Steering System

Hydraulic power steering uses hydraulic pressure to assist the driver in turning the wheels with less effort.
Its working can be understood in two conditions:
1. Neutral (Straight-Ahead) Position:
When the steering wheel is in the straight-ahead position, the control valve inside the power steering system remains centered.
In this position, the hydraulic fluid flows back to the reservoir without creating pressure.
There is no assistance provided to the steering, so the wheels stay straight without extra force.
2. While Turning:
When the driver turns the steering wheel, the control valve opens and directs high-pressure fluid to one side of the power cylinder.
This pressurized fluid pushes the piston inside the cylinder, which helps move the steering linkage in the desired direction.
At the same time, fluid from the opposite side returns to the reservoir.
This hydraulic force reduces the physical effort required by the driver to turn the wheels, especially at low speeds or during parking.
The system automatically adjusts to provide more help at low speeds and less assistance at higher speeds for better control.

While power steering makes steering easier and smoother, it also has some disadvantages:
1. Higher Maintenance Cost: Power steering systems require additional components like pumps, fluid, and hydraulic lines.
This increases the cost of repairs and maintenance compared to manual steering.
2. Reduced Road Feel: Power steering reduces the effort needed to turn the wheel, but it can also reduce the driver’s sense of the road.
This makes it harder to feel small changes in road conditions, which can affect precise handling.
Other disadvantages include slightly higher fuel consumption due to the extra load on the engine and the risk of fluid leaks in hydraulic systems.

A major benefit of a power steering system is that it reduces driver effort by using hydraulic or electric assist.
This makes steering smoother and easier, especially at low speeds or when parking.
Additionally, power steering reduces the total number of steering wheel turns required to move the wheels from one extreme position to the other.
This full range is called lock to lock — meaning from full left lock to full right lock.
By reducing lock to lock turns, the driver can steer quickly and comfortably with minimal effort.
Options like left to right or right to left describe direction but not the entire steering range.
Therefore, the correct answer is lock to lock.

In a steering gear box, the gears transmit the motion from the steering wheel to the steering linkage.
They also work as reduction gears, which means they reduce the input force required to turn the wheels.
This is done by increasing the gear ratio.
A higher gear ratio means the driver turns the steering wheel more turns, but with less effort, to achieve the same wheel movement.
The gear ratio directly multiplies the driver’s input torque, making steering easier, especially at low speeds.
Output torque is an effect of the gear ratio, not the gear’s design objective itself.
Turning angle and scrub radius are unrelated to the reduction function of the gear box.
Therefore, the correct answer is gear ratio.

The worm and nut with re-circulating ball steering gear is a common type of steering mechanism in heavy vehicles.
It uses a worm gear with a threaded shaft called the worm.
A ball nut, containing re-circulating steel balls, is mounted on the worm.
When the steering wheel turns the worm, the balls roll between the worm and nut threads, reducing friction and moving the nut along the worm.
This movement is transferred to the sector shaft and pitman arm to turn the wheels.
The sector shaft supports the movement but the nut directly engages with the worm.
Therefore, the correct answer is worm.

Caster angle affects how the steering axis tilts from vertical when viewed from the side of the vehicle.
A positive caster angle provides straight-line stability but makes steering effort heavier.
If the positive caster is excessive, it not only increases the steering effort but also transmits more road shocks directly to the steering wheel.
This means the driver feels bumps and vibrations more strongly through the steering.
The front wheel itself absorbs shocks through suspension, but the steering mechanism passes these to the driver’s hands.
Passenger seat and rear axle are not directly affected by caster angle in this context.
Therefore, the correct answer is steering.

When a vehicle’s front wheels are turned fully to one side, each wheel traces a circular path on the ground.
The radius of this path traced by the outside front wheel is known as the turning radius.
The turning radius determines how tightly a vehicle can turn, which is an important factor for maneuverability.
A smaller turning radius allows a vehicle to make sharper turns and park in tighter spaces.
Terms like axial, pre-set, or vertical do not describe this concept in steering geometry.
Therefore, the correct answer is turning radius.

Caster is the angle formed by the steering axis when viewed from the side of the vehicle.
A positive caster provides better straight-line stability but increases steering effort.
On the other hand, a negative caster reduces the effort required to steer the wheels.
This is why vehicles designed for easy maneuvering at low speeds, such as older cars or lightweight vehicles, often have a slight negative caster.
However, excessive negative caster can reduce directional stability at higher speeds.
Options like toe-in or positive camber primarily affect tyre wear and vehicle handling but not directly the steering effort.
Therefore, the correct answer is Negative caster.