freightliner CL112 2015, Maintenance Manual

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31–00 Safety Precautions
Safety Precautions in this section apply to all
procedures within this group.
DANGER
When working on the vehicle, shut down the en-
gine, set the parking brake, and chock the tires.
Before working under the vehicle, always place
jack stands under the frame rails to ensure the
vehicle cannot drop. Failure to follow these steps
could result in serious personal injury or death.
31–01 Fifth Wheel Inspection
WARNING
All fifth wheel maintenance, adjustment, and re-
building must be done only by a qualified me-
chanic. Improper or incomplete procedures could
result in a possible disengagement of the trailer
from the tractor, which could result in personal
injury or property damage.
Parts are under spring compression. Wear safety
goggles while servicing the fifth wheel. Failure to
do so can result in personal injury, due to parts
ejecting with force.
Fontaine
1. Disconnect the tractor from the trailer. For in-
structions, see the
Columbia Driver’s Manual .
2. Thoroughly steam clean the fifth wheel.
3. Check for cracks in the fifth wheel assembly,
mounting brackets, and mounting parts.
4. Ensure that both bracket pins are in place and
secured by retainer pins and cotter pins. See
Fig. 1 .
5. For fifth wheels equipped with bracket liners,
rock the fifth wheel. If it does not rock freely, re-
move the top plate and inspect the bracket lin-
ers. Replace liners that are broken or less than
0.125 inch (3 mm) thick at the top of the liners.
For the liner replacement procedure, see the
Fontaine website,
www.fifthwheel.com .
6. Check the jaw and stationary jaw for mushroom-
ing, and check that the serrations at the jaw and
wedge are in good condition.
7. Test the secondary safety lock latch for ease of
operation.
8. Check for loose nuts or bolts on the fifth wheel
and the mounting. Set a torque wrench to the
maximum torque value for the bolt being
checked, and confirm that the torque is to speci-
fication. Do not loosen the bolt to check the
torque. See
Group 00 for bolt torque specifica-
tions.
9. Check all springs to see if they are securely fas-
tened, and are not deformed.
WARNING
Do not disassemble the fifth wheel to inspect the
springs. The springs are under extreme pressure,
and could cause serious injury.
10. Check the wedge adjustment.
10.1 Close the fifth wheel on a standard 2-inch
(50-mm) kingpin or similar 2-inch (50-mm)
diameter shaft so that it locks.
10.2 Push on the wedge stop rod with hand
pressure. It should move in 1/4 inch (6
mm) and spring back out on release.
If the free travel is not 1/4 inch (6 mm),
adjust the distance to 1/4 inch (6 mm) by
turning the wedge stop rod, on the right
side of the top plate, clockwise to reduce
the gap and counter-clockwise to in-
crease it.
11. Replace cracked, worn, or damaged parts with
new parts. Replace all loose mounting bolts with
5/8–11 SAE grade 8 bolts, grade C locknuts, and
hardened washers.
Do not re-use bolts, nuts,
and washers on fifth wheel mountings.
12. After inspecting the fifth wheel, lubricate all mov-
ing parts with a chassis or multipurpose grease.
Apply a generous coating of grease to the top
plate to fill the grooves, or depressions, on the
top plate. See
MOP 31–02 for lubrication instruc-
tions.
Frame and Frame Components
31
Columbia Maintenance Manual, July 2017
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