When we think of automotive performance, we think of power, the need for speed, the roaring sound of the engine, and how fast the vehicle will go from zero to 60 miles per hour. However, all this power and speed is useless if the driver is unable to control the vehicle and is not comfortable while driving. Therefore, the automotive suspension is a crucial vehicle system.

The primary functions of the suspension system include maximizing the contact between the tires and the road surface, providing steering stability and good handling, evenly supporting the weight of the vehicle (including the frame, engine, and body), and ensuring the comfort of passengers by absorbing and dampening shock. Your vehicle's suspension system works hard to withstand a considerable amount of stress, compared to other major vehicle systems.

The suspension system consists of tires, the air in the tires, springs, shock absorbers, struts, arms, bars, linkages, bushings, and joints. The suspension system components are located between the frame of the vehicle and the road. Well-tuned suspensions will absorb bumps and other imperfections in the road allowing the people inside the vehicle to travel safely and comfortably.

 

 

The tires and the amount of air in the tires are a fundamental part of the suspension system. The tires are the only part of the vehicle that come in contact with the road. This means they have to steer and put power to the ground simultaneously while also being responsible for stopping the vehicle. The suspension system requires the wheels and tires to travel up and down to absorb the shock from bumps. The rubber tires and air in the tires also soften the ride over hard surfaces and conform to slightly uneven and rough surfaces.

Shock absorbers, also known as shocks, are hydraulic oil-filled cylinders that force the suspension to compress and decompress at a consistent rate, to prevent the springs and vehicle from bouncing up and down. Shocks are velocity-sensitive, meaning they are smoother when dealing with light bumps and put up more resistance to big bumps. The primary purpose of the shock absorbers is to control spring and suspension movement and make sure tires maintain contact with the road.

Struts perform a damping function like shocks. Internally, a strut cartridge is similar to a shock. A strut assembly provides structural support for the vehicle suspension, supports the spring, holds the wheel and tire in the aligned position, and ensures the tire maintains contact with the road. Struts also bear much of the side load placed on a vehicle's suspension. As a result, strut assemblies affect riding comfort and handling as well as vehicle control, braking, steering, wheel alignment, and wear on other suspension components and the tires.

An independent front suspension allows each front wheel to travel up and down, with the spring and strut assembly bolted to the frame on one end, and a control arm or wishbone on the other end. A control arm is attached to the front of the vehicle near the centre at one end of the arm and the steering knuckle at the other. A wishbone does the same thing, except it attaches to the frame at two points, causing the piece to resemble a wishbone. The movement at connection points is softened and absorbed by bushings. The positioning of every component in independent front suspension systems is very important as the front wheels need to steer and maintain consistent alignment to provide safe vehicle operation.

 

 

Most modern vehicles have an independent suspension on the front and back, allowing each wheel to travel independently of the others. Some vehicles use a more basic beam axle. The only beam axles still being used in new vehicles are live axles. A live axle is one that supports part of the weight of a vehicle and drives the wheels connected to it. The problem with rear tires that don't move independently is they always keep the same angle relative to one-another, rather than relative to the road surface. This means less traction and less predictability in handling. This is one reason why an independent suspension is almost universally adopted by automobile manufacturers for the front and rear wheels on new vehicles.

If you are experiencing squeaks when going over bumps or dips, unusual clunking or rattling noises while driving on uneven roads or over potholes, oversteer traction problems, understeer traction problems, bump steer traction problems, excessive body roll, bottoming out, excessive bouncing when going over bumps, leaking shocks or struts, or the handling of your vehicle just does not feel right, have your suspension system inspected right away.

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