Deck 34: Fifth Wheels and Coupling Systems

Question 1

Which of the following lubricants should be used to grease a fifth wheel?

A) water-resistant lithium-base grease
B) 80/90 gear lube
C) any type of axle grease
D) 85/140 axle lube

Answer 1

A

Question 2

If a rigid 5th wheel is used on a tractor,to which of the following applications would it likely be coupled to?

A) high rigidity tanker monocoque
B) frameless dump with oscillating bolster plate
C) C-train lead trailer
D) low bed gooseneck

Answer 2

B

Question 3

Which type of fifth wheel is most commonly used on linehaul highway tractors?

A) compensating fifth wheels
B) semi-oscillating fifth wheels
C) fully-oscillating fifth wheels
D) elevating fifth wheels

Answer 3

B

Question 4

Which type of 5th wheel is designed to articulate on all planes?

A) semi-oscillating
B) fully-oscillating
C) compensating
D) sliding

Question 5

How often should a fifth wheel be serviced if the OEM recommendations are adhered to?

A) every 10,000 miles (16,000 km)
B) every 100,000 miles (160,000 km)
C) every 50,000 miles (80,000 km)
D) every 30,000 miles (48,000 km)

Question 6

When a semi-trailer is properly coupled to a highway tractor,what trailer component transfers its weight to the tractor chassis?

A) kingpin
B) landing gear
C) bolster plate
D) fifth wheel plate

Question 7

Which of the following types of fifth wheels is capable of altering the weight over the tractor rear axles?

A) semi-oscillating
B) sliding
C) compensating
D) no-slack,semi-oscillating

Question 8

Which of the following applications would be most likely to use a fully oscillating 5th wheel?

A) B-train lead
B) high center of gravity hopper
C) low center of gravity goose-neck
D) C-train lead

Question 9

Which of the following is the correct method of adjusting a Holland B-lock 5th wheel?

A) lock closed,rotate rubber bushing by hand.If tight,turn adjusting nut CCW until snug
B) lock closed,rotate rubber bushing by hand.If tight,turn adjusting nut CW until snug
C) jaws open,rotate rubber bushing by hand.If loose,turn adjusting nut CCW until snug

Question 10

What of the following would be more likely to cause an upper coupler bolster plate to become distorted into ripples?

A) improper welding procedure during assembly
B) trailer consistently overloaded
C) occasional on/off-road use
D) lack of lubrication

Question 11

When a sliding fifth wheel is used on a tractor,which position would most likely provide the driver with the most comfortable ride?

A) full travel forward
B) over the bogie centerline
C) slightly behind of the bogie centerline
D) full travel rearward

Question 12

Technician A says that the position a sliding 5th wheel is located on a tractor affects the tractor bridge formula.Technician B says that the position a sliding 5th wheel is located on a tractor affects the trailer bridge formula.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 13

When a tractor sliding 5th wheel is inappropriately placed,which of the following can result?

A) weight-over-axle infractions
B) unbalanced bridge formula
C) uncomfortable ride
D) all of the above

Question 14

Technician A says that a sliding 5th wheel should be installed on a tandem drive tractor so that its furthest point of forward travel is directly over the bogie centerline.Technician B says that a sliding 5th wheel should be installed on a tandem drive tractor so that its rearmost point of travel should be directly over the rear drive axle centerline.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 15

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?

A) full travel forward
B) directly over the bogie centerline
C) slightly to the rear of the bogie centerline
D) full travel rearward

Question 16

Which of the following is the preferred method of attaching a fifth-wheel base plate to a truck frame?

A) weld 5th wheel base plate directly to the frame using AWS E-7018 electrodes or MIG equivalent
B) bolt angle iron sections to the frame rails and weld 5th wheel base plate to the angle iron sections
C) MIG weld base plate to rail flanges
D) bolt base plate to the rail flanges

Question 17

Which of the following applications would benefit from the use of a compensating fifth wheel?

A) B-train lead trailer with aluminum frame
B) A-train lead trailer with pintle hook
C) yard shunt
D) pick-up and delivery tractor

Question 18

Which of the following describes the role of a trailer upper coupler?

A) built into the truck frame and pivots fore and aft
B) built into the trailer frame and contains the kingpin
C) supports all of the trailer load
D) supports none of the trailer load

Question 19

Which of the following are the two SAE standard size kingpins?

A) 2-inch and 3-inch
B) 3-inch and 4-inch
C) 2-inch and 3 1/2-inch
D) 2 1/2 inch and 3 1/2 inch

Question 20

Which of the following 5th wheels is designed to articulate on two planes,transverse and longitudinal?

A) semi-oscillating
B) fully-oscillating
C) compensating
D) sliding

Question 21

When you are about to couple a tractor 5th wheel to a trailer upper coupler,which of the following must be true?

A) trailer bolster plate should be about 1-inch higher than 5th wheel plate
B) trailer bolster plate should be about 1-inch lower than 5th wheel plate
C) 5th wheel jaws should in their closed position
D) 5th wheel secondary lock should be in latched closed position

Question 22

Technician A says that when a kingpin is welded to an upper coupler,it should be stitch welded in one direction of rotation.Technician B says that an AWS E-11018 electrode is recommended.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 23

When a kingpin flange is bolted to a upper coupler plate,what fasteners are recommended?

A) 5/8-inch Grade 5
B) 5/8-inch Grade 8
C) 3/4-inch Grade 5
D) 3/4-inch Grade 8

Question 24

Which of the following describes what usually causes a high hitch condition?

A) kingpin sits on fifth wheel deck plate
B) kingpin sits on top of lock jaws with locks fully engaged
C) kingpin sits on top of lock jaws with locks not engaged
D) kingpin misses 5th wheel throat entirely

Question 25

Which of the following 5th wheels has a locking mechanism with a small number of moving components?

A) Simplex
B) Holland B-lock
C) Holland A-lock
D) Fontaine No-slack

Question 26

Technician A says that when bolting 5th wheel angle iron brackets to a tractor frame the bolts should be spaced 12-inches apart.Technician B says that 5th wheel angle iron brackets should be bolted to a tractor frame using SAE Grade 8 bolts of at least 5/8-inch.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 27

Before uncoupling a tractor from a semi-trailer,which of the following should be done?

A) ensure the trailer parking brakes are released
B) apply the trailer service brakes
C) lower the trailer dolly legs and raise to take some weight off the tractor
D) ensure the 5th wheel main and secondary locks are both fully engaged

Question 28

What is the usual cause of a bowed upper coupler bolster plate?

A) high hitch coupling
B) overloading
C) aggressive tractor coupling
D) not setting landing gear height before coupling

Question 29

Technician A says that some pintle hooks use hydraulic buffers to limit the effects of trailer ram under braking.Technician B says that some pintle hooks use pneumatic buffers to limit the effects of trailer ram under braking.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 30

When fitting a fifth wheel to a truck frame,what is the minimum distance ahead of the 5th wheel pivot centerline the angle iron brackets should extend?

A) 6-inches
B) 12-inches
C) 18-inches
D) 24-inches

Question 31

Which 5th wheel uses a TouchLoc locking mechanism?

A) Fontaine No-slack
B) Holland XA-SII (Simplex II)
C) Holland B-lock
D) Holland A-lock

Question 32

In an A-train combination,what does a drawbar eye connect to?

A) tractor 5th wheel
B) tractor pintle hook
C) lead trailer pintle hook
D) pup trailer pintle hook

Question 33

Technician A says that an upper coupler kingpin template is used to verify that a kingpin is in satisfactory condition.Technician B says that a kingpin plug is used both when testing and reassembling 5th wheels.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 34

What lubricant do SAF Holland recommend should be applied to the rack and bracket slide path of sliding 5th wheels when serviced?

A) paste on chassis grease
B) spray on 80/20 mixture of engine oil and diesel fuel
C) spray on 80/20 mixture of diesel fuel and engine oil
D) paint on API GL-5 gear lube

Question 35

Which of the following companies is NOT a manufacturer of highway 5th wheels?

A) Jost
B) Fontaine
C) SAF Holland
D) Spicer Dana

Question 36

Technician A says that when the kingpin on a trailer upper coupler wears out,it should be replaced.Technician B says that some OEMs recommend a new repair welding technique to recondition a kingpin rather than rebuild the upper coupler.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 37

When an E-7018 electrode is used to weld a kingpin to an upper coupler plate,which of the following is true of the resulting weld deposit?

A) it will fracture dead center
B) it will fracture at the sides of the weld profile
C) it evenly dilutes the harder kingpin base material with the upper coupler base material
D) it becomes contaminated with carbon slag from the kingpin base material

Question 38

What is the main advantage of using a tapered,removable kingpin?

A) removable in applications where a fixed kingpin could be damaged
B) can couple into both 2-inch and 3.5-inch standard fifth wheel jaws
C) reduces longitudinal thrust forces
D) reduces tractor to trailer torque twist effect

Question 39

When fitting a fifth wheel to a truck frame,what is the minimum distance behind the 5th wheel pivot centerline the angle iron brackets should extend?

A) 6-inches
B) 12-inches
C) 18-inches
D) 24-inches

Question 40

How are most current kingpins attached to the upper coupler assembly?

A) rivets
B) SAE Grade 8 bolts
C) welding
D) SAE Grade 5 bolts

Question 41

What is the maximum hook to latch clearance permitted on highway pintle hook assembly?

A) 3/8 inch (10 mm)
B) 1/2 inch (12.5 mm)
C) 3/4 inch (19 mm)
D) 1-inch (25 mm)

Question 42

Technician A says that hydraulic snubbers on pintle hook assemblies are more common on highway truck trailer applications.Technician B says that pneumatic snubbers on pintle hook assemblies are more common on off-highway applications.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 43

What type of lubricant should be applied to the horn of a pintle hook to maximize its service life?

A) Heavy-duty axle grease
B) Lithium grease
C) Diesel fuel
D) No lubricant is required

Question 44

Which of the following terms is used to describe the means of buffering trailer bump on a pintle hook assembly?

A) shock absorber
B) snubber
C) jounce block
D) rebound accumulator

Question 45

Technician A says that ball hitches cannot be used on highway tractor-trailer combinations.Technician B says that a standard drawbar eye can be connected to a heavy-duty ball hitch.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B