Changing bow thruster shear pin

mcanderson

mcanderson

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So day four with our new boat and it sounds like the bow thruster shear pin has gone. I was positioning the bow to enter our berth when it stopped providing any thrust and just making a whirring noise. I tried to film the bowthruster with my phone in a water proof cover attached to my boat hook, but not joy. Just to see if the prop was still intact.

I had gone from one direction to the other probably too quickly hence the pin working as advertised.

Here is the question - do I need to book a lift or can this be done in the water armed with snorkel and fins in shallow enough calm water so when I drop something I can get it back? The model is a side power SE60/185 S.
 
You shouldn't even need to get wet! On most of them the pin that shears is under the motor in your forward locker. Typically undo 4 bolts, lift off a heavy motor and swap the pin. There usually is also a pin behind the prop but my understanding is that it rarely goes there.
 
Normally under the motor as it attaches to the gearbox ,inside .
If so removal of the motor and look on top of the gearbox ,the bit inside the boat .

If it hasn't sheared then it's a new gearbox ,that's ( assuming the part is available ) is you guessed it another €1000 + lift (s)

Gear boxes go
1- anode not changed -so corrodes let's in sea water
2- oil runs dry or not topped up --- so not enough pressure @ the shaft seal and seawater seeps in as opposed to oil out ,inevitably -corrosion and eventually a "whirring "noise.

Preventive measures
1- new anode every year -can be a pita -hence not done
2- ck and top up the oil reservoir as and when .

Good luck with it
 
Thanks for the replies, but my thruster parts diagram shows the drive pin behind the propeller so dry access can only be done lifted out. The anode was changed at the prepurchase maintenance.

So snorkel or not is my dilemma. My wife is very confident in my handling so far she thinks leave it until next scheduled maintenance period. I'm not sure I share her confidence and may have just been lucky so far.
 
She,s right ------ as Allways for happy boating :)
I had a season without On a Sunseeker .
Sharpens up throttle adjustment / windage / appreciation of "slide " .

The only thing until next haul out give her the job of handling the roving fender
 
Would tend to say leave til next lift/service. I take the prop off every year for antifouling and change anode. Usually ok, but you have a nut, washer, anode, washer and hex head threaded bolt to remove under water while trying to keep the prop in a fixed position with a piece of wood wedged against the thruster leg. I wouldn't fancy it, but it is doable (plenty of bits to drop/loose).

Mike
 
Mike, I have been through the exploded diagram in the manual and agree it's a more than one breath of air job! I will see what is in the art of the possible and if I can get a quick lift and hold for an hour to do it then it will be worthwhile. We are not back for three weeks so plenty of planning time.
 
Page 8 fig 2 you can just see the groove that the motor drive pin locates into.

They do not show the motor shaft and pin, but mention it in the text, in point 3.So I guess that it must be there.
 
Goto page 19
"drive pin " on the prop #2 under water an shear pin inside # 20 are two seperate things .
I refer you back to my post 3

It would be be a Waco Craco design getting wet -- it isn,t

Lift off the motor as suggested
 
See page 17 - Troubleshooting
If the drive pin on the motor shaft is broken Remove motor and replace the drive pin
 
I'm guessing there are 2 possible pins in the system which might break, the drive pin on the prop shaft and a shear pin on the drive shaft from the motor. I would bet that it is the shear pin which has failed and that should be accessible by removing the motor from the inside. Probably worth calling Osmotech in the UK (Side Power dealers) to ask them
 
Btw welcome to motorboating. You will find dealing with regular breakdowns which occur at inopportune moments infuriatingly normal:D
 
Portofino said:
Goto page 19
"drive pin " on the prop #2 under water an shear pin inside # 20 are two seperate things .
I refer you back to my post 3

It would be be a Waco Craco design getting wet -- it isn,t

Lift off the motor as suggested
Click to expand...

I offer a full and unremitting apology! I hope it is this pin. I will order two of each and see how I get on.
 
Deleted User said:
I'm guessing there are 2 possible pins in the system which might break, the drive pin on the prop shaft and a shear pin on the drive shaft from the motor. I would bet that it is the shear pin which has failed and that should be accessible by removing the motor from the inside. Probably worth calling Osmotech in the UK (Side Power dealers) to ask them
Click to expand...

Mike, you and Portofino look like being right. I rang Osmotech and spoke to Mark (who was brilliant) and he has said that it most likely to be the shear pin under the motor. Two ordered and on the way. I will find out in three weeks when I get back down to BSM.
 
mcanderson said:
Mike, you and Portofino look like being right. I rang Osmotech and spoke to Mark (who was brilliant) and he has said that it most likely to be the shear pin under the motor. Two ordered and on the way. I will find out in three weeks when I get back down to BSM.
Click to expand...

The same thing happened to me in Majorca a few years ago albeit with a Vetus bow thruster and the failed shear pin was under the motor. If you think about it, it would be stupid to have the primary failure component in a position which could not be accessed from inside the boat although of course it is still possible that your prop drive pin has failed so might be wise to get a spare one of those too
 
You also needto understand why your pin sheared. Check for flotsam fouling the thruster propellers, and if poss also look whether there are score marks around one part of the circumference on the grp tunnel. If so, the thruster may need re-alignment and the pin may shear again until it's done.
 
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