Volvo D4, Operator'S Manual

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87
Drive
Your drive is protected against galvanic corrosion. This protection consists of two-three layers of paint, sacrificial
anodes and ground braids. The ground braids maintain a connection between the different components of the
drive. A broken connection can result in the rapid corrosion of an individual component even though the protec-
tion is otherwise effective. Check ground braids every year. Faulty electrical installation can also cause the break
down of the galvanic protection. Damage due to electrolytic corrosion occurs rapidly and is often extensive. For
further information see the chapter: “Electrical system”.
IMPORTANT! Always repair damage to paintwork immediately. Improperly applied paint or the wrong type
of paint on the keel can put the corrosion protection system out of action. For further information on paint-
ing see the chapter: Laying up and launching
The drive is equipped with a cone clutch for shifting using a control cable with either mechanical operation or an
electric actuator and electronic operation.
Corrosion protection. Checking/Changing
Check the sacrificial anodes regularly. Change with
new anodes when approximately 1/3 of the anode
has been eroded. Tighten the new anode so that
there is a good electrical contact.
Where boats are kept laid up on land when not in use
there is a lower level of galvanic corrosion protection
due to the oxidation on the sacrificial anodes. Even
a new anode can be oxidized on the surface. Before
launching the sacrificial anodes must be cleaned/
ground using an emery cloth.
IMPORTANT ! Clean with sandpaper. Use no
steel tools (e.g. wire brush) as this will impair
electrical protection.
Your drive is equipped with sacrificial anodes of
zinc as standard, intended for use with salt water.
On drives used mainly in freshwater the sacrificial
anodes should be of magnesium.
IMPORTANT ! Use protective anodes as follows:
Zinc for use in salt water
Magnesium for use in fresh water
Aluminium if the boat is used primarily in salt water
and occasionally in fresh water.
Changing corrosion protection
All anodes are secured with screws. Undo the screws
holding the anode. Clean the contact surface and fit
the new anode.