4
Fault
Cause
2 Troubleshooting
The fifth wheel
coupling will
not unlock.
1.
Relieve the strain on the fifth wheel coupling locking
mechanism.
2.
The fifth wheel coupling can be opened by force as
follows:
Undo the lock nut on adjusting screw SK 8301-301 and
tighten the screw (max. 30 Nm) to prestress the locking
mechanism. Swing the handle forwards to disengage the
lock. Have a second person on the opposite side of
the fifth
wheel coupling with a crow bar (20 mm in diameter and
approx. 600 mm long) hit the tip of the locking bar
SK 8101-
201 through the hole provided for this purpose in the rib so
as to release the bar. Then rectify the poor maintenance
problem, check the wear parts for signs of damage and
repair them if necessary and reset the locking mechanism.
Fifth wheel cou-
pling does not
stay in its pre-
set position.
Fifth wheel cou-
pling will not
lock.
1.King pin position
is
too high.
2.Skid plate uneven,therefore
the king pin is positioned
incorrectly.
3.King pin is not true to size or
is damaged.
4.Lock jaw
deformed.
5.Poor maintenance.
6.Double tension spring
defective.
7.Lever and/or handle
is
bent.
1.The skid plate should be at the same level or max.
50 mm
lower than the fifth wheel coupling.
2.Change the skid plate. Permitted flatness tolerance
max.
2 mm.
3.Replace the kingpin.
4.ReplacelockjawSK8101-201
5.Open the mechanism and greaseit.
6.Replace double tension springSK8301-210.
7.Replace or straighten the lever SK 8301-214 and
handle
SK8301-213.
Solution
1.The semi-trailer unit is not flat
or is pulling on the coupling.
2.Poor maintenance, damageto
the lock jaw or locking bar or
incorrect lock jaw
adjustment.
1.ReplacelockjawSK8101-201
2.ReplacespringSK2106-01.
3.Open the mechanism.
1.Lock jaw
deformed.
2.Spring defective.
3.Poormaintenance.
