What is a Car Lower Arm? This is Its Function and How It Works
In the car suspension system, there are various components that assist the performance of the system, including the lower arm of the car. So what is meant by the lower arm? Does it have a significant role? How does this component work? Let's find out the answers to all these questions by paying attention to the following review.
What is a Lower Arm?
As previously explained, the lower arm is one of the components of the car suspension system. As we know, the car suspension system plays a role in maintaining the comfort of passengers and the driver while driving. This system will dampen vibrations and shocks produced when the car passes over damaged or uneven roads. The success of the suspension system's performance is influenced by several components within it, including the lower arm.
In the automotive world, the lower arm is also known as the lower swing arm because it is mounted below the car frame. The lower arm in cars has different designs depending on the type of suspension used. For double wishbone suspension, the lower arm design usually resembles the letter A. For MacPherson suspension, its shape resembles the letter L. And for suspensions used in general vehicles, the lower arm is shaped like the letter I.
Function of the Lower Arm
In the car suspension system, the lower arm has a function and role that is quite important. Its functions are as follows.
1. Controlling Wheel Movement
The lower arm has the main function of controlling wheel movement. This includes upward or downward movement, and forward or backward movement. In controlling this movement, the lower arm will work in synergy with the upper arm. When the car's wheels are in motion, the upper arm will maintain the wheel's position to ensure it is in the specified position. Meanwhile, the lower arm functions to stabilize the wheels when the car is moving.
2. Supporting the Knuckle Arm
Next, the lower arm functions as a support for the knuckle arm. This is because the lower arm can be considered as a housing for the knuckle arm. As we know, the knuckle arm is a suspension component located at the front of the car's wheels. Specifically, it is between the tire and the rim, connected to the car's brake components and the hub.
Through the ball joint embedded in the lower arm, the brake components, wheels, and knuckle arm will be supported. Thus, the knuckle arm can move more freely because it is not directly connected to the lower arm.
Although not directly connected, the knuckle arm still requires the lower arm to bear the car's load to stabilize the wheel movement.
3. Ensuring the Wheels Turn in Unison
The lower arm in the car also has another equally important function, which is to ensure the wheels turn in unison. The lower arm will ensure the wheel movement is synchronized when turning according to the steering angle and the left and right wheels of the car. If the car is steered to the right, the wheels can freely turn in that direction. This also applies when the car turns to the left.
How the Lower Arm Works
The way the lower arm works is quite complex. When the car drives on uneven roads, it will cause vibrations and shock effects. These vibrations and shock effects will be absorbed by the lower arm with the help of lower arm bushings (vibration dampening rubber). When the car turns, the lower arm will maintain the suspension geometry so that the wheel positions are parallel and do not cause excessive friction on the car's tires.
Considering the significant role of the lower arm in maintaining driving safety and comfort, the condition of the lower arm should always be monitored if the car sways, the front seats make squeaking noises, there are rough sounds from under the car, the steering feels heavy, or the brakes jerk. These are signs that the lower arm is damaged and needs to be replaced immediately. Don't forget to replace it at a Daihatsu workshop to get original spare parts and the best service.
