Chapter 34—Fifth Wheels and Coupling Systems
1. Which of the following describes the role of a trailer upper coupler?
built into the truck frame and pivots fore and aft
built into the trailer frame and contains the kingpin
supports all of the trailer load
supports none of the trailer load
2. When a semi-trailer is properly coupled to a highway tractor, what trailer component transfers its weight to the tractor
chassis?
3. Which type of fifth wheel is most commonly used on linehaul highway tractors?
compensating fifth wheels
semi-oscillating fifth wheels
fully-oscillating fifth wheels
4. Which of the following applications would benefit from the use of a compensating fifth wheel?
B-train lead trailer with aluminum frame
A-train lead trailer with pintle hook
pick-up and delivery tractor
5. When a sliding fifth wheel is used on a highway tractor, which of the following positions would place the most weight
on the tractor front axle?
directly over the bogie centerline
slightly to the rear of the bogie centerline
6. When a sliding fifth wheel is used on a tractor, which position would most likely provide the driver with the most
comfortable ride?
over the bogie centerline
slightly behind of the bogie centerline
7. How often should a fifth wheel be serviced if the OEM recommendations are adhered to?
every 10,000 miles (16,000 km)
every 100,000 miles (160,000 km)
every 50,000 miles (80,000 km)
every 30,000 miles (48,000 km)