For the AK 7 AK 10/2 AK 252:
Articulation:
Maintain articulation angle at ±25°( vertically (Fig. 1)
Maintain articulation angle at ±20° horizontally (Fig.1)
CAUTION: If the articulation angle is exceeded,
components will be overloaded. The function is no
longer ensured!
Coupling Up:
Push the safety lever (Fig. 4/1) up with the index
finger and lift the handle up and forwards.
Put the opened coupling onto the towball with the
handle pulled up and in addition press down by hand.
The coupling will close by applying a light pressure.
Press the handle down by hand until the catch (Fig.
4/3) snaps out.
The coupling head is correctly engaged when the
green edge of the visual indicator is visible (Fig. 4/2).
CAUTION: It is most important to check that the
coupling head is properly engaged on the towball
each time.
Uncoupling
Lift coupling handle fully and remove the coupling
head from the towball of the towing vehicle. Where
there are higher nose loads, coupling and uncoupling
can be made easier by use of the jockey wheel.
Wear indicator:
If the handle reaches back to the cutaway portion of
the housing when the coupling head is engaged (Fig
5) there will be play between the towball and the
coupling head!
Automatic readjustment is no longer possible and the
assembly will require inspection.
CAUTION:
Under these circumstances the coupling head can
become detached from the coupling ball and the
trailer break away from the towing vehicle!
The coupling head and towball must therefore be
checked IMMEDIATELY before future use. Any faulty
parts must be changed IMMEDIATELY.
All maintenance work is to be carried out by specialist
workshops authorised by AL-KO (AL-KO have a
network of Service Centres in the UK & throughout
Europe)
Fault
Coupling does not engage when
placed on ball
Trailer cannot be uncoupled
Too much play in the coupling
danger of trailer becoming
unhitched
Elimination
Change ball.
Clean and grease coupling,
replace as necessary.
Align trailer and car and
uncouple.
Grease/lubricate coupling
mechanism.
Have coupling changed.
Have towball changed.
Servicing and Cleaning
Lubricating points (Fig. 6)
Clean towball coupling.
Lightly grease, or oil ball socket, joints and bearing
points as appropriate
General purpose grease to DIN 51825 KTA 3K.
Servicing and care of hot dip galvanized vehicle parts:
The formation of white rust is only a surface coating
and has no adverse effect on the anti-corrosion
properties of galvanising. In order to minimise the
potential for the formation of white rust the following
precautions should be taken:
• Ensure there is adequate air circulation when
storing the hot dip-galvanized parts.
• After winter journeys it is recommended that
surfaces are washed with clear water.
Troubleshooting
Cause
Ball diameter greater than
50 mm.
Inner parts of the coupling are
dirty or are not functioning
correctly.
Ball deformed.
Coupling worn out.
Articulation angle exceeded.
Rivet bent.
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