What suspension components are most likely to fail?
The suspension on your vehicle was designed to give you the best combination of comfort, reliability, and performance. Depending on the manufacturer, the suspension can be fairly simple or it can be very complex. Your suspension can consist of a control arm or two, and up to several different strut rods and track arms. With all of these possible parts, which are consistently moving while the vehicle is in motion, you can have any number of failures. Every vehicle out there is a little different from the next, so they all will be a little different when it comes to failing parts. With that being said, there is one part that is common to all vehicles that tends to be the most common failure.
All vehicles come with some sort of suspension strut assembly or shock absorber. Both of these are designed to do the same thing, though they have a slightly different mounting. Their purpose is to control the oscillation, or the up and down movement, of the suspension springs. What this means is that, as you go over bumps and imperfections in the road, the wheels move up and down on the suspension. The up and down movement comes from the suspension springs allowing the suspension to move.
If there were no shocks or struts installed, the spring would push back on the suspension rapidly causing the vehicle to start to bounce. Once the vehicle starts to bounce, it would become very dangerous. The shocks and struts control this movement. They have an internal piston that travels within a cylinder, which is filled with pressurized gas and fluid. That internal pressure fights against the pistons movement making it hard for the shock or strut to expand or retract rapidly. This resistance controls the movement of the suspension spring. It basically slows down the bouncing and causes it to stop within about two bounces when it is functioning properly.
Being that the shocks and struts are constantly moving as the vehicle is going down the road, they tend to wear out the fastest. The most common failure of the shocks is the piston seal. This seal fails from constant movement and ends up allowing the fluid to leak from the cylinder and it allows the gas to escape. Once this occurs the vehicle begins to bounce more which causes the tires to wear prematurely and can cause other suspension parts to fail prematurely.
It can also fail and begin to bind internally. If this occurs, then the piston can no longer move within the cylinder. When this happens, it causes there to not be movement in the suspension, which causes the vehicle to ride extremely rough. When either of these instances occur the shocks or struts need to be replaced. When they are replaced they must be replaced in pairs to ensure that the suspension is balanced.
Your shocks or struts will be the most common suspension part that will need to be changed. Over time your vehicle will also need bushings or ball joints, but these do not typically fail until they age and begin to rot.
There are other scenarios that will change which parts fail. Oil leaks will cause rubber parts of the suspension to wear prematurely. Modifying your vehicle by lifting or lowering the suspension, as well as installing larger wheels and tires will also cause suspension and steering components to fail much faster than they normally would. The best way that you can ensure that your suspension components do not fail prematurely is to inspect them regularly and to be easy on your vehicle when driving over large dips and bumps in the road. Having a certified mechanic, like one from YourMechanic, can help you to identify suspension problems before they occur.