Driving with a broken coil spring can be a nerve-wracking experience, with your car bouncing and making strange noises. But is it safe to continue driving?
The answer is no; it is unsafe to keep driving with a broken coil spring. Read on to find out why!
First, you should understand the importance of a coil spring before you can get to grips with how dangerous it is to drive with one broken.
What Is the Job of a Coil Spring
Surprisingly enough a cars coil spring has 6 main functions that include:
- Load-bearing support – The primary function of a coil spring is to support the vehicle’s weight, which includes the chassis, body, engine, and passengers. It helps maintain the appropriate ride height regardless of the weight (if inside the vehicle’s max load) and prevents excessive sagging or bottoming out.
- Shock absorption – Coil springs work in conjunction with shock absorbers or struts to dampen the impact and vibrations caused by uneven road surfaces, bumps, and potholes. They absorb and distribute the energy from these bumps, reducing the effects and chances of damaging other car components.
- Control and stability – Coil springs play a vital role in maintaining the stability and control of the vehicle during acceleration, braking, and cornering. They help keep the tires in contact with the road surface, which improves traction and handling.
- Ride comfort – By absorbing road imperfections and minimizing jolts and vibrations, coil springs contribute to a smoother, comfier ride for the driver and passengers.
- Weight distribution – Coil springs evenly distribute the vehicle across all four wheels. This helps ensure balanced handling and prevents excessive weight transfer during acceleration, braking, and cornering.
- Alignment – As a vehicle compresses over bumps in the road, the suspension alignment angles change. The coil springs keep the ride height consistent, which helps maintain the correct suspension geometry. When the ride height changes, this directly impacts wheel alignment angles such as camber, caster, and toe.
Is It Safe to Drive With a Broken Coil Spring?
It is not safe to drive with a broken coil spring! Driving with a broken coil spring is a safety concern for multiple reasons. You should not drive the vehicle and have it recovered to a suitable place for repair.
What happens if you drive with a broken coil spring?
As the coil springs’ job is to absorb any bumps in the road and return the car to its normal ride height, when a spring breaks effectively, one side of the vehicle is sagging, sitting much lower than it should. When you try to drive, the car will no longer go straight or steer correctly. If you try turning the wheel, you will hear and feel the coil spring catching in the spring pan, and the car can pull quite violently to one side. This will also cause damage to other suspension components, such as the shock absorber and top mount.
You may also hear a ‘twanging or knocking noise‘ as the broken half of the spring moves in the spring pan. This is another problem with coil springs as they are kept under such high tension to keep them in the spring pan. When a spring breaks, the spring doesn’t stay in its location between the strut top mount and the bottom of the spring pan. So the spring can fall out and get trapped between the pan and the tire. Yup, you guessed it, the sharp edge of the broken spring can and does stab the inside of the tire resulting in a blowout. I’m sure you know you can not get very far on a flat tire!
What Causes a Coil Spring to Break?
- Rust or corrosion – Coil springs are exposed to water, oil, and contaminants as you drive. All contribute to accelerating rust and corrosion set into the metal of the coil spring. A slightly weaker area of a coil spring will break from just a nasty pothole in the road. But know that it was probably a weak coil spring in the first place, regardless of the bump.
- Metal fatigue – Metal fatigue typically happens due to the age of the coil springs. As they age, they become less ‘springy’, eventually weakening enough in one area that the spring will snap.
- Overloading – A car is designed to have a maximum load and towing limit supported by the coil springs. Regularly exceeding weight limits will weaken the coil springs quickly.
- Impact damage – Any severe impacts that cause damage to suspension components will put added pressure on the strut and coil spring. If there are any age-related weaker areas in the coil spring, they will fail.
- Manufacturing defects – Manufacturing defects are extremely rare, but like with all things, it occasionally happens, especially with inferior aftermarket replacement parts. A typical problem with aftermarket parts is you might get one spring holding the car at the incorrect height, which puts added pressure on the other spring, causing a failure.
Moving the Car With a Broken Coil Spring
This is not always possible, but if the coil spring has completely snapped in half and is rattling in the spring pan, you can sometimes completely unwind the coil from the strut and remove it. If the spring is not loose, do not attempt this; even though the coil spring has snapped, they are kept under immense pressure. The car will drive and handle like a boat, but moving it to a safe place may be possible. Do not attempt to drive any further than a few yards. You will cause damage to the shock absorber by driving with no coil spring in place!
Bottom Line
To answer, can you drive with a broken coil spring? The answer is no; you should avoid driving. Broken coil springs can be hazardous. Not only can the suspension lock up if the coil spring gets jammed, but the damaged part of the spring can cause the tire to shred. Even moving the car a few feet is risky, so you should have the vehicle recovered to a suitable repair place.
