Now thruster shear pins breaking

Nov 19, 2009
289
Hunter 45CC Ft Pierce and Abaco Bahamas
Do any of you that have bow thrusters experience motor shear pins breaking? If so how often?
 
Nov 19, 2009
289
Hunter 45CC Ft Pierce and Abaco Bahamas
I'm waiting for someone to say, "any time you get debris in the tunnel", but I'm looking to find out if anyone has issues of the shear pins breaking with no debris injested, just from age or wear
 
Oct 1, 2007
1,865
Boston Whaler Super Sport Pt. Judith
Yup. Mine sheared last spring after 8 years. No reason that I could determine. Just wear and tear I guess. If it is the same unit as I have there are 2 shear pins. One inboard and one outboard. Clever design as the inboard is smaller in diameter and should fail first. You should also find 2 shear pins attached to the inboard motor. Mine is a Side Power.
 
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Nov 19, 2009
289
Hunter 45CC Ft Pierce and Abaco Bahamas
Yup. Mine sheared last spring after 8 years. No reason that I could determine. Just wear and tear I guess. If it is the same unit as I have there are 2 shear pins. One inboard and one outboard. Clever design as the inboard is smaller in diameter and should fail first. You should also find 2 shear pins attached to the inboard motor. Mine is a Side Power.
Yep mine is a Side Power SE60. I just bought the boat from someone that used it very lightly and he said the motor pin broke once or twice on him and it just broke on me after using it only maybe 10 times very short bursts. I went ahead and ordered a few pins for when I go to change it because he may have used the ones taped to the motor. It doesn't look like a difficult job to replace it, as seen on a video. I guess I should check if there is any debris in the tunnel before I try to use it after I replace the pin. I assume once the motor is off I can spin the shaft that goes to the prop and just see if it's at least free also.
 

capta

.
Jun 4, 2009
4,905
Pearson 530 Admiralty Bay, Bequia SVG
I would check to make sure some debris hasn't bent the prop and its now hitting the side of the tunnel.
 
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Nov 19, 2009
289
Hunter 45CC Ft Pierce and Abaco Bahamas
Absolutely. It it did anything it likely broke it. It's plastic
 
Sep 10, 2012
222
Hunter 450 Gulfport, Florida
Hey Rick. twice in one week you have tossed me valuable info! My thruster made a crunching sound one day and ceased to thrust. I had recently replaced the control board as well as the controller as they were both blown. I pulled the motor for the thruster and the shear pins were good, I rotated the drive and it turned smooth as silk so I thought the prop had stripped where it mounts to the shaft, but you say that there is a second shear pin externally? Does it sit in a recess in the prop? I'm guessing they don't mount spares nearby! It is also a sidepower.
 
Oct 1, 2007
1,865
Boston Whaler Super Sport Pt. Judith
Hey Rick. twice in one week you have tossed me valuable info! My thruster made a crunching sound one day and ceased to thrust. I had recently replaced the control board as well as the controller as they were both blown. I pulled the motor for the thruster and the shear pins were good, I rotated the drive and it turned smooth as silk so I thought the prop had stripped where it mounts to the shaft, but you say that there is a second shear pin externally? Does it sit in a recess in the prop? I'm guessing they don't mount spares nearby! It is also a sidepower.
Can you hear the motor spin? I have never looked at the outboard pin but it must fit in as a shear pin on an outboard prop, i.e. in a prop recess.
 
Dec 29, 2008
805
Treworgy 65' LOA Custom Steel Pilothouse Staysail Ketch St. Croix, Virgin Islands
I would check to make sure some debris hasn't bent the prop and its now hitting the side of the tunnel.
That would be my concern, too. Either that, or you keep sucking sea turtles in there causing the pins to shear but leaving no evidence... Which also make me ask, do you see any evidence of the props being rubbed clean by a foreign object?
 
Nov 19, 2009
289
Hunter 45CC Ft Pierce and Abaco Bahamas
That would be my concern, too. Either that, or you keep sucking sea turtles in there causing the pins to shear but leaving no evidence... Which also make me ask, do you see any evidence of the props being rubbed clean by a foreign object?
Haven't checked the prop yet but will after I change the shear pin
 
Sep 10, 2012
222
Hunter 450 Gulfport, Florida
Can you hear the motor spin? I have never looked at the outboard pin but it must fit in as a shear pin on an outboard prop, i.e. in a prop recess.
Yes the motor spins beautifully although no load, when I turn the the drive with the motor removed it turns super silky so I assumed the gearing was either completely stripped out (never seen anything strip that completely) or the shaft connection to the prop was stripped, rotating it by hand would not load the prop enough to feel it slipping, a broken shear pin is now the other option.
Will be verifying the shaft diameter this weekend for the prop.
 
Last edited:
Nov 19, 2009
289
Hunter 45CC Ft Pierce and Abaco Bahamas
Dehler

My money would be on the shear pin behind the prop is broken. When my boat was hauled this winter I removed the thruster prop to paint it and the tunnel. There is a shear pin behind the prop. The shear pins should break long before the gears would strip if the tunnel invested something it didn't like.
I just changed the motor shear pin. Broke in two. Pic attached
 

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