freightliner M2 Plus 2023 Manual page 210

Fifth Wheels and Trailer Couplings
wheel inspected and adjusted by a certified
technician.
Jost Fifth Wheel Coupling
1. Chock the front and rear of the trailer tires to
prevent the trailer from moving.
2. Tilt the fifth wheel ramps down.
3.
Unlock the fifth wheel jaws.
Lift the release handle up into the wide slot and
then pull the release handle out while moving it
forward as shown in
into the open position on the notch provided.
B
C
A
11/01/2021
A. Lift the release handle up into the wide slot.
B. Pull the handle out.
C. While pulling the handle out, move it forward.
Fig. 17.17, Unlocking the Jost Fifth Wheel
4. Back the vehicle close to the trailer, centering the
kingpin on the fifth wheel throat as shown in
Fig. 17.4.
NOTICE
Attempting to couple at the wrong height may
cause improper coupling, which could result in
damage to the fifth wheel or kingpin.
5.
Adjust the trailer height (if required).
For a standard fifth wheel plate, the trailer
should contact the fifth wheel the top of the
approach ramps or approximately 4 to 6 inches
(10 to 20 cm) behind the pivot point as shown in
Fig. 17.5.
For a low-lube fifth wheel plate, the trailer
should contact the fifth wheel at the pivot point
17.7
Fig. 17.17. Lock the handle
f311395
and the fifth wheel must slide freely under the
trailer as shown in Fig. 17.6.
6.
Back the tractor slowly toward the trailer.
On a standard fifth wheel, the fifth wheel must
lift the trailer.
On a no- or low-lube fifth wheel, do not lift the
trailer. Lifting the trailer with a no- or low-lube
fifth wheel may damage the fifth wheel plate.
After lifting or sliding under the trailer, stop. This
is to prevent hitting the kingpin too hard. Then
resume backing up slowly until the fifth wheel
locks.
WARNING
A visual inspection is required by law.
Some improper couplings can pass a pull test.
Sound is not reliable.
Get out of the cab and look.
Incorrect coupling could cause the trailer to
disconnect, possibly resulting in serious
personal injury or death.
7. Apply the tractor parking brake, then perform a
physical check for positive kingpin lockup.
Depending on the fifth wheel model, the handle
should be fully retracted with the handle inside
the narrow slot as shown in
release handle should abut the casting as shown
in Fig. 17.19.
There should be no gap between the trailer and
the fifth wheel.
A
11/01/2021
A. Verify the handle is inside the narrow slot.
Fig. 17.18, Locked Jost Fifth Wheel
Fig. 17.18 or the
f311396