Transfer Cases

Question 1

What are the two major types of four wheel drive system?

a) four-wheel and two-wheel
b) transfer case and viscous coupling
c) part-time and full-time
d) all-wheel and four-wheel

Answer 1

c) part-time and full-time

Question 2

Name the type of transfer case where the driver controls the operation.

a) viscous coupling
b) part-time
c) full-time
d) locking hubs

Answer 2

b) part-time

Question 3

To drive the front axle, transfer cases use:

a) a chain.
b) gears.
c) both a) and b)
d) neither a) nor b)

Answer 3

c) both a) and b)

Question 4

The transfer case usually provides three modes of operation:

a) 2L, 3L and 4L.
b) 2L, 2H and 4L.
c) 2H, 3H and 4H.
d) 2H, 4L and 4H.

Answer 4

d) 2H, 4L and 4H.

Question 5

To allow the front and rear drive axles to turn at different speeds, full-time transfer cases may incorporate:

a) a differential or a viscous coupling.
b) locking hubs.
c) both a) and b).
d) neither a) nor b).

Answer 5

a) a differential or a viscous coupling.

Question 6

In a viscous coupling, the space between the disks is filled with:

a) gear oil.
b) transmission fluid.
c) a very thick silicone liquid.
d) none of the above.

Answer 6

c) a very thick silicone liquid.

Question 7

List the available forward ranges of an automatic transfer case (ATC) system.

Answer 7

Auto, 2L, 4L and 4H.

Question 8

What component lets the ATCM know where the transfer case motor is currently positioned?

a) input speed sensor.
b) transfer case control module.
c) transfer case encoder assembly
d) transfer case shift motor

Answer 8

c) transfer case encoder assembly

Question 9

When shifting IN or OUT of 4LO, the transmission must be placed in:

a) park
b) neutral
c) park or neutral
d) any forward gear

Answer 9

b) neutral

Question 10

The purpose of the ATC encoder assembly is to:

a) inform the ACTM as to the current position of the motor.
b) control the ATC motor position.
c) decode information from the ATCM.
d) illuminate the Service 4WD warning lamp.

Answer 10

a) inform the ACTM as to the current position of the motor.

Question 11

According to the manufacturer’s diagnostic procedures, the first step in diagnosing a confirmed symptom in the ATC systemis to:

a) road test the vehicle.
b) use the symptoms table to determine diagnostic direction.
c) use a scan tool to check for the existence of DTCs.
d) perform the ATC system check.

Answer 11

d) perform the ATC system check.

Question 12

During your visual inspection, it is important to check for:

a) after market devices.
b) transfer case fluid level.
c) obvious component damage.
d) all of the above.

Answer 12

d) all of the above.

Question 13

Which of the following conditions would cause no communication between the scan tool and the ATCM?

a) no power to scan tool
b) module not programmed
c) class 2 failure
d) All of the above.

Answer 13

d) All of the above.

Question 14

Older 4WD vehicles engaged the front axle through manually locked:

a) transfer case.
b) lock cylinders.
c) front rotors.
d) front hubs.

Answer 14

d) front hubs.

Question 15

When operating in 2WD with the front axle is disengaged, the front axle’s pinion and ring gear set:

a) transmits torque to the front axle shafts.
b) remains stationary.
c) turns opposite to the rotation of the shift sleeve.
d) none of the above.

Answer 15

b) remains stationary.

Question 16

A motorized front axle actuator:

a) operates quickly.
b) reduces electrical load.
c) is not affected by cold ambient temperatures.
d) all of the above.

Answer 16

d) all of the above.

Question 17

What are the two classifications of 4WD transfer cases?

Answer 17

• chain

- gears

Question 18

What are the four gear ranges on a standard (non-automatic) 4WD transfer case?

Answer 18

N, 2L, 4L and 4H

Question 19

Why is a central differential used in a transfer case?

Answer 19

Allow for speed differences.

Question 20

What are the three types of hub locks used?

Answer 20

• vacuum
• manual
• automatic

Question 21

What are the four types of front axle actuators used?

Answer 21

• Thermo wax pellet
• solenoid
• vacuum
• controlled motor (electric)

Question 22

Which type of actuator is used on an electronically controlled front axle lock (NV-246)?

Answer 22

Pernament magnet motor (electric)

Question 23

What component is used to prevent gear clash when shifting from 2H to 4H while the vehicle is still moving?

Answer 23

Synchro ring (blocker ring)

Question 24

Where is the transfer case motor assembly located?

Answer 24

Left hand side of the transfer case.

Question 25

What are the three purposes of the transfer case motor assembly?

Answer 25

• select the gear ranges
• turns the sector shaft to shift the transfer case
• apply the clutch that applies the front propeller shaft.

Question 26

What are the two purposes of the transfer case motor lock?

Answer 26

• prevent the transfer from changing mode/gear position

- reduces current load

Question 27

What is the purpose of the encoder?

Answer 27

To detect the position that the transfer case is in.

Question 28

What is the purpose of the transfer case switch assembly?

Answer 28

Allows the operator to request specific transfer case functions.

Question 29

How is the information given to the transfer case control module for transfer case operation?

Answer 29

multiplexing

Question 30

What prococedure must be followed when replacing the transfer case control module?

Answer 30

• must match to vehicle’s VIN

- flash the module

Question 31

What are the basic different designs of a central differential in an AWD transfer case?

Answer 31

• planetary gears

- bevel gears

Question 32

What are four ways to control central differential slip on either an AWD or a FWD system?

Answer 32

• viscous coupler
• manual mechanical lock
• hydraulically operated multiple plate clutch
• mechanical clutch

Question 33

A viscous coupling or a multi disc clutch can control what two conditions in an AWD drive system?

Answer 33

• torque output

- speed

Question 34

When a viscous coupling is in operation it applies power (torque) to which axle?

Answer 34

the axle that is not slipping.

Question 35

When a viscous coupling makes a mechanical connection, it is referred to as the:

Answer 35

hump phenomenon

Question 36

An 4WD system complaint of binding or hopping when cornering could indicate:

Answer 36

• seized viscous coupling or clutch pack
• damage to front propeller shaft
• uneven differential action

Question 37

What is the fundamental difference between AWD and 4WD?

a) AWD drives the front wheels most of the time and engages the rear wheels only when needed, 4WD drive powers all 4 wheels all the time.
b) AWD utilizes a centre differential and 4WD has the front and rear axles solidly connected via the transfer case.
c) AWD has the front and rear axles solidly connected via the transfer case, whereas 4WD utilizes a centre differential.
d) AWD systems always have a 50/50 torque split. 4WD vehicles have a 40/60 torque split front to rear.

Answer 37

b) AWD utilizes a centre differential and 4WD has the front and rear axles solidly connected via the transfer case.

Question 38

What is the purpose of a centre differential in an AWD system?

a) To ensure a rigid connection between the front and rear differentials.
b) To allow the vehicle to be switched from two wheel drive to AWD.
c) To act as a diagnostic aid for driveline vibrations.
d) To allow for a speed difference between the front and rear differentials.

Answer 38

d) To allow for a speed difference between the front and rear differentials.

Question 39

What is the purpose of a viscous coupling?

a) To allow the vehicle to be switched from two wheel drive to AWD.
b) To act as a diagnostic aid for driveline vibrations.
c) To allow for a speed difference between the front and rear differentials, but also function as a solid link when necessary.
d) To transfer torque to the front wheels only, on an as needed basis.

Answer 39

c) To allow for a speed difference between the front and rear differentials, but also function as a solid link when necessary.

Question 40

What is the function of a centre differential with a planetary gear unit and a viscous coupling?

a) To allow for a speed difference between the front and rear differentials and, depending upon the design, may allow for a torque split front to rear.
b) To allow for a speed difference between the front and rear differentials, but is not designed for a torque split front to rear.
c) To solidly link the front and rear differentials under all conditions and will not allow a speed difference front to rear.
d) To act as a torque splitter and a driveline diagnostic tool.

Answer 40

a) To allow for a speed difference between the front and rear differentials and, depending upon the design, may allow for a torque split front to rear.

Question 41

What is the function of a centre differential with a bevel gear unit and a viscous coupling?

a) To allow for a speed difference between the front and rear differentials and, depending on the design, may allow for a torque split front to rear.
b) To allow for a speed difference between the front and rear differentials, but is not designed for a torque split front to rear.
c) To solidly link the front and rear differentials under all conditions and will not allow a speed difference front to rear.
d) To act as a torque splitter and a driveline diagnostic tool.

Answer 41

b) To allow for a speed difference between the front and rear differentials, but is not designed for a torque split front to rear.

Question 42

The customer complaint is that his AWD vehicle binds and hops during turns. What would your first step in diagnosing the problem be?

a) Talk to the customer. The is most likely a normal condition.
b) Replace the transfer system.
c) Replace the planetary gears in the transfer system.
d) Test drive the vehicle to confirm the condition.

Answer 42

d) Test drive the vehicle to confirm the condition.

Question 43

The customer complaint is that his 4WD vehicle binds and hops during turns while in 4WD. What would your first step in diagnosing the problem be?

a) Talk to the customer. The is most likely a normal condition.
b) Replace the transfer system.
c) Replace the planetary gears in the transfer system.
d) Test drive the vehicle to confirm the condition.

Answer 43

a) Talk to the customer. The is most likely a normal condition.

Question 44

The customer complaint is that when starting on slippery roads, the front wheels seem to spin a small amount and then traction is regained. The vehicle is equipped with an AWD transfer system with a viscous coupling. After confirming the condition, you conclude:

a) the planetary gear set in the transfer system is faulty.
b) this is a normal condition, cuased by the “hump” phenomenom.
c) the viscous coupling is slipping, and should be replaced.
d) this is a normal condition, caused by torque multiplication.

Answer 44

b) this is a normal condition, caused by the “hump” phenomenom.

Question 45

The viscous fluid in a viscous coupling is:

a) a silicone gel.
b) a silicone emulsion.
c) a silicate implant.
d) a silicate and glycol combination.

Answer 45

qa) a silicone gel.

Question 46

The customer complaint is that the AWD system is making a whining sound. With further investigation, you confirm the noise is from the AWD transfer case. You have alwso confirmed that the AWD system is a planetary gear/multiple plate transfer clutch system. The noise most likely is:

a) a normal condition. All planetary gear sets make some noise.
b) burnt clutches in the mulitple plate transfer clutch system.
c) an abnormal condition, requiring inspection of the planetary gears.
d) an abnormal condition, as the planetary gears appear to be solidly locked.

Answer 46

c) an abnormal condition, requiring inspection of the planetary gears.