Fifth Wheel Lubrication; Fifth Wheel Coupling - freightliner M2 Plus 2023 Manual

Fifth Wheels and Trailer Couplings

Fifth Wheel Lubrication

WARNING
A standard fifth wheel plate must be kept
lubricated to prevent binding between the tractor
and trailer. A binding fifth wheel could cause
erratic steering and loss of vehicle control,
possibly resulting in personal injury or death.
The standard fifth wheel plate must be kept well
lubricated with chassis grease to prevent friction and
binding between the tractor fifth wheel plate and the
trailer.
For lubrication instructions, see Group 31 of the M2
Plus Maintenance Manual.
For a low-lube fifth wheel plate, inspect the condition
of the low-lube pads. There should be no damaged
or missing pieces. Slight puckering at the outside
edges is normal.
For no-lube fifth wheel plates, inspect the condition
of the no-lube pads. If any of the following conditions
are present, replace the lube plates.
•
Plates severely chipped, cracked, gouged, or
bent.
•
More than 20% of the lube plate coating
missing from one or both plates due to normal
wear.
•
A straight edge laid across the lube plate
contacts parts of the surrounding fifth wheel as
shown Fig. 17.1.

Fifth Wheel Coupling

WARNING
Do not use any fifth wheel that fails to operate
properly. Doing so may cause loss of vehicle
control, possibly resulting in severe personal
injury or death.
Fifth wheel coupling is activated with the lock control
handle located on either the right or left side of the
fifth wheel. Coupling has successfully occurred when
the kingpin is in the fifth wheel jaws and the control
handle has moved to the locked position.
Due to the number of options available, your vehicle
may be equipped with a fifth wheel not described in
this manual. In this situation, please reference the
vendor literature on the fifth wheel installed.
17.1
04/22/2020
A. Contact with the surrounding fifth-wheel when
placing a straight edge across the lube place
indicates too much wear.
Fig. 17.1, No-Lube Plate Wear Inspection
NOTICE
Some fifth wheels may be mounted on sliding
rails. Before attempting to couple a trailer to a
sliding fifth wheel, the slide feature must be
locked to prevent the top plate from sliding
rapidly forward or rearward, causing damage to
the fifth wheel or kingpin.
Trailer Auxiliary Switch
The trailer auxiliary switch energizes an optional
circuit that allows the trailer electrical system to draw
power.
Press the top of the switch to activate the trailer
auxiliary function. Press the bottom of the switch to
turn trailer auxiliary function off. See
Fontaine Fifth Wheel Coupling
1. Chock the front and rear of the trailer tires to
prevent the trailer from moving.
2. If equipped with a standard fifth wheel, check
the surface of the fifth wheel for a liberal coating
of grease.
If equipped with a no- or low-lube fifth wheel,
inspect the conditions of the pads.
A
f311258
Fig. 17.2.