Mechanical Basics

What is Steering Gear Box?

A Steering Gear Box is an Automobile driving system that uses the gears to steer the vehicle in the required direction or it is used to convert the rotation of the Steering Wheel into Swirling Movement of the Wheels. The Steering Gear System consists of links, pairs, and mechanism that are connecting to the gear or gear box.

In the olden days, the steering system consists of only links, and pairs to steer the vehicle; due to this, the application of the driver’s effort is more. Therefore, the gears are introduced to decrease the effort of the driver while steering the vehicle.

The Gears that are used in the steering system are called “Steering Gears”. The gears are fixed or pivoted between the links to decrease the effort. With the help of these gears, the rotary motion is transferred to linear motion or vice versa.

Types of Steering Gear Box:

We can find a number of steering gear boxes with different gearing systems, the types of steering gear box are as follows: 

1. Worm and Nut Steering Gear Box:

Worm and Nut Steering Gear Box is a type of gear box that acts as a bolt and nut system. As we know that the bolt consists of external threading and the nut consists of internal threading; the bolt is inserted in to nut and tightened.

Steering Gear, Types of Steering Gear Box and Advantages of Power Steering

Similarly, a nut meshes with the bolt called worm gear and rotary motion is achieved; when the worm is rotated, the system will move back and forth. This steering gear system is also called a re-circulating ball type. The nut and worm consist of sphere-shaped grooves over the threading whereas; the steel balls can fit in.

Due to the presence of these balls, the movement between nut and worm is free, (similar to the bearing system) and it will reduce the friction also.

2. Worm and Sector Steering Gear Box:

In worm and sector steering gear box, the components or gears used are worm and sector. As we know, the sector is the quarter portion of a circle and the sector gear also looks the same and consists of teeth. The teeth of the sector mesh with the worm gear and both sector and worm gears contact are achieved.

Steering Gear, Types of Steering Gear Box and Advantages of Power Steering

As the steering wheel and worm gear rotated, the sector attached to the pitman arm shaft with slide. The pivot makes an arc of 70 degrees maximum and that is the maximum angle that the wheel can turn. The ball bearing system is used between the gears for free play.

In this, a lash adjustment screw is also provided so that the sector can be moved closer and farther away from the worm gear to control the backlash between the sector and worm threads.

The disadvantage of the worm and sector gear steering type is that “it develops more friction.” To overcome this disadvantage, the Worm and Roller Steering Gear Box is proposed. 

3. Worm and Roller Steering Gear Box

The Worm and Roller Steering Gear Box is much like the worm and sector, the sliding movement as like in worm and sector is absent in worm and roller, instead of sliding movement the rolling movement is introduced with the help of rollers so that the effort of drivers is less.

Steering Gear, Types of Steering Gear Box and Advantages of Power Steering

Due to the rollers, the friction between the gears is reduced and the effort required to turn the steering will be less. The hourglass shape allows the roller to stay in better contact with the worm teeth even at the ends of worm gear. 

4. Cam and Lever Steering Gear Box.

In this, the worm gear can be called Cam, the inner end of the pitman arm shaft has a lever that contains Tapered Stud.

Steering Gear, Types of Steering Gear Box and Advantages of Power Steering

The stud engages with the cam so that when the cam is turned, the lever moves to back and forth. When the tapered stud is fixed in the lever, then the cam cannot rotate.

The vehicles with this type of steering gear, the stud is used to mount in bearings that make it roll in cam groove instead of sliding.

5. Rack and Pinion Steering Gear Box.

Steering Gear, Types of Steering Gear Box and Advantages of Power Steering

In Rack and Pinion Steering Gear Box, the teeth over the straight bar are called Rack and teeth over sphere-shaped is called Pinion. The rack is connected to the steering arms by tie rods that are adjustable to maintain a proper angle.

As the steering wheel is rotated, the pinion gear on the end of the steering shaft rotates. The pinion moves the rack in left and right directions to operate the steering linkage.  

Rack and pinion gear is used on small passenger vehicles where a high degree of precision steering is required.

So, these are the types of steering gear box, now let us study the power steering system.

What is Power Steering System?

Power Steering System is an advanced steering technology. The hydraulic fluid is used as the source to turn the wheels. Power Steering consists of a hydraulic tank and pipes connected to the wheel. When the steering shaft is turned, the hydraulic is released from the tank and pushes the wheels to the required direction and angle. Due to this, the effort required to turn the wheels will be less and efficient.

Advantages of Power Steering:

The advantages of power steering are as follows:

  • The effort usage is less.
  • No friction will develop.
  • Flexible turning and steering can be achieved.


Every gear box consists of even one disadvantage in usage, the new technology and system are proposed to rectify and overcome those disadvantages. Whereas the mechanical components are supposed to move and that movement will definitely develop the friction too so, the power steering will be a friction-less and hydraulic operating system. It will help the automobiles to turn smoothly and efficiently. So, the power steering will be much better than other steering gear boxes.

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