Forward thruster shear pin at 50 hours

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Pfisher

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Jul 8, 2015
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26
Fluid Motion Model
C-24 C
Non-Fluid Motion Model
Cutwater 28
Vessel Name
Mary Yulan
I am a relative newbie with my cut water 28 as my first new boat, purchased last Spring. I just got it back in the water and yesterday went out for a short " test cruise". :shock: The thrusters helped me out of the slip, but the forward thruster was non functional trying to get back into it ( the thruster motor spun without apparent load, so I guess I lost the forward shear pin.) I thought I handled the thrusters with special care, so I am distressed to have this problem 50 hours into my boating experience! So, do I have to haul her out again to fix this, can a diver handle this, etc? Should I keep a spare shear pin on board for repeat adventures ? Finally, did I do something wrong or are these pins known to shear just from use/ malalignment/debris/wave action?

Thanks for any guidance you guys can offer. I hope our family is not out of action for too long!
 
I always keep extra shear pins and a couple of extra retaining clips onboard.

I lost my bow thruster pin last season at about 40 hours, but it's not the hours on the shear pin - it's the load. They are sacrificial elements and are supposed to give way to avoid burning out the motor.

I am not familiar with the Cutwater access to the bow thruster, but I was able to replace mine while in the water - took about 30 minutes as a first-timer. There are multiple forum threads on TugNuts on how to do it yourself - use the search bar at top and good luck.

Feel free to PM me if you have questions.

Good luck,

John
 
I've replaced my bow shear pin with the boat in the water and I'm guessing a Cutwater would be the same. On our R27 there was a spare shear pin attached to the side of the thruster, you might check yours. As John pointed out it's a good idea to carry extra anyway. After getting the thruster exposed the most difficult thing is lifting the motor away and up out of the compartment to access the shear pin replacement.

Jim F
 
I changed mine today because it broke at about 90 hours on the engine. In my case removing the motor to reach the shear pin was no problem at all, but to remove the remaining parts of the broken one and to insert the new one was A PAIN IN THE ASS.

You should have a spare one attached to the thruster cover. If you give me your email I can forward you the instructions to do it yourself.


Sent from my iPhone using Tapatalk
 
They should have done it using a Ranger stern thruster. It would have been a much longer video. :lol:
 
Kinda wondering if the stern thruster was installed on the starboard side would it be easier to service or are there other components in the way ( power steering, sounder etc)
 
what is the snap ring pliers like tool? where do I get one of those!?
 
Cutwater28GG":2j7antjw said:
what is the snap ring pliers like tool? where do I get one of those!?
Click to expand...

They are a specialized type of plier/s like this
416wMVt6XrL._SX300_.jpg


Available at most hardware stores.

I have some cheap ones from Harbor Freight which are perfectly fine for the limited use they see.

They come is either 'straight' or curved prongs. And the tips come in 'sizes' so ensure you carry the ones to fit your thruster.

/dave
 
Hi! Thanks to all of your helpful advice, I am back in service.
However, I still am worried, because in my inexperience, I may have screwed up the "fix" a bit.
1. Try as I might, I could not get one of the broken fragments of pin out of the shaft holes. I saw a second set of identical looking holes, set at right angles to it, so I wound up using those ( and, of course, if this happens again, I have NO THIRD set of holes to use!) Should I pull this off again, and keep working with the pin punch? I guess I was worried that I was going to damage the axle itself If I was too rough? Or, can I drill out the brass pin fragment safely?

2. When I tapped the new pin into place, the soft brass end flattened a bit, so it did not seat completely flush with the axle hole. In fact, it slightly interferes with the retaining ring, since it protrudes a small amount just at the level of the ring. I bought some new pins and retaining clips from IMTRA; should I try again?

3. I thought it would be wise to check the stern thruster on my Cutwater 28, to check the appearance of its pin. How do I get access to it? I think that the thruster unit should be just port of the middline on my transom, but I can't see it and can't get even close to it, with installed tanks, and macerators, etc all seemingly in the way. Should I remove the rear "flippable" transom seat and storage?

4. I have images of these "repairs"; how can I upload them to this BB?
 
Shear pins are old school and could easily be replaced with electronics that monitor rpm current and temperature. In fact if the shear pin breaks the motor will spin at a high rate as if the thruster is not in water, something that is not recommended to do.

Electronic control of the motor would make sure in rush currents are within safe limits, stall currents are avoided and alert the op of problems. Considering the price and shear pin location of these little puppies that should all be part of it

Some might say we don't need another electronic dependency. Well those are the ones that never replaced a shear pin .)
 
My bow thruster has the same problem at 120 engine hours. IT spins as if in neutral. If it is the shear pins, why are the shear pins failing at such low hours. If it is a fail safe to protect the motor, then what am I doing wrong? Guess I am missing something? Also, where do you buy extra shear pins?
thanks for your help
Joe "Flying Turtle" C-28
 
There should be a spare shear pin attached to the thruster, at least there is one on mine. Of course ranger tugs is your to go source always. But shear pins are surely to be gotten elsewhere.
 
The thrusters used on the Ranger and Cutwaters share a common design issue: The thruster shear pin is in a difficult to access location and is under strength for the task.

There are three failure points I've "discovered" the hard way on my R-25.

1. The Shear pin is the hardest to correct and fails from time to time for no real reason If you switch from port to starboard thrust without pausing, the shear pin snaps. It is hard to replace.

2. The second "fuse" is the propeller and drive leg. The propeller is very easy to replace out of the water and should have an integrated shear pin to eliminate the need for the hard to access pin.

3. The third is the fuse - it would be trivial to replace once the non-standard Sidepower fuse block is replaced with a "standard" size block. The necessary fuses then become about $2 each and are easily obtained from Amazon.

Finally, Imtra, the local Side Power supplier in Florida, and Ranger all seem aware that there is a replacement shear pin you can fabricate (the local dealer sold two for $8) that is made of stainless steel and removes problem 1. You are still left with the fuse and propeller for protection.

I suggest you get two unbreakable un-shear pins so you have to replace each thruster pin only once more.
 
Flying Turtle asked why a shear pin would go at such low hours? The hours are really not the issue it is how the thruster is operated, as pointed out in the post below. Additionally it depends whats in your boats surrounding water when you use the thruster. A small piece of wood, plastic or any other debris can work its way into the thruster tunnel to cause an obstruction and it does not now how many hours are on the boat. You could have owned your boat for 3 years or 3 days and a shear pin could go out, depending on conditions you may not have control over. Hope this helps,

Jim F
 
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