When every road becomes the bumpiest road in the world, maybe it is time to get new struts. Most manufacturers recommend replacing struts and shocks every 50K to 70K miles. Does your vehicle nose dive when you step on the brakes? You can significantly reduce nose diving by replacing your struts/shocks. The shocks and/or struts in your car perform two functions. They dampen spring movements and aid in ride control.
Shocks, struts or even coil springs are produced by various trustworthy, top brands for all types of vehicles. No matter the year, brand or model, you can find the strut that goes with your car here at eBay.
Struts help improve a vehicle's handling while turning or braking. At the same time, struts are an important part in the overall comfort level for everybody inside the vehicle. Unlike a shock, which cushions the vehicle from bouncing up and down too much, a strut gives side-to-side stability.
Shocks vs Struts
What do shocks do?
The main role of the shock absorber is to control spring and suspension movement. Although it is widely believed that they also support the weight of the car it isn’t so. Shock absorbers change the kinetic energy of the suspension and create heat which is drained through the hydraulic fluid.
Shock absorbers can be seen as mini oil pumps. As the suspension moves up and down, the hydraulic liquid is pushed through orifices inside the piston which helps to slow down the piston causing the spring and the suspension to slow down too.
How much a shock absorber can take depends mostly on the suspension and the size and number of these aforementioned orifices in the piston. All modern shock absorbers are speed sensitive hydraulic damping devices - meaning the faster the suspension moves, the more resistance the shock absorber provides.
Because of this feature, shock absorbers adjust to road conditions helping shock absorbers reduce:
- Roll or sway
- Brake dive and Acceleration squat
A strut is an essential structural part of a suspension. Struts perform two main jobs. First, struts perform a damping function like shock absorbers. Struts also perform a second job. Unlike shock absorbers, struts provide structural support for the vehicle suspension, support the spring, and hold the tire in an aligned position.
Since struts are lighter and smaller than shock absorbers, they take less space in the typical suspension systems. Normally, struts are placed where the upper control arm and the upper joint ball usually are in these typical suspension systems.
Additionally, they take much of the side load placed on the vehicle's suspension. As a result, struts have impact on riding comfort and handling as well as vehicle control, braking, wheel alignment and wear on other suspension.
You need to understand some of the terms associated with struts, in order to really get them. Here are some important terms you should get familiar with:
Term and Meaning
- Stroke: The stroke is a measure of the strut that fits into the spring leg
- Extended Length: The total length of the strut, including the spring leg and the shock absorber
- Shock Absorber: The shock absorber fits into the spring leg and helps dampen the shock from the road
- Coil: In a coilover strut, the coil is the spring that fits over the shock absorber and helps further reduce shock
- Spring Leg: Contains the cushions and springs that make up the main body of the shock absorber
Even though most struts work based on similar principles, they function in different ways to obtain the same result. The above terms might give you some insight into struts in order to help you choose the right strut for your needs.
Types of Struts
The three principal types of struts are coilover, gas, and pneumatic. The three of them work on the same goal of reducing the shock of over-the-road travel by diminishing the shock produced through springs, oil, and gas. The table below details all three types of struts:
Strut Type and Description
- Coilover Strut: Coilover, or MacPherson struts, are shock absorbers with a spring encircling the top of the strut for increased dampening
- Gas Charged Strut: Also known as a gas strut, these struts are fitted with oil like a pneumatic strut, but also have gas in the strut, the gas improves the performance of the strut by reducing foaming
- Pneumatic Strut: Contains oil that creates pressure within the strut, dampening the shock from diving; also called a hydraulic strut
You should check or replace gas-charged struts in pairs to prevent twisting caused by uneven loading. When replacing struts, it is also essential that the same type of struts is used to replace worn or damaged ones.
Strut Placement on Vehicle
In addition to the different types of struts, there are also struts for different parts of the suspension system. This includes the front and rear, as well as the left and right side of the vehicle.
The strut helps dampen the shock produced from braking, especially the forces produced from sudden stops when they are in the front. On the other hand, a rear strut helps keep the back end of the car from bottoming out from a high rate of acceleration.
A left-side strut helps dampen the shock produced when turning left; also, keeps the vehicle from rolling too much in a turn and the right-side strut helps with vehicle roll in a turn; dampens the shock produced from right turns.
Standard Strut Sizes
Remove the current strut to determine the correct strut size needed. This task could be kind of difficult for DIYers; however, you can just get a complete strut assembly that will eliminate the issue of disassembling all its components, which is the trickiest part of the process.
When getting new struts, you should note if the strut is a brand name or a generic part. Also, you should copy any numbering or lettering printed on them. Also, you should measure the strut from the top channel to the bottom of the strut mount with a tape measure. Then, you must extend the shock all the way by pulling on the tube body and measure this length from the top shaft to the strut mounting bracket.
Then, you can take their measurements, any lettering or numbering on the strut and use them while shopping eBay online to find replacements. This information will allow you to choose the correct strut for the vehicle if you want to buy them online. The following sections contain common sizes for coilover, gas, and pneumatic struts.
Coilover Struts or MacPherson Struts
The following table contains both the stroke and extended lengths of some coilover struts.
Stroke Length / Extended Length
- 60 millimeters / 195 millimeters
- 160 millimeters / 405 millimeters
- 210 millimeters / 500 millimeters
- 260 millimeters / 605 millimeters
- 300 millimeters / 700 millimeters
- 360 millimeters / 795 millimeters
When shopping for coilover struts, be sure to get the correct size strut for your vehicle.
The following table contains the diameter of both the shaft and tube of gas and pneumatic struts.
Shaft Size / Tube Size
- 6 millimeters / 15 millimeters
- 8 millimeters / 18 millimeters
- 10 millimeters / 21 millimeters
- 14 millimeters / 28 millimeters
When replacing struts, make sure to purchase the right size struts. The wrong size strut can cause a failure with the suspension and damage the vehicle and the strut.
Popular Strut Brands
Popular strut manufacturers range from Monroe, to Bilstein, to ACDelco. The list below includes seven top strut brands:
Buy Struts Online with Confidence
Before deciding on a specific product, carefully read the details in each product listing.
Details should include:
- Delivery costs.
- If the seller provides a money-back guarantee, and other terms of the sale.
- Know the correct size and type.
When replacing struts, make sure to measure them for size, if possible, in millimeters. This includes both the strut stroke length and the extended strut length. You should also note any numbering or lettering printed on the strut.
But before buying struts, you must remember to investigate the available options and learn about the different types of struts on eBay.
Common Struts Q&A
Do all vehicles have struts?
Not all cars and trucks have struts; many suspension designs use separate springs and shock absorbers, with the shocks supporting no weight. Also, some cars use struts only on one pair of wheels, usually the fronts, while the other pair employs a different design using separate springs and shocks. When a car has struts on the front wheels only they are usually MacPherson struts, which are struts that are also considered part of the steering system because the wheels are designed to pivot around them.
Why do some vehicles use struts while others have separate springs and shocks?
This comes down to initial cost (advantage: struts) and handling and performance (advantage: certain suspension designs without struts ... usually). But there are exceptions to these patterns; for example, most sports cars employ what’s called a “double wishbone” suspension, which uses shock absorbers rather than struts, but the Porsche 911 for example, uses struts.
How can I maintain the struts in my car?
If your car has struts or shock absorbers you will want to have them inspected periodically for leaks or other damage. One difference is that when they do wear out, struts are more expensive to replace, but there’s nothing a driver can do about that. Regardless of what suspension system your car has, be sure to have it inspected regularly.
Damaged, leaking, or worn struts should be replaced as soon as possible. This helps prevent strut failure and keeps vital vehicle components, such as tires, wheels, and the suspension, from wearing out too quickly.