Deck 126: Four-Wheel-Drive and All-Wheel Drive

Question 1

A customer complained of excessive vibration while cornering and accelerating at the same time. Technician A says that a fault in the transfer case is the most likely cause. Technician B says that the vibration may be normal if the vehicle is equipped with Cardan U-joints at the front wheels. Which technician is correct?

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

Answer 1

Technician B only

Question 2

Technician A says that the gear ratios of both differentials are the same in a four-wheel-drive vehicle.Technician B says that the rear differential has a slightly higher ratio (lower number) than the front differential. Which technician is correct?

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

Answer 2

Technician B only

Question 3

Technician A says that most transfer cases have a built in oil pump. Technician B says that most transfer cases use a heavy grease as a lubricant. Which technician is correct?

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

Answer 3

Technician A only

Question 4

Technician A says that a vehicle equipped with part-time four-wheel drive should be driven in four-wheel drive only on slippery surfaces. Technician B says that full-time four-wheel-drive vehicles use a center differential in the transfer case. Which technician is correct?

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

Question 5

Which type system uses a one speed transfer case and a center differential with a viscous coupling?

A)All wheel drive
B)Full time 4WD with automatic locking hubs
C)Full time 4WD
D)Part time 4WD

Question 6

Technician A says that a transfer case may use GL-4 gear lube such as SAE 80W-90. Technician B says that a transfer case may use automatic transmission fluid (ATF) such as Dexron III. Which technician is correct?

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

Question 7

A transfer case is extremely noisy in all selections except neutral (N)Technician A says the drive chain may be stretched, causing the noise as it hits the inside of the case. Technician B says that one or more of the transfer case bearings could be defective. Which technician is correct?

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

Question 8

A transfer case is difficult to shift (range shift). Technician A says that the shift linkage or shift fork may be worn or damaged. Technician B says that the blocking ring may be worn or damaged. Which technician is correct?

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

Question 9

Two technicians are discussing the towing of a four-wheel-drive vehicle. Technician A says that the vehicle should be transported on a flatbed truck to avoid the possibility of doing damage to the drive train. Technician B says that the wheels not lifted off the ground by the tow truck should be placed on a dolly to prevent doing damage to the drive train. Which technician is correct?

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

Question 10

Two technicians are discussing the front axle disconnect mechanism. Technician A says that the front axles are only disconnected if the vehicle is being towed. Technician B says that this unit is only used on
All-wheel-drive vehicles. Which technician is correct?

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

Question 11

Two technicians are discussing the purpose of a transfer case in a four-wheel-drive system. Technician A says it transfers power to an additional axle. Technician B says some transfer cases have two speeds. Which technician is correct?

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

Question 12

When part-time 4WD vehicles in 4WD are engaged in a turn, which of these occur?

A)The front wheels will have reduced toe-out on turns
B)The rear wheels travel faster and farther than the front wheels
C)The rear wheels turn faster and farther than the front wheels
D)The front wheels travel faster and farther than the rear wheels

Question 13

Driveline wind-up on a part-time 4WD system results in all of the listed conditions EXCEPT ________.

A)Low traction situations from heavy rain, mud, or snow
B)No differential action between the front and rear axles
C)The front wheels tend to scoot along the pavement causing a driveline vibration
D)The turning radius is different for the left and right wheels as well as the front and rear wheels

Question 14

Technician A says a 4WD transfer case is an auxiliary 2-speed transmission. Technician B says a planetary gearset provides a low and high range. Which technician is correct?

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

Question 15

Technician A says full time 4WD also allows the driver to select 2WD or 4WD. Technician B says part-time 4WD includes a differential or viscous coupling that allows the front and rear axles to rotate at different speeds. Which technician is correct?

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

Question 16

A transfer case contains all of the following components, EXCEPT ________.

A)Shift mechanism
B)Four drive sprockets
C)Front output shaft
D)Planetary gearset assembly

Question 17

Two technicians are discussing the viscous coupling used in all-wheel drive systems. Technician A says a viscous fluid such as a silicon-based oil is added to the assembly and fills the areas between the clutch plates. Technician B says the viscous coupling is active during equal traction conditions. Which technician is correct?

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

Question 18

The planetary gearsets used in transfer cases consist of all of the following components EXCEPT ________.

A)Planet carrier assembly
B)Internal ring gear
C)Forward clutch
D)Sun gear

Question 19

An AWD transfer case must include a ________.

A)Low-range gear set
B)Shifter for the front output shaft
C)Differential
D)All of these

Question 20

Technician A says some front 4WD hubs must be manually locked and unlocked. Technician B says some front 4WD hubs can be automatically locked and unlocked. Which technician is correct?

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

Question 21

Technician A says the held member of a planetary gearset is called the drive member. Technician B says the held member of a planetary gearset is called the reaction member. Which technician is correct?

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

Question 22

Which component is used in some transfer cases to prevent driveline windup?

A)Planetary gear differential
B)Viscous coupling
C)Standard bevel gear differential
D)Any of these can be used to prevent driveline windup

Question 23

Technician A says some 4WD vehicles use a solid front axle. Technician B says some 4WD vehicles use halfshafts to send torque to the front wheels. Which technician is correct?

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

Question 24

What 4 wheel drive system is shown in this drawing of a front axle?

A)Rear axle disconnect system
B)Axle disconnect mechanism
C)Not enough information
D)Planetary gear set