Deck 8: Four Wheel Drive Systems Servicing Four-Wheel Drive Systems

Question 1

Technician A says there may be three drive shafts connected to a transfer case. Technician B says one drive shaft is connected to the transfer case, directly from the transmission, and the other two are for driving the front and rear axles. Who is correct?

A) A only
B) B only
C) both A and B
D) neither A nor B

Answer 1

C

Question 2

Part-time four-wheel drive systems are automatically controlled systems.

Answer 2

False

Question 3

The _____, often referred to as the interaxle differential, allows the front and rear wheels to turn at different speeds and with different amounts of torque.

A) open differential
B) rear differential
C) center differential
D) front differential

Answer 3

C

Question 4

Full-time four-wheel drive _____.

A) is never disconnected
B) must be disconnected by a technician
C) is disconnected during off-road use only
D) is used with manual transmissions only

Question 5

Four-wheel-drive is most useful when a vehicle is traveling off the road or on any slippery surface.

Question 6

Technician A says a transfer case is an extra gear box on the back of a transmission. Technician B says a transfer case is mounted between the engine and the transmission. Who is correct?

A) A only
B) B only
C) both A and B
D) neither A nor B

Question 7

Although the principles of operation are similar for all 4WD units, the components, location, and controls of the various systems differ primarily according to _____.

A) car make and model
B) body style
C) engine specifications
D) manufacturer and application

Question 8

Most transfer cases, with low range available, use planetary gearsets.

Question 9

Some vehicles may be shifted into four-wheel drive at any time.

Question 10

A locking hub is a type of clutch that engages the outer ends of the axle shafts from the wheel hub.

Question 11

All-wheel-drive systems give the driver the option of 2WD or 4WD.

Question 12

The Society of Automotive Engineers (SAE) provides standard definitions applicable to AWD and 4WD systems which is used consistently by manufacturers to provide clarity.

Question 13

Technician A says the purpose of a transfer case is to transfer power to an additional drive axle. Technician B says most transfer cases have two speeds which affect the overall gear ratio of the vehicle. Who is correct?

A) A only
B) B only
C) both A and B
D) neither A nor B

Question 14

The outer case of the transfer case is made of magnesium, aluminum, or cast iron and is filled with lubricant.

Question 15

Part-time four-wheel drive _____.

A) must be disconnected when driving off-road
B) cannot be disconnected by the driver
C) is usually disconnected when driving on pavement
D) must be disconnected by a technician

Question 16

Both 4WD and AWD systems add cost and weight to a vehicle.

Question 17

A viscous clutch, cone clutch, or a multiple-plate clutch are three types of clutches that may be used in a(n) _____ differential.

A) limited-slip center
B) center
C) open
D) closed

Question 18

The _____ has the role of recommending specifications and practices for the automotive industry.

A) shop owners union
B) manufacturer
C) shop employees union
D) Society of Automotive Engineers (SAE)

Question 19

A 4WD vehicle may be shifted into four-wheel drive _____.

A) only while stopped
B) only while moving
C) at any time
D) only according to the owner's manual instructions

Question 20

Most transfer cases use drive chains.

Question 21

What is meant by "shift on the fly" 4WD?

Question 22

Briefly distinguish between a 4 × 2 and a 4 × 4 vehicle.

Question 23

In a 4WD system with an open differential, power is applied to which drive wheel(s)?

Question 24

What term refers to a projecting tooth on a wheel or cylinder that engages with the links of a chain to make it move forward?

Question 25

What type of system typically powers a second axle only after the first begins to slip?

Question 26

Names the parts indicated by the arrows in the figure of the typical arrangement of 4WD components.

Question 27

What is driveline windup?

Question 28

Why are locking hubs also called freewheeling hubs?

Question 29

What is the difference between part-time and full-time 4WD?

Question 30

What are the two speed ratios in a 4WD vehicle operating in four-wheel drive?

Question 31

Technician A says seals that are incorrectly installed can cause a leak in a transfer case. Technician B says noises in a transfer case or a differential can be caused by bad bearings. Who is correct?

A) A only
B) B only
C) both A and B
D) neither A nor B

Question 32

Technician A says power can be locked into all four wheels merely by turning the locking hubs into the locked position. Technician B says some transfer cases use an electric switch to engage 4WD. Who is correct?

A) A only
B) B only
C) both A and B
D) neither A nor B

Question 33

What is a transfer case?

Question 34

_____ are often used to link the input and output shafts in a transfer case and serve as a link that does not influence gear ratios.

A) Drive chains
B) Sprockets
C) Locking hubs
D) Pin and rocker joints

Question 35

What is the central gear in a planetary gearset around which the rest of the gears rotate?

A) sun gear
B) hypoid gear
C) annulus gear
D) sprocket

Question 36

Describe the construction of a planetary gearset.

Question 37

_____ systems automatically react to normal or slippery road conditions and are not designed for off-road use; rather, they are designed to increase vehicle performance in poor traction situations.

A) 4WD
B) AWD
C) FWD
D) RWD

Question 38

What are the three classifications of transfer cases and what are their ranges?

Question 39

According to the SAE, what is a full-time 4WD system?

Question 40

What are the purposes of locking hubs on a four-wheel drive vehicle?