Car Talk

What is a Torsion Bar Suspension System?

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The torsion bar is an essential component in vehicles like cars and trucks. In vehicles, it is a long spring-steel element with one end rigidly held to a frame and the other twisted by a lever connected to the axle.  In the torsion bar suspension system, the torsion bar is used as a spring to manage the vehicle’s weight. 

Additionally, there are fewer parts in this kind of suspension system, which also reduces the vehicle’s weight.

By twisting and holding the vehicle’s weight, the torsion bar cushions the impact of the road surface. The force applied is known as torsion force. One end of this road is linked with a handlebar, and the other is linked to the car chassis. 

What is Torsion Bar Suspension?

The torsion bar suspension is quite different than the suspension used in different cars and applications. The use of springs is quite common in suspension systems, which are responsible for absorbing shocks from tires and roads. It also offers additional comfort inside the vehicle. 

In the torsion suspension system, instead of a spring system, the shock is absorbed by the torsion system. To understand how it works, we need to understand the functionality of torsion bars. 

What is a Torsion Bar?

Torsion is a flexible spring that can be twisted around its axes. These bars are designed considering different factors, such as the torque applied during the spring’s torsion, the torsion angle, the torsion bar’s overall size, and its material.

You can locate torsion bars in the suspension of a car or truck, in precision equipment, and in manufacturing machines. The prime reason a torsion is used is its flexibility. Using a stiffer structure, such as a steel bar, will cause load-bearing pressure to be on both wheels and undercarriage. 

Working of a Torsion Bar

A torsion bar functions by opposing the torque applied to it. It produces torque when one end of the rod is twisted and fastened to an immovable object.  When this occurs, the torque is carried by the torsion bar, which promptly returns to its initial position after removing the torque. Generally speaking, a frame is an immovable item. The torsion bar will remain in its position if no force is applied until a force is introduced.

Parameters that Affect Torsion Suspension Stiffness 

You can easily adjust the stiffness of the suspension in the spring system by changing the length of the spring. There are various parameters that you need to take into account that can affect the stiffness of these suspension systems. Some of them are discussed below.

  • Material 

Increased stiffness of the material causes an increase in the stiffness of the suspension. 

  • Length

The increasing length of the suspension bar is directly proportional to the decreasing stiffness of the torsion suspension. 

  • Shape

These bars are generally made from circular shapes. However, these shapes have a substantial effect on the smoothness and stiffness of the suspension bar.

  • Cross-Section  

An increase in cross-section leads to increased stiffness, and the smoothness also decreases. 

Advantages of Torsion Suspension Application 

Here are some of the prime advantages that torsion suspension provides to users: 

  • Space

The torsion bar suspension application takes much less space in comparison to other conventional suspension applications. 

  • Smoothness 

The torsion suspension offers much better smoothness and is also a good application for smooth systems. 

  • Maintenance 

Because it is much easier to deal with these applications, maintenance costs are lower than usual.

  • Vehicle Height

Through suspension application, you can easily adjust the vehicle’s height.  

How Can You Execute Torsion Bar Adjustment?

Sometimes, it becomes necessary to adjust the vehicle’s height. You can do it with the assistance of adjusting pins at the top of the torsion bar frame. The weight on the torsion handle does not change during the adjustment. The steering can feel a bit stiffer as a result of this manipulation with the torsion bar. This is because of a new angle of the joystick. Another possibility is that the adjustment rings have been damaged for an extended period of time, leaving a gap between the joystick of the car and the top of the torsion as it comes underneath the car.

After adjusting the height of the torsion bar, check the vehicle’s alignment to ensure the car’s body weight is properly distributed. 

Torsion Bar Adjustment – Step-by-Step Guide 

When adjusting the torsion bar, perform the following steps: 

  1. Find the torsion under your vehicle. When you do, the rack’s center will have an upward-pointing pin visible. Labeling the bolt to track how many changes you will be making when tightening the bolt is recommended. 
  2. Turning the bolts clockwise will cause them to tighten and increase the amount of load on the torsion . 
  3. After lowering the car, the spring speed will be accessible. Turn the pin counterclockwise, and full rotation of the bolt will provide you with the right results. 
  4. Measure the change in the vehicle’s height after removing the jack. It is crucial for both sides of the front to be on the right level with each other. 
  5. If the edges are unequal, readjust the bolts by repeating the process from the beginning. 


In conclusion, a torsion suspension system provides the necessary spring force for the car’s suspension by using the twisting motion of a steel bar. This system is adopted for its simplicity and durability, especially in applications where robustness is important, such as in off-road vehicles. SAT Japan


Where is the torsion suspension system mostly used?

It is commonly used in SUVs, passenger cars, and trucks. These are popular off-road vehicles because of their robustness and ability to handle challenging terrains. 

Are torsion suspensions appropriate for every kind of car?

The torsion system is versatile and can be used in various vehicles. However, they might not be suitable choices for all types of applications, such as sports cars, where different types of suspension are required for precise handling. 

Can I drive a damaged torsion bar?

You can drive a damaged or broken torsion, but it is important to be careful when turning and driving on rocky roads, as you cannot control it smoothly.

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