Peterbilt Medium Duty Truck Owner's Manual - Peterbilt Motors

DRIVING TIPS AND TECHNIQUES
STARTING AND OPERATING THE VEHICLE
Your Medium Duty vehicle may be equipped with either a
fixed or an air-controlled sliding fifth wheel. Either type
should self-lock when a trailer king pin trips the locking
dogs as the tractor is backed under a trailer.
Fifth Wheel Jaw Lock
To unlock the fifth wheel lock:
• Pull out on the lever (usually located on the left-hand
side of the fifth wheel) until it remains in an overcenter
position.
Hook–Up:
• After connecting your tractor to the trailer, always
inspect the jaws to be sure they have locked on the
kingpin before driving.
Fifth Wheel Slide Switch
FIFTH WHEEL
Air–Controlled Sliding Fifth Wheel
Vehicles having an air-controlled sliding fifth wheel have a
fifth wheel slider lock controlled by a switch on the accessory
switch panel. To operate this type of lock, move the
switch to the appropriate position. By placing the switch in
the UNLOCK position, you can slide the fifth wheel to various
positions to adjust weight distribution. There is a
guard on this switch to protect you against accidentally
activating or releasing the lock.
– 138 – Y53-6027 Medium Duty (R05/09)