A shock absorber or damper is a mechanical or hydraulic device used to absorb and damp shock impulses. This is done by converting the kinetic energy of the shock into another form of energy (typically heat), which is then dissipated. Most shock absorbers are some sort of dashpot (a damper that resists motion by viscous friction).
Along with smoothening out bumps and vibrations, the key role of the shock absorber is to ensure that the vehicle’s tyres remain in contact with the road surface at all times, which ensures the safest control and braking response from your car.
Shock absorbers essentially do two things. Shock absorbers not only control the movement of springs and suspension but also keep your tires in contact with the ground at all times. At rest or in motion, the bottom of your tires is the only part of your vehicle that comes into contact with the road.
Any time that a tyre’s contact with the ground is broken or reduced, your ability to drive, steer and brake is severely compromised.
The shock absorbers dampen the movement of the springs by converting the spring’s kinetic energy into thermal (heat) energy. Shock absorbers are oil-filled cylinders. When your vehicle’s suspension moves, a piston moves up and down through the oil-filled cylinder.
Firstly, a little bit of science. Shock absorbers work by taking the kinetic energy (movement) of your suspension and converting it to thermal energy (heat) that is then dissipated into the atmosphere through the mechanism of heat exchange. But it’s nowhere near as complicated as it may sound.
As mentioned, shock absorbers are basically oil pumps. A piston is attached to the end of a piston rod and works against hydraulic fluid in the pressure tube. As the suspension travels up and down, the hydraulic fluid is forced through orifices (tiny holes) inside the piston.
Because the orifices only allow a small amount of fluid through the piston, the piston is slowed which in turn slows down spring and suspension movement.
Shock absorbers automatically adjust to road conditions because the faster the suspension moves, the more resistance they provide.
Following are the different types of shock absorbers:
Hydraulic type shock absorbers are now used on all passenger cars. They increase resistance to the spring action by forcing a fluid through check valves and small holes.
Double-acting shock absorbers offer resistance both during compression and rebound of the springs.
A single-acting shock absorber offers resistance only on the rebound.
The friction-type shock absorbers have almost become obsolete due to their non-predictable damping characteristics.
The lever-type shock absorber is of indirect-acting type. It is bolted to the chassis through a lever and link. As the axle moves up and down, a double piston arrangement forces the oil through a valve.
Telescopic type shock absorber is of direct-acting type. It is mounted between the axle and the frame.
A simplified diagram of the telescopic shock absorber. Its upper eye is attached to the axle and the lower eye to the chassis frame. A two-way valve A is attached to a rod G. Another two-way valve B is connected to the lower end of cylinder C.
The fluid is in the space above and below valve A, and also in the annular space between cylinder C and tube D, which is connected to the space below valve B. The head J has a gland H. Any fluid scrapped off by the rod G is brought down into the annular space through the inclined passage.
A twin-tube shock absorber consists of an inner and outer cylinder. The inner cylinder contains oil and the piston rod is connected to the piston valve. Whereas the outer cylinder acts as a reservoir and has a low-pressure gas. The flow of oil from one chamber to another is controlled by a base valve.
As the wheel moves up and down, so does the piston rod. The piston valve and base valve confirm the compression and rebound of the absorber. They measure how fast the oil flows back and forth. Vibration and shock are similarly absorbed by low-pressure gas. This gas acts like a balloon and absorbs vibrations.
These are high-pressure gas shocks having a pressure tube. This pressure tube consists of two pistons, a dividing piston, and a working piston. The installed pistons and rods are similar in design to twin-tube shocks.
A mono-tube shock absorber is mounted upside down or right side up and will work either way. Considering its flexibility, mono-tube shocks with springs are an important component to support the weight of the vehicle.
A mono-tube shock absorber does not have a base valve. The mono-tube shock has a greater surface area and carrying capacity. These are well known because the high amount of oil helps to dissipate heat much faster and reduces fading.
Spool valve dampers are characterized by the use of hollow cylindrical sleeves with machined-in oil passages as opposed to traditional conventional flexible discs or shims. Spool valving can be applied with monotube, twin-tube, and/or position-sensitive packaging, and is compatible with electronic control.
Primary among benefits cited in Multimatic’s 2010 patent filing is the elimination of performance ambiguity associated with flexible shims, resulting in mathematically predictable, repeatable, and robust pressure-flow characteristics.
Shock absorbers are critical safety components that can affect tire wear, stability, braking, vibration, driver comfort, and the life of other steering and suspension parts. Shocks work with a commercial truck’s suspension system to maintain tire-to-road contact by controlling spring movement.
4 Symptoms of Worn or Failing Shock Absorbers
The short answer is no – you should not drive a car with a broken suspension. Regardless of whether it’s a broken coil spring or a broken shock absorber, you cannot drive a vehicle that has an element of the suspension that is broken.
On average, if your car has been “babied,” you can expect your shocks/struts to last about 10 years. If you have really used your car as a workhorse, 5 years is probably all you can expect. This means that for the average driver, 7 or 8 years is the maximum life expectancy of most shocks and struts.
Shock absorbers are small oil pumps with a piston inside. They’re filled with oil and usually have a rod that goes through the top of the shock. The top of the shock has a seal that stops any leakage, but this can get damaged, and the oil leaks out over time.
Unusual noises – When shocks and struts are worn out you may hear a clunking or knocking sound. This sound is caused by metal-to-metal contact when the shock or strut bottoms out when hitting a bump. In addition, these noises could be a result of worn shock or strut mounting components.
Bad shocks also can affect steering control and cause uneven tire wear. Because car shocks wear out gradually, you might not notice because you get used to looser, bouncier ride quality, much like you get used to longer stopping distances as brake pads on your car wear out.
Like all other automobile parts and systems, shocks and struts have a specific maintenance schedule. Auto repair experts say that generally they should be replaced between every 50,000 to 100,000 miles, depending on how much wear and tear they have received.
Your shock absorbers work in pairs, so ideally, replacing both of them should be carried out at the same time. However, if one has broken, or is severely damaged, you could consider replacing only the damaged side.
The Warning Signs of Worn Shocks and Struts
Loading more weight into a vehicle than it is rated to carry can cause the struts supporting the car to bend. However, even if a car is near, but not beyond, its maximum payload, potholes or other flaws in the road can bounce the vehicle. This bouncing can cause weight shifts inside the vehicle that can bend struts.
In fact, most modern vehicles have struts on the front axle and shocks on the rear axle. You might have struts on both axles, but it is rare to have only shocks.
To replace the shocks on the same axle, on average, it will cost you between $250 and $600 for parts, while labor costs will be somewhere between $150 and $350.
Gas-charged shocks provide a sportier ride. must compress before the oil can be forced through the valve. Hydraulic shocks give a softer and smoother ride. is increased at a slower in the hydraulic shocks which produce the softer feel.
Shocks are simply tubes filled with hydraulic oil and attached to a piston, a device that allows the shock to release small amounts of hydraulic oil under great pressure to relieve the vehicle’s bouncing movement.
The shock absorbers dampen the movement of the springs by converting the spring’s kinetic energy into thermal (heat) energy. This thermal energy has then degenerated in hydraulic fluid. Shock absorbers are oil-filled cylinders.
Shock absorbers are critical safety components that can affect tire wear, stability, braking, vibration, driver comfort, and the life of other steering and suspension parts. Shocks work with a commercial truck’s suspension system to maintain tire-to-road contact by controlling spring movement.
Shock absorbers and dampers are generally made of high-strength steel to handle the pressures from the internal hydraulic forces. Elastomeric seals prevent the fluid from leaking out of the cylinder, and special plating and coatings keep the units protected from harsh operating environments.
Following are the different types of shock absorbers:
More accurately called dampers, “shocks” damp excessive motion, keeping the vehicle’s body from bouncing down the road.
A broken shock absorber will result in your car bouncing around, as well as excessive rolling, squatting, and diving. In other words, it won’t be comfortable. Plus, your car will be harder to control, especially at high speeds.
As far as shocks also referred to as the shock absorbers, are a key component of the suspension system. They control the impact and rebound movement of your vehicle’s springs and suspension; they ensure that the vehicle’s tires remain in contact with the road surface at all times. ultimately, they absorb energy.
On average, if your car has been “babied,” you can expect your shocks/struts to last about 10 years. If you have really used your car as a workhorse, 5 years is probably all you can expect. This means that for the average driver, 7 or 8 years is the maximum life expectancy of most shocks and struts.
Not every shock absorber problem can be repaired. Parts that you can replace individually include mounts, shock absorber bushings, seals, pistons, and compression oil. As a rule of thumb, you should only consider shock absorber repair if the existing shocks have not done more than 35 000 miles or slightly more.
The short answer is no – you should not drive a car with a broken suspension. Regardless of whether it’s a broken coil spring or a broken shock absorber, you cannot drive a vehicle that has an element of the suspension that is broken.
