7-2
7.3 Maintenance of Hull Unit
Lubrication
Grease the raise/lower screw shaft once a year. Also, grease
the raise/lower main shaft (upper part of the grease cotton re-
tainer) twice a year. These parts can accessed by removing
the raise/lower drive assembly cover.
Manual raise/lower of transducer with hand crank
Ship’s mains should be supplied to the hull unit to do this check.
Also be sure to press and hold down the brake-off switch while
manually raising/lowering the transducer. Failure to press the
switch may damage the raise/lower motor.
1. Turn off the breaker on the hull unit.
2. Remove the brake-off switch cover.
3. Set 19 mm socket wrench and turn it while pressing the
brake-off switch.
4. Check that the transducer can be raised/lowered smoothly
with a constant force from the upper to the lower limit posi-
tions. If not, centers of the main body flange and the retrac-
tion tank are not aligned. Adjust the hull unit mounting
position.
Brake-Off
switch
Raise
Lower
Breaker
Figure 7-1 Using the hand crank
