Sleipner Side-Power bow thruster

[alancollins]

My bow thruster has begun making an unusual noise. Occasionally it gives a high pitched whine as though the motor is running, but without the propellor throwing much, if any, water.
It is as if a clutch is slipping, although I am not aware that a clutch mechanism is part of the design. It happens infrequently and usually runs perfectly, but makes me wonder if something is about to fail. Has anyone else experienced something similar?

 

[spannerman]

There is not clutch just a break pin which if broken won't transmit any drive from the motor. I'd take off the motor either 2 or 4 bolts and inspect the coupling and rotate the input shaft to the gearbox to see f it feels notchy, damaged teeth?

 

[Momac]

I had a similar issue - not the same brand of thruster.
Mine had a shear pin which is accessible inside the boat by removing the motor - the shear pin was intact.
When the boat was lifted out found there was another shear pin . That shear pin also was also intact , but the propeller had broken.

 

[Firefly625]

Before you get too worried about a mechanical fault it may just be if air is getting in, so bow too high and pulling air into the tube, effect will be dramatic change in pitch and zero thrust. I get this on our stern thruster if our water tank is empty (which is under the cockpit floor!)

 

[alancollins]

Thanks all. Firefly, you may have a point. This only happens when I am about to moor and the crew are in the cockpit, waiting to step ashore. I will try a diffferent procedure before resorting to dismantling the thruster.