Thruster shear pin replacement

[sjreib]

There is much discussion about the dreaded thruster shear pin replacement on this blog and I'd like to be prepared for when and if I need a pin replacement on my C28. Is putting in an unbreakable stainless steel replacement pin a wise idea and if so where can I get these? Is the motor protected by an easier to replace fuse and/or propeller?
Just trying to live up to my Boy Scout motto of "Be Prepared"
Thanks for your help

 

[Phil Nersessian]

I joined the Stern Thruster Shear Pin Replacement Club today on my C30. I also debated using an unbreakable shear pin and decided against it. Although it's breaking was, I think, too easy, I didn't think it wise to go unbreakable at this point. It took me about 6 hours to replace the pin, I think if I have to do it again it will take me 2-3 hrs. Like about everything else I have repaired on the boat, the repair itself isn't bad, it's access. If I had easy access I could do it in 30 mins., but I aint Gumby. One note, I never did find the pin I heard was taped somewhere, I ordered it online (2 for $22).

 

[sjreib]

Thanks,
I suspect the access is even more severely limited on a C28. At 73 years of age and 6 feet tall, I'm not sure I could do it at all. Maybe a job for my smaller first mate.

 

[tlkenyon]

Some time back, a poster suggested that the factory was in support of placing a SS pin. Anybody know this first-hand?

TK

 

[NautiTug]

First time docking my new to me c28 yesterday and broke the bow shear pin. Confirmed the spare is there. But any other folks switch to a more forgiving stainless steel pin?

 

[Barerootsbob]

I’m no mechanical genius but it seems to me a SS shear pin is a bad idea. It’s designed to break before the plastic prop’s do. If the brass shear pin breaks it’s a small but dry problem to solve. If you break a plastic prop you will have a much bigger and more expensive repair in front of you. And if the boat is in the water somebody is going to have to dive to make the repair.

 

[NautiTug]

Makes sense. Thanks

 

[NautiTug]

Interesting to note though it now looks like Imtra only carries a stainless steel shear pin for our thrusters

https://www.imtra.com/3801e9da-13e6-40b ... tail.htm#A

 

[Cutwater28GG]

touch wood I havent broken a shear pin (im in that camp) but I dont understand how these break by changing direction of thruster. there is an electronic delay built into the units that forces the prop to be stopped before spinning it the other way?

I can only see that failures must be being caused by physical items in the water causing increased stress?

see page 2 safety section of the manual
https://side-power.com/produkt/19037/se30-tunnel-thruster-12v-ip/

 

[YukonRon]

Remember the old days when we had screw-in fuses in our house fuse panels? (Ya, I'm that old 😳 ) People would blow a fuse then just stick a penny in behind the fuse.
That's what I think of when I hear about "unbreakable shear pins". Kind of defeats the purpose.
You might get away with it if the thruster prop fouls and you pop a fuse before things break. But I too have broken a bow thruster shear pin from making quick direction changes, and I was glad to change the pin as a 1 hour (first time) dry fix rather then break something more serious.