Together with the spring, the shock absorber forms the connecting link between the wheel suspension and the body. It reduces the vibrations of the vehicle spring, brakes it and compensates for road irregularities.
One of the main functions of the suspension is played by shock absorber springs. If they are stiff or large, this increases the rolling radius of the car, respectively, to reduce the discomfort of a rigid suspension, they can be made smaller or you can install softer ones. Our partners will help you choose the right products for your car model. Here, for example, is the article shocks for Jeep Wrangler. Every driver will find a set of shock absorbers that will greatly improve his/her riding experience.
Energy Conversion of the Shock Absorber
The shock absorber is basically an energy converter. It transforms the kinetic energy of the spring into heat through fluid friction. This happens as follows: The shock absorber piston is moved up and down in a cylinder filled with oil. Precisely defined valve passages in the damper piston and/or a bottom valve slow down the movement of the damper piston to such an extent that the spring oscillation is reduced right at the start.
If an obstacle is passed over, the spring is first called upon. During compression, it must not be impeded by the damper, which is compressed during this phase (compression stage). After the spring has compensated for the obstacle, the shock absorber must brake the spring as it relaxes with great force. During this process, it is pulled apart (rebound stage).
In the rebound stage, the vibration damper has a higher damping force than in the compression stage. During this damping work, the damper can heat up to 120 °C, depending on road conditions, speed driven and outside temperature. Good vibration dampers are designed to withstand this thermal load.
With defective shock absorbers the car has poor acceleration, problems with maneuverability, smooth running and other. The main task of shock absorbers is to keep the car’s wheel in constant contact with the road. Some shock absorbers are made too stiff, which leads to related problems.
You can make the suspension softer by replacing the shock absorbers. The most successful options for this are oil or gas-oil shock absorbers. If you want maximum suspension softness, it is better to choose an all-oil variant. If you do not know where to look for the right shock absorbers, Monroe and KYB brands have proven to be reliable, with a sufficiently large product line.
The Warning Signs of Worn Shocks and Struts
- “Nose flip” when braking – Do you feel the front end of your vehicle leaning quickly toward the ground when braking? This is called a “nose flip. It may indicate wear on the shock absorbers and struts. This phenomenon is dangerous because it may increase the braking distance.
- Rocking while driving – Excessive rocking when you hit a bump may be a sign that the shock absorbers and struts are not working effectively. The vehicle should level off after hitting a bump and stop rocking. Worn shock absorbers and struts cannot effectively dampen unevenness of the road surface and soften the impact of the bump.
- Car lurching in a corner – Feeling the car lurch in a corner is not only unpleasant, it’s also unsafe because you don’t feel like you’re in proper control of the car. When shock absorbers wear out, they lose their ability to control weight shift when cornering. It can also result in an increase in the force you need to apply to the steering wheel while cornering.
- Uneven tire wear – If the shocks and struts are worn, the vehicle can sway and the vehicle’s stability will be reduced. This swaying can also cause the tires to wear too quickly, including dents and tread wear in a wave pattern (when pieces of rubber are pounded out of the tire).
- Squatting backward under acceleration – Properly functioning shocks and struts stabilize the suspension shifting under acceleration. If the dampers and struts are already poorly functioning, the rear end of the car can sag a lot when you press the accelerator pedal sharply. The momentum during acceleration due to the forces of inertia causes the front of the car to lift. It causes motion sickness in passengers and unnecessary loading on the rear suspension components.
- Steering wheel vibration – A slight vibration in the steering wheel when driving on a bumpy road is normal. If the vibration remains on a level road, the shocks, struts, or steering stabilizer may be worn.
- Strange Sounds – If the shocks and struts are worn, you may hear a squeaking or knocking noise. This sound is caused by metal-to-metal contact when the shock absorber or strut is triggered by hitting a bump. In addition, such sounds can occur due to wear and tear of the fixing components of shock absorbers and struts.
- Fluid leakage on the outside of the shock absorber/strut – If you notice excess hydraulic fluid leaking from the shock absorbers or struts, it could be a sign of wear. If the seals are worn, the fluid required for the proper functioning of the shock absorbers and struts is leaking out.
Effects of Defective Shock Absorbers
Defective shock absorbers have the following negative effects:
- Heavy wear on the wheel suspension, wheel bearings and springs.
- Longer braking distance
- Higher risk of aquaplaning, earlier aquaplaning
- Higher risk of skidding in curves or during evasive maneuvers;
- Lack of grip on undulations or road crests
- Reduced ABS effectiveness
- Dazzling headlights
The Main Causes of Failure of Shock Absorbers
- Improper installation. It’s all over the place. They forget to tighten the nut, put the removable cups upside down, forget the dusters, grab the rod with pliers, etc.
- Smashed in smoke or missing dusters/bumpers – rod rusts/rusts and ends up running out of stuffing box.
- Breakdown (when levers in knot).
- Valve system wear (no leaks, there is resistance in the arms and the car is pumping).
Defective Shocks Increase Fuel Consumption and, as a Result, Volume of the Exhaust Gas
When a faulty shock absorber causes a car swinging, this requires additional energy. That’s why regular chassis maintenance will help you not only enjoy driving your car. It will also help you reduce exhaust emissions.
Replace struts, shocks, springs and sway bars with aftermarket parts specifically designed for speed and performance. A defective shock absorber should always be replaced in pairs per axle. The reason: a new shock absorber always has better performance than a used one. If the damping performance is different on the right or left, this can lead to unstable handling. Chassis equipped with gas pressure shock absorbers as standard can only ensure good roadholding and driving stability if equivalent gas pressure shock absorbers are also reinstalled when the shock absorbers are replaced.
We also recommend considering hydraulic and gas shock absorbers. Some manufacturers provide the ability to calculate the optimum weight on the computer, which allows to reduce fuel consumption.