freightliner M2 Plus 2023 Manual page 206

Fifth Wheels and Trailer Couplings
08/24/2021
A. Line up the fifth wheel throat with the trailer kingpin.
1. Kingpin
Fig. 17.4, Positioning the Tractor
D
C
04/28/2017
A. The fifth wheel must lift the trailer.
B. Adjust the trailer height if necessary.
C. Tilt the ramps down.
D. Trailer should contact fifth wheel 4-6 inches behind
pivot point.
Fig. 17.5, Trailer Connection Point, Standard Fifth
B
04/28/2017
A. Adjust trailer height as needed.
B. Verify pivot point allows fifth wheel to slide under
trailer.
Fig. 17.6, Trailer Connection Point for No- and Low-
Lube Fifth Wheels
17.3
A
1
A
B
Wheel
A
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.
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10.
Perform a coupling inspection.
10.1 Verify there is no gap between the bottom
of the trailer and the fifth wheel as shown
in
10.2 Make sure the jaw and wedge of the fifth
wheel are locked in place behind the
kingpin as shown in
A
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04/28/2017
A. Check that there is no gap between the trailer and
fifth wheel.
B. Verify the kingpin is locked in the fifth wheel jaws.
Fig. 17.7, Coupling Inspection View
10.3 Check that the lock control handle is fully
retracted as shown in
between the back of the pull handle and
the skirt of the fifth wheel should be less
than one inch as shown in
Incorrect fifth wheel locking could cause the
trailer to disconnect, possibly resulting in serious
personal injury or death.
11. Release the tractor parking brakes.
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Test for kingpin lockup by slowly inching the
tractor forward, pulling on the trailer against the
chocks.
12.
After lockup is completed and verified, connect
the tractor-to-trailer air system lines and the
electrical cable to the trailer. Take care to prevent
WARNING
Fig. 17.7.
Fig. 17.7.
B
Fig.
WARNING
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17.3; the gap
Fig. 17.8.