I have successfully used the AMEL supplied bow thruster repair tool six times
(twice on my SM #336 and four times helping fellow owners) and use the
1) Lower the bow thruster until it is about 10-15 cm (4-6 in) above the fully
2) Securely fasten a hose clamp around the bow thruster shaft so it cannot
move further down.
3) If fitted, remove the collar from the base of the motor. Then remove the
four allen screws that secure the shaft to the motor.
4) Raise the bow thruster motor to the fully up position. This will leave the
bow thruster shaft down and disconnected from the motor, with room to install
5) Fit the AMEL tool into the top of the bow thruster shaft with the hole for
the line facing aft (towards you - this is to help correctly orient the bow
thruster when you reinstall it.) and carefully secure it using the two set
6) Clean all grease from the top of the bow thruster shaft and the tool.
Carefully apply plastic electrical tape to the joint between the tool and shaft,
being sure to also cover the screw holes.
7) Secure the bitter end of the line from the tool, loosen the hose clamp and
lower the bow thruster assembly until it can be retieved from on deck or a
dingy using a boat hook.
8) Replace the prop (if you need instructions let me know). You may also wish
to replace the bow thruster gear oil at this time (optional). If so, remove
the tape and tool. Invert the unit to drain the oil, add new oil, replace the
tool and retape.
9) Carefully lower the unit into the water and retrieve it using the line
fixed to the tool. Ensure that the hole in the tool is facing you to properly
orient the unit. Secure the shaft with the hose clamp in about the same positon
as before. Remove the tape and tool.
10) Lower the bow thruster motor about 10-15 cm (4-6 inches). Raise the
shaft manually and mate it with the motor. Sometimes it is a bit difficult to get
the spline from the motor to mate with the drive shaft. Just keep trying and
it will suddenly come together. Secure the asssembly with the four allen screws
and replace the security collar. Remove the hose clamp.
11) Test the unit by fully raising and lowering it several times.
12) Have a beer or two!
This all may sound a bit daunting, but it really is straight forward and
simple if you take your time and think ahead. It should take about 30 minutes.
S/V MALAIKA II