal looks like brand new inside. So why we experienced oxygen deprivation on one side and not the other is a complete mystery. Regardless of the apparent condition of the starboard seal it is being replaced too. Hoping to be back in the water tomorrow.

Lasdrop says they can reface and rebuild these seals for like $100 so I'll send them both back and get them rebuilt to have for spares.


Well live and learn is the best lesson I can take away from this one. I hope this info helps someone avoid this.

By couplings I assume you mean the shaft to ZF Gears couplings? They are all new and in great condition. No issues with the couplings

I hear you but they are certainly marketed to recreation. Had I known about that I probably would have gone with something different.