All-Wheel Drive

Question 0

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 0

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

Question 1

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 1

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

Question 2

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 to function as a solid link when necessary.
d. To transfer torque to the front wheels only, on an as needed basis.

Answer 2

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

Question 3

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 3

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 4

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 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 4

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 5

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. This 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 5

d. Test drive the vehicle to confirm the condition.

Question 6

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

a. Talk to the customer. This 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 6

a. Talk to the customer. This is most likely a normal condition.

Question 7

The customer complaint is that when starting on slippery roads, the front wheels seen 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, caused by the "hump" phenomenon.
c. The viscous coupling is slipping, and should be replaced.
d. This is a normal condition, caused by torque multiplication.

Answer 7

b. This is a normal condition, caused by the “hump” phenomenon.

Question 8

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 8

a. a silicone gel

Question 9

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 also 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 multiple 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 9

c. An abnormal condition, required inspection of the planetary gears.

Question 10

Free wheeling hubs are not to be used with this type of transfer case.

a. Part time
b. Full time
c. All type
d. Not used in any

Answer 10

b. Full time

Question 11

Many late model light duty transfer cases use this design for range selection:

a. Bevel gears
b. Spur gears
c. Planetary gears
d. Hypoid gears

Answer 11

c. Planetary gears

Question 12

The “New Process 205” transfer case use a:

a. Planetary gear set
b. Chain drive
c. Combination of both
d. Full gear drive

Answer 12

d. Full gear drive

Question 13

In a part-time four wheel drive, transfer cases divide torque:

a. 45% front, 55% rear
b. 50% front, 50% rear
c. 60% front, 40% rear
d. 85% front, 15% rear

Answer 13

b. 50% front, 50% rear

Question 14

Transfer cases are usually mounted on:

a. The rear of the transmission only
b. Manual transmission only
c. The frame of the vehicle only
d. The frame and the transmission in combination

Answer 14

d. The frame and the the transmission in combination

Question 15

A full size Ford F250 utilizing a NP 205 transfer case is being driven on dry pavement while in four wheel drive. The major concern will be:

a. Drive line slippage
b. Range fork damage
c. Torque bind
d. No concern

Answer 15

c. Torque bind

Question 16

The main difference between a full time and part time four wheel drive vehicle is:

a. The full time input and output shafts are on the same side of the case.
b. Full time transfer cases are made solely of aluminum while part time cases are made of magnesium.
c. The differential operates differently between the two types.
d. The operator does not have to lock the hubs with some full time designs.

Answer 16

d. The operator does not have to lock the hubs with some full time designs.

Question 17

With a NP203 full time transfer case, in oder to obtain greater traction and torque, the operator should place the selector in:

a. High
b. High lock
c. Low
d. Low lock

Answer 17

d. Low lock

Question 18

A differential lock is required with which type of transfer case?

a. Part time
b. Full time
c. Electronic
d. Not needed at all

Answer 18

b. Full time

Question 19

The most important thing to consider when installing after-market tires on a vehicle equipped with Automatic hubs is that:

a. The trad matches side to side for high speed performance.
b. All four tires are of the same circumference.
c. Raised white lettering should all face out.
d. The Aspect Ratio should never be exceeded beyond the manufacturer specification.

Answer 19

b. All four tires are of the same circumference.

Question 20

It is not safe to say that:

a. Transfer cases use a variety of mounting designs.
b. Not all transfer cases utilize locking hubs.
c. All transfer cases use the same lubricant.
d. Transfer case manufacturers are using more electronic controls.

Answer 20

c. All transfer cases use the same lubricant.

Question 21

When disassembling an aluminum transfer case, it is important to:

a. Use the provided pry openings case into the case halves.
b. Use a keenly sharp putty knife to insure complete removal of all gasket material.
c. Use a keenly sharp putty knife to pry between the case halves.
d. Use a torque wrench to remove fasteners as not to damage the soft case metal.

Answer 21

a. Use the provided pry openings cast into the case halves.

Question 22

When driving part-time four-wheel-drive and you want to select 4WD low from 4WD high at 40km/h, you must:

a. First lock the hubs.
b. Step on the clutch.
c. Can't be done.
d. Both A and B

Answer 22

c. Can’t be done.

Question 23

The four different ways to lock the centre differential on a full-time four wheel drive are: viscous coupling, multi disc wet clutch, vari-lock and:

a. Mechanical hub and sleeve lock
b. Hydrogen charged accumulator.
c. Use of special transfer case f-fluid
d. None of the above

Answer 23

a. Mechanical hub and sleeve lock.