Your suspension system works to keep your ride smooth, your vehicle protected and your steering under control. A strut is a compound suspension component that plays an integral role in the system, doing many jobs at once. A blown strut, therefore, can make for a drive that’s not only uncomfortable but also unsafe.
It’s important to get to know the signs of a failing or bad strut — which should typically be replaced in pairs — because chances are good that if you think your struts are going bad, they probably are.
Bump in the Trunk
The classic sign of a bad strut is the exaggerated bounce of your chassis. Struts are comprised of both shocks and springs, so their force works in both directions, keeping the vehicle ride height off the ground and pushing the wheels to make contact with the road when you drive over bumps. If this stabilizing force is weakened in the case of a blown strut, the jouncing caused by uneven terrain won’t be controlled smoothly, and you’ll feel it in your ride.
You can check for this issue while your car is parked by physically pushing on the corners and observing to see if there are two or more full rebounds. If you see excessive jouncing, the struts likely need to be replaced.
Irregular Tire Wear
When the above happens, your tires may momentarily lose contact with the road at fast speeds, causing irregular tire wear. The weight and velocity of the car will force little chunks out of the rubber off the tires and result in wear called “cupping.” This can also be caused by other suspension and alignment issues, but bad struts are a common cause.
Uneven Ride Height
Since struts are responsible for maintaining even ride height, bad struts may be immediately apparent when you look at how your vehicle is sitting. Does it look like one end or corner is sagging? This may be due to a bad strut or pair of struts.
Likewise, as you’re driving, pay attention to what happens when you brake, accelerate, turn and go over bumps. Do you notice the front of the car doing a nose dive? This could be due to the struts not holding up their end of the bargain and failing to support the chassis as they should.
With many car woes, a noise will often alert you to the fact that something is wrong. Bad struts may allow the chassis to bottom out as you pass over bumps, which can cause a clanging noise. You may also notice creaking noises and find it difficult to turn or brake — a clear sign of a worn strut bearing and an unsafe situation.
Diagnosing a Blown Strut
To inspect your struts for signs of wear, look for leaking or seepage. Struts are filled with hydraulic oil, and the interior seals are known to fail over time, which can result in dripping under the vehicle or a light coat of oil around the shock. Look for outright bent or broken shocks and springs too.
Remember that if you choose to remove and replace your own struts, you’ll need to follow safe procedures because the job requires professional tools and expertise. Otherwise, diagnosing blown struts is always a great first step to take before you bring your vehicle to a trusted mechanic.
Check out all the strut products available on NAPA Online, or trust one of our 17,000 NAPA AutoCare locations for routine maintenance and repairs. For more information on assessing a blown strut, chat with a knowledgeable expert at your local NAPA AUTO PARTS store.
Featured image courtesy of Flickr.
Blair Lampe is a New York-based professional mechanic, blogger, theater technician, and speechwriter. In her downtime she enjoys backpacking wherever her boots will carry her, rock climbing, experimental theatre, a crisp rosé , and showering love on her 2001 Sierra truck.