Deck 13: Rack and Pinion Steering Gears and Four Wheel Steering

Question 1

At low speeds, a vehicle with a four-wheel steering system has a shorter turning radius than a vehicle with conventional steering.

Answer 1

True

Question 2

All of these statements about a power rack and pinion steering gear mounted behind the front wheel spindle are true EXCEPT:

A) The spool valve is moved by torsion bar twisting during a turn.
B) During a left turn fluid pressure is directed to the left side of the rack piston.
C) During a right turn fluid pressure is directed to the right side of the rack piston.
D) Fluid is returned through the vent tube positioned in the bellows boot.

Answer 2

D

Question 3

In an electronic variable orifice (EVO) steering system, power steering assist is highest when driving at cruising speeds.

Answer 3

False

Question 4

If the lock-to-lock steering wheel rotation is 3.5 turns, and the total front wheel movement during this rotation is 70 degrees, the steering ratio is 20:1.

Question 5

Technician A says when installing the Teflon rings on the control valve in a rack and pinion steering gear, the rings may be heated with a propane torch. Technician B says when installing the Teflon rings on the control valve in a rack and pinion steering gear, an expansion tool may be used. Who is correct?

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

Question 6

Rack and pinion steering gear oil leak diagnosis is being discussed. Technician A says if oil leaks from the pinion end of the housing when the rack contacts the left internal stop, a defective inner rack seal is the problem. Technician B says if oil is leaking from the pinion end of the housing and it is not affected by steering wheel rotation, the pinion seal is leaking. Who is correct?

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

Question 7

All of the following are true about a Magnasteer power steering system EXCEPT:

A) At high speeds more assist is provided, which provides better road feel, firmer steering, and improved directional stability.
B) If the system senses lateral acceleration the steering effort will become firmer in an effort to reduce oversteering by the driver.
C) During low speed operation increased steering assist is provided for minimal steering effort to facilitate parking maneuvers and easy turning.
D) As vehicle speed changes or lateral acceleration occurs the amount of effort required to steer the vehicle can be varied depending on the requirements.

Question 8

A power steering system may contain a fluid cooler.

Question 9

If the lock-to-lock steering wheel rotation is 3:25 turns and the total front wheel movement is 78 degrees the steering ratio is:

A) 13:1
B) 15:1
C) 17:1
D) 19:1

Question 10

Technician A says steering effort imbalance on a power rack and pinion steering gear may be caused by worn rings on the rotary valve. Technician B says when turning the steering wheel to the right or left, low power steering assist may be caused by worn rings on the rotary valve. Who is correct?

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

Question 11

In electronic variable orifice (EVO) steering systems:

A) Full power steering assistance is provided if the vehicle speed is below 10 mph (16 km/h) and steering wheel rotation is above 15 rpm.
B) The control unit increases steering assistance at higher speed to provide improved road feel.
C) Steering assistance is increased if the vehicle is cornering at high speeds.
D) Steering assistance is increased if the vehicle is driven straight ahead at highway speeds.

Question 12

In a column-driven electric power steering system all of the following are true EXCEPT:

A) The steering system may have a 20:1 steering ratio during low-speed cornering.
B) A motor module assembly is bolted to the lower end of the steering column.
C) The steering shaft torque sensor is the most important input used by the power steering control module.
D) At low speeds more steering assist is provided.

Question 13

The breather tube in a rack and pinion steering gear allows air to flow from one bellows boot to the other boot during a turn.

Question 14

In a center take-off rack and pinion steering gear, the tie rods are connected to the ends of the rack.

Question 15

Bent tie rods may be heated and straightened.

Question 16

In a rack and pinion steering gear, the rack maintains the tie rods in parallel position in relation to the lower controls arms.

Question 17

Rack and pinion steering gears have become commonplace on both passenger cars and light trucks.

Question 18

Technician A says a power rack and pinion steering gear requires a breather tube to allow air to flow from one bellows boot to the other during a turn. Technician B says in a rack and pinion steering gear, a breather tube is connected between the bellows boots and the power steering pump return hose. Who is correct?

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

Question 19

Compared to a recirculating ball steering gear and parallelogram steering linkage, a rack and pinion steering gear and linkage has fewer friction points.

Question 20

During a right turn, the spool valve movement inside the rotary valve directs power steering fluid to the left side of the rack piston.

Question 21

The inside of both bellows boots are contaminated with power steering fluid on a rack and pinion steering gear. Technician A says if fluid is leaking past a rack seal into one boot, oil may flow through the breather tube to the opposite boot. Technician B says that there should be fluid in the bellows boot, and this is a normal condition. Who is correct?

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

Question 22

Technician A says when a vehicle with an electronic variable orifice (EVO) steering system is operating below 10 mph and the steering wheel rotation is above 15 rpm, power steering assist is increased. Technician B says on this vehicle, power steering assist is decreased when the vehicle speed is above 25 mph. Who is correct?

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

Question 23

Technician A says that on an electronically controlled four-wheel steering system, the rear wheels are steered in the same direction as the front wheels at vehicle speeds below 10 mph. Technician B says that on an electronically controlled four-wheel steering system, the rear wheels are steered in the opposite direction to the front wheels at speeds above 45 mph. Who is correct?

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

Question 24

On a power steering rack system, a customer complains that the steering wheel is not level. The concern is verified during a road test. It is also noticed that the wheel is sometimes off to the right, and sometimes off to the left. The most likely cause of this condition is:

A) Incorrect preload on rack guide
B) Incorrect tire pressure
C) Wheel alignment being out of specifications
D) Worn mounting bushings for the power steering rack housing

Question 25

In a power rack and pinion steering gear the breather tube:

A) Allows air into the rotary valve area while driving straight ahead
B) Moves air from one boot to the other during a turn
C) Prevents pressure buildup in both rack piston chambers when driving straight ahead
D) Vents the right rack piston chamber during a left turn

Question 26

Electronic power steering (EPS) operation is being discussed. Technician A says the steering sensor informs the EPS control module regarding the direction of steering wheel rotation. Technician B says the interface in the steering sensor amplifies the DC voltage signal from the steering sensor. Who is correct?

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

Question 27

Inputs in the electronic variable orifice (EVO) steering system include the:

A) Throttle position sensor
B) Coolant temperature sensor
C) Intake air temperature sensor
D) Vehicle speed sensor

Question 28

Technician A says when backing up a trailer, a four-wheel steering system on the tow vehicle provides better trailer response to vehicle steering inputs. Technician B says when towing a trailer, a four-wheel steering system on the tow vehicle reduces the articulation angle between the tow vehicle and the trailer during lane changes. Who is correct?

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

Question 29

An electronic power steering (EPS) system is being discussed. Technician A says if the engine stalls and the ignition switch is on, the EPS remains operational. Technician B says if the steering wheel is turned and held fully in one direction, the power module reduces current flow through the steering gear motor to prevent motor overheating. Who is correct?

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

Question 30

A technician notices during a road test for a pulling complaint that the steering wheel is slow to return to center and requires higher than normal steering effort. The most likely cause of this condition could be:

A) A worn lower ball joint
B) Tire pressure is set too high
C) A loose outer tie rod joint
D) An over-adjusted steering rack preload

Question 31

The power steering pump belt breaks on a rack and pinion power steering system. Under this condition:

A) The spool valve no longer moves inside the rotary valve when the steering wheel is turned.
B) The steering operates like a manual steering system, and steering effort is higher.
C) Power steering fluid may be forced from the rack seals when the steering wheel is turned.
D) The torsion bar may be broken when the front wheels are turned to the right or left.

Question 32

Technician A says the steering system's ability to isolate road shock from the steering wheel is reduced when the number of friction points is reduced. Technician B says a steering system has increased road feel when the number of friction points is reduced. Who is correct?

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

Question 33

What are the two input sensors in an electronic variable orifice (EVO) steering system?

Question 34

If an electrical defect occurs in a 4WS system the:

A) Positive phase rear wheel steering is cancelled
B) Negative phase rear wheel steering is increased
C) Positive phase rear wheel steering angle is increased, and negative phase rear wheel steering is decreased
D) Rear wheels remain in the centered position

Question 35

In a center take-off power rack and pinion steering gear, the tie rods are attached to:

A) The ends of the rack
B) Rack studs
C) A moveable sleeve
D) Rack couplings

Question 36

The component in a rack and pinion steering gear that compares to the center link in a parallelogram steering linkage is the:

A) Rack
B) Inner tie-rod ends
C) Pinion
D) Outer tie-rod ends

Question 37

Hybrid vehicles are equipped with electronic power steering for all of the following reasons EXCEPT:

A) To conserve fuel and reduce emissions
B) Because there is no room for conventional power steering
C) Because the internal combustion engine is shut off during idle operation
D) The power steering remains operational during engine idling

Question 38

Power rack and pinion steering gear operation are being discussed. Technician A says the position of the rotary valve inside the spool valve directs the fluid to the appropriate side of the rack piston. Technician B says during a right turn, fluid is directed to the right side of the rack piston and the rack is moved to the left. Who is correct?

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

Question 39

On a four-wheel steering (4WS) system, all of the following statements are true EXCEPT:

A) A 4WS system reduces tire wear
B) A 4WS system reduces yaw forces on the vehicle at higher speeds
C) A 4WS system improves vehicle maneuverability at low speeds
D) A 4WS system provides a smaller turning circle

Question 40

Where is the actuator solenoid mounted in an electronic variable orifice (EVO) steering system?

Question 41

Compared to a recirculating ball steering gear, a rack and pinion steering gear provides:

A) Increased road feel
B) Improved capability to isolate road noise
C) Better capability to reduce steering harshness on road irregularities
D) Increased capability to absorb steering kickback

Question 42

Why does an electronic variable orifice (EVO) steering system reduces power steering assist at higher speeds?

Question 43

For a four-wheel steering system, describe the effect on turning circle diameter.

Question 44

What are the advantages of the four-wheel steering (4WAS) system?

Question 45

Describe the fluid movement in the rack piston chamber in a rack and pinion steering gear during a left turn.

Question 46

When a vehicle with an electronically controlled four-wheel steering system is stopped with the engine idling, steering wheel rotation causes the rear wheels to steer in what direction?

Question 47

When is fluid directed to the appropriate side of the rack piston chamber by the spool valve and the rotary valve position?

Question 48

What does the electronic module operate in an electronically controlled four-wheel steering system?

Question 49

Explain the procedure that must be followed when removing a steering gear on an air bag-equipped vehicle.

Question 50

Explain the procedure for measuring steering wheel free play.

Question 51

When the torsion bar twists, it changes the position of what?

Question 52

What are the advantages of a four-wheel steering system while parking a vehicle?

Question 53

What are the tie rods attached to on a center take-off power rack and pinion steering gear?

Question 54

Compared to a recirculating ball steering gear and parallelogram steering linkage, a rack and pinion steering system transfers more what to the steering wheel?

Question 55

Explain the importance of rack bellows boot inspection and the required frequency of this inspection.

Question 56

For an electronic variable orifice (EVO) steering system, describe the driving conditions required to provide high-power steering assistance.

Question 57

Describe the advantages and disadvantages of a rack and pinion steering system.

Question 58

During a right turn, what causes the power steering pump to force fluid into the right side of the rack chamber, and allow fluid to be removed from the left side of this chamber?

Question 59

What are the tie rods connected to on an end take-off power rack and pinion steering gear?

Question 60

In an electronically controlled four-wheel steering system, where is the front main steering angle sensor located?

Question 61

What are the advantages of a four-wheel steering system while operating at higher vehicle speeds?