Car suspension parts, components and their function
The suspension is a set of particular components in a vehicle that functions to reduce shocks and vibrations in the vehicle due to uneven road surfaces to improve driving comfort and vehicle control.
The vehicle's suspension system's position is generally located between the body (frame) and the wheels. Precisely, at the front wheels and the rear wheels.
Currently, there are two main types of suspension systems. The first is a dependent suspension system, or some people called a rigid suspension system, and the second is an independent suspension system.
Each system has different components; for more details about the types of a car suspension, you can read the article about eight car suspension system types that I posted before. Well, in this article, we will explain the car suspension parts, components and their function.
1. Spring
The first suspension component is a spring. Spring in a car is an elastic object made from steel that is used to absorb mechanical energy. The spring functions to absorb the wheels' shocks and vibrations received from the road so that the shocks and vibrations are not transmitted directly to the vehicle body.
At this time, there are several types of springs used in vehicles, namely:
- Coil Spring; springs made of special spiral-shaped steel rods.
- Leaf Spring; springs made of special steel blades that extend and are flexible with a shape that protrudes to one side.
- Torsion Bar; springs made of special steel rods that are elastic when twisted.
2.Shock absorber
The next suspension component is the Shock Absorber. The function of a shock absorber is to dampen the oscillating force from the spring. When we drive on a bumpy road, the vehicle's wheels will move to follow the contours of the road surface. At this time, the spring will receive the pressure that occurs in the wheel.
The shock absorber will slow down and reduce vibration and movement by converting the kinetic energy from the suspension movement into heat energy released through hydraulic fluids or gases. Therefore, the shock absorber can dampen the vibration of the spring.
3. Ball joint
The next suspension component is the Ball joint. This ball joint is a spherical connection component that can rotate at a certain angle. A ball joint is made of unique steel material that has the function to accept vehicle loads either vertically or in a lateral position. The ball joint also functions as the rotation axis when the vehicle turns.
The naming of ball joints in the vehicle is quite diverse, depending on the position and place where it is placed. Like the example:
- Long tie rod ball joint; ball joint mounted on the steering section.
- Upper arm ball joint; ball joint mounted on the upper arm of the suspension
- Lower arm ball joint; ball joint mounted on lower arm components
For more details about the ball joint names, you can read this article: Car ball joint names in the suspension system.
4. Sway bar
Sway bars are generally installed on both the left and right lower arms through an arrangement of rubber pads, linkages, or ball joints. Meanwhile, in the middle of the sway bar is attached to the car frame through a rubber bushing.
The sway bar is a special steel rod that functions to reduce the vehicle's rolling effect, especially when the vehicle turns sharp or when traveling on bumpy roads.
The following is the function of the sway bar.
- Keep the vehicle stable, especially when the vehicle turns.
- Reducing the car body's tilt caused by centrifugal force when the vehicle turns (rolling effect).
- Increases traction/grip of the tires on the road surface when the vehicle turns.
5. Strut bar
In this suspension system, strut bar components are more commonly found in commercial vehicles that use the Ladder-frame model.
The strut bar is a component in the suspension system with a function to hold the lower arm so that the front wheel tilt angle can be appropriately maintained. The strut bar's end is attached to the lower arm, and the other end is fastened to the cross member using brackets and rubber pads.
The strut bar also functions to hold the lower arm from moving back and forth when it receives a shock from an uneven, bumpy road surface or a push due to braking.
6. Knuckle arm
The next suspension component is the knuckle arm. The knuckle arm is a component that functions as a holder for the wheels, wheel bearings, to the disc or drum brake device.
The knuckle arm is connected to the lower arm and upper arm with a ball joint. The vehicle wheels can move freely and turn in any direction according to the availability of the rotating angle of the ball joint on each arm.
7. Upper control arm
Another suspension component is the Upper control arm or commonly known as the upper swing arm. The upper control arm is generally found in vehicles that use double wishbone or multi-link type suspensions.
The upper control arm is directly connected to the car frame using a bushing or shaft lubricated with grease. The other side of the upper control arm is connected to the knuckle arm through an intermediary ball joint, so it can be said that the upper control arm functions to hold the knuckle arm on the upper side.
8. Lower control arm
The next suspension component is the Lower control arm. The lower control arm is also called the lower swing arm. The lower control arm functions to support the lower knuckle arm connected to the ball joint, while the other side is directly connected to the car frame.
Besides functioning to hold the lower part of the knuckle arm, the lower control arm also functions as a control for the vehicle's wheels' movement, both up and down and back and forth movement control.
9. Lateral control rod
The lateral control rod holds the axle and body in position from pressure and side loads, especially when the car turns. This lateral control rod is generally mounted on the rear suspension only.
10. Bumper suspension
This bumper suspension is a suspension component that is generally made of elastic rubber material. This bumper suspension serves to protect other suspension components due to collisions caused by the spring flexing beyond its maximum limit.
Two types of bumpers are known: bounding for the bumper mounted on the lower control arm and re-bounding bumper mounted on the upper control arm's side. With this bumper suspension, bending or damage to the lower arm or upper arm due to the spring flexing beyond the limit can be avoided.