Coil springs are used in just about every vehicle on the road. They are the most popular method to connect the vehicle body to the axles and provide a comfortable ride for the occupants. Simple in design (a treated metal rod wound into a coil) they are quite robust and rarely give trouble. They have taken over from leaf springs and even strut suspension uses a coil spring.
While the shape of the spring never changes, the height, thickness, no of coils, colour and spring tension does. Coils have a variable rate which means the spring rate increases as the coil compresses. This provides better load carrying and ride comfort than a linear rate spring. Spring rate is how much force it takes to compress a spring 1mm in metric (kg/mm) or an inch (lbs/inch) in the old imperial system.
Popular Questions Asked
How do I know if my coil springs are worn out?
There are a few things you can look for. Sagging body on one side, crushed or missing bump stop and handling/ride comfort changed. A quick visual inspection and comparing the springs (driver & passenger sides) will usually show up the issue.
How much does it cost to replace coil springs?
This is hard to quantify as some springs are easy to change where others can be more involved. Also the cost of the springs may vary greatly. Always replace both springs, not just the sagged one. Rough rule of thumb $500 if getting it done by a professional. Half of this cost ($250) is the price of the springs.
You can change them yourself just be aware some springs require a spring compressor tool to remove and install them. These can be expensive to buy for a one off job so do your homework before starting on it. Remember a compressed spring is dangerous so get the right tool for the job.
Will new coil springs improve ride?
Changing old or worn springs will definitely improve the ride quality. If the spring was worn or damaged check the shock absorber or strut as well. The reason is they will be working harder to cope with the failing spring. If they need changing as well, please change both sides. It is more expensive but well worth the investment.
Changing springs to lower or raise ride heights is extremely popular. Depending how high or low you go always check shock absorber or strut travel matches your new springs otherwise you won't get the full benefit of the spring changes. Springs and shocks work as a team like Batman and Robin so if modifying one always consider the impact to the other.