AccessMyLibrary provides FREE access to millions of articles from top publications available through your library.
That's the way the car bounces
When you read about the advancements that are taking place in ride control technology today, it's easy to lose sight of the fundamentals in this business.
Springs, shocks and struts are not about to become obsolete just because Nissan introduced the world's first production active suspension on the Infinity Q45. Ford made the same claim several years ago when it put a computerized air ride suspension under the Lincoln.
Some suspensions today do incorporate a lot of high-tech ride control gimmicks, but the costs are high, too. So the really exotic hardware will likely be limited to the $30,000+ luxury sedans and sports coupes for the foreseeable future. The vast majority of your customers will still be carried along on conventional springs, shocks and struts - which means you'd better pay attention to the basics if you're going to get your share of replacement sales.
With that in mind, let's look at each of these basic ride control components to better understand their roles.
If you're into the high-tech mode of thinking, think of springs as flexible antigravity devices. After all, the springs keep the chassis suspended in midair. Without their steady resistance to the downward force of gravity, the chassis would sit like a low-rider and there'd be no suspension. So springs are a necessary and much appreciated component in the ride control system.
As springs age, they sag. The constant load they bear leads to creep within the molecular structure of the metal. Over time, the spring weakens and begins to lose height (coil spring) or arch (leaf spring). As the spring settles, ride height decreases - which upsets primarily camber and caster wheel alignment.
That's why ride height must always be checked prior to realigning the wheels. More than an inch of sag usually means it's time for new springs.
Spring sag also reduces the suspension's ability to support its normal load. This, …