Deck 23: Heavy-Duty Truck Axles

Question 1

What is a drive axle ring gear either bolted or riveted to?

A) axle shafts
B) differential case flange
C) bearing cage
D) pinion gear

Answer 1

B

Question 2

Which of the following best describes how differential action takes place during cornering?

A) outside wheel rotates faster than the inside wheel
B) outside wheel rotates slower than the inside wheel
C) inside wheel is accelerated to the speed of the outside wheel
D) outside wheel is braked to the speed of the inside wheel

Answer 2

A

Question 3

Which of the following describes amboid gearing?

A) axis of the drive pinion is above the centerline of the ring gear
B) axis of the drive pinion is below the centerline of the ring gear
C) drive pinion meshes the ring gear at its centerline
D) none of the above

Answer 3

A

Question 4

Which ONE of the following statements is TRUE?

A) all two-speed axles use double-reduction
B) double-reduction axles are always two-speed axles
C) all tandem drive axles are double-reduction
D) single-reduction axles are seldom used in trucks

Question 5

Which of the following axle hub arrangements could allow a wheel to fall off should the axle half-shaft break?

A) semi-floating
B) full-floating
C) both A and B
D) neither A nor B

Question 6

Which of the following truck drive axle configurations uses two gearsets to provide both an additional gear reduction and greater torque at the drive wheels?

A) single-reduction axle
B) tandem drive axles
C) power divider
D) double-reduction axle

Question 7

When a differential carrier is equipped with a lube pump,where is pressurized lubricant delivered to?

A) interaxle differential and front bearings
B) ring and pinion gearset
C) all of the gears and bearings in the axle
D) drilled passages to the planetary gears

Question 8

Which part of a truck differential carrier assembly contains a spider and four pinions?

A) differential
B) crown gear
C) pinion
D) ring gear

Question 9

Which of the following would be conditions that could result in spinout in a tandem drive truck?

A) loss of traction on a slippery surface
B) backing under a trailer parked on loose gravel
C) timing failure of the front brakes
D) both A and B

Question 10

Which of the following best describes the function of a power divider used on a tandem drive heavy duty truck?

A) locks out differential action between the wheels on either end of the axle
B) when locked,it eliminates interaxle differential action between tandem drive axles
C) when not locked out,it divides torque between tandem drive axles
D) both B and C

Question 11

Which of the following is another name for a truck differential carrier housing?

A) dead axle
B) pusher axle
C) banjo housing
D) accordion housing

Question 12

Which of the following truck differential carrier types can be used in tandem axle configurations?

A) single-speed
B) two-speed
C) three-speed
D) all of the above

Question 13

On which of the following axle types would you find a kingpin?

A) tandem drive axles
B) steering axles
C) trailer lift axles
D) tag axles

Question 14

Where would a pusher axle usually be located on a highway truck?

A) in front of the steering axle
B) immediately behind a steering axle
C) in front of a rear drive axle
D) immediately behind a rear drive axle

Question 15

When a drive wheel spinout occurs,why is the interaxle differential more susceptible to damage than the differential carriers?

A) turns at a higher speed
B) no differential action occurs in either of the differential carriers
C) it does not rotate
D) differential carriers turn at a higher speed

Question 16

Which of the following is another way of saying power divider?

A) controlled traction differential
B) interaxle differential
C) two-speed differential
D) three-speed differential

Question 17

Where would a tag axle usually be located on a highway truck?

A) in front of the steering axle
B) immediately behind a steering axle
C) in front of a rear drive axle
D) immediately behind a rear drive axle

Question 18

What is the final drive component of a truck drive axle usually known as?

A) rear transaxle
B) differential carrier
C) dead axle
D) power divider

Question 19

What components are directly responsible for changing the direction of powerflow by 90 degrees in a drive axle carrier?

A) differential gearing
B) crown and pinion
C) planetary reduction gearing
D) axle shafts and side gears

Question 20

When the differential lock of a single-reduction axle is engaged,which of the following components must rotate at the same speed?

A) differential case and both axle shafts
B) both axle shafts and the drive pinion
C) drive pinion and crown gear
D) drive pinion and both axle shafts

Question 21

Which of the following is an advantage of an air-lift axle?

A) increases load carrying ability of the truck
B) can be raised to avoid tire scuffing in turns
C) can be proportioned to balance weight distribution through the chassis
D) all of the above

Question 22

When spiral cut pinion and crown gears intermesh so that the pinion intersects the crown slightly below its axis,the gear is known as:

A) amboid
B) hypoid
C) bevelled
D) spurred

Question 23

Technician A says that a power divider on a tandem drive axle truck is always integrated in the forward differential carrier.Technician B says that the power divider on a single drive axle truck can be locked out by a switch on the dash.Who is correct?

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

Question 24

How is drive torque usually transmitted to the drive axle shafts in a heavy truck application?

A) internal splines in the crown gear hub
B) external splines in the crown gear hub
C) internal splines in the side gears
D) external splines in the side gears

Question 25

What component is used to connect the steering knuckles on a steer axle so they move together when turning effort is applied?

A) steering control arm
B) Pitman arm
C) tie rod
D) drag link

Question 26

Which of the following driving conditions should a power divider be locked out?

A) backing up to couple a trailer on a loose gravel surface
B) pulling away on icy road surface
C) full load standing start on wet pavement
D) all of the above

Question 27

Technician A says that lift and tag axles can both be classified as dead axles.Technician B says that all steering axles are dead axles.Who is correct?

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

Question 28

In a typical interaxle differential,what do the differential pinions rotate on?

A) spider
B) crown gear
C) axle shafts
D) propeller shaft

Question 29

Technician A says that hypoid gears drive forward on the convex side of the crown gear teeth.Technician B says that hypoid gearsets require EP rated mineral base lubes only and synthetics are not yet approved.Who is correct?

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

Question 30

When a two-speed rear drive axle is used in a truck,which of the following factors must be compensated for to produce accurate driver information display data?

A) speedometer input
B) tachometer input
C) inter-axle differential switch status
D) differential oil temperature

Question 31

Technician A says that during a one-wheel spinout on a tandem drive tractor,the spinning wheel can rotate up to four times faster than the all-four wheel equivalent when torque is properly divided.Technician B says that when a spinning wheel finds traction after a spinout,the drivetrain is shock-loaded.Who is correct?

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

Question 32

Technician A says that a hypoid gear typically has a smaller diameter and smaller teeth than an equivalent spiral bevel gear.Technician B says that hypoid gears have greater torque capacity than equivalent spiral bevel gears.Who is correct?

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

Question 33

What is the maximum amount of available torque that can be transmitted to one of the drive axles when a torque proportional interaxle differential is used?

A) 25%
B) 50%
C) 75%
D) 90%

Question 34

Which of the following single axle weight specifications would represent the highest rating for a highway semi-trailer in most jurisdictions?

A) 17,000 pounds (7,700 kg)
B) 19,000 pounds (8,600 kg)
C) 34,000 pounds (15,400 kg)
D) 50,000 pounds (22,700 kg)

Question 35

Technician A says that when a full-floating axle shaft is used,the axle shaft supports the weight of the truck on the wheel end.Technician B says that full-floating axle shafts can be removed from a truck without removing the wheel.Who is correct?

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

Question 36

Technician A says that hypoid gearsets are more likely to be found in the forward differential carrier of a tandem drive set.Technician B says that when amboid gearing is used,it is more likely to be found in the rear differential carrier of a tandem drive set.Who is correct?

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

Question 37

Which truck OEM is associated with torque proportional differentials?

A) Freightliner
B) Kenworth
C) Navistar International
D) Mack Trucks

Question 38

Technician A says that some trailers use hollow box-section beam axles.Technician B says that some trailers use hollow round-section beam axles.Who is correct?

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

Question 39

When a differential carrier is described as single reduction,where does the gear reduction actually take place?

A) differential gearing
B) planetary carrier
C) propeller shaft and pinion
D) pinion and crown gearset

Question 40

Technician A says that when a highway truck uses two steering axles,one is located at the front of the chassis and the other at the rear.Technician B says that when a highway truck uses two steering axles one is driven and the other is not.Who is correct?

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