Tires Tell a Story: Your Car's Suspension & Your Safety

When was the last time you took a good look at your tires? Your tires are really a part of your suspension system. They are actually the main reason you even have a suspension. The suspension system is not there to provide a smooth cushy ride. It is there for one purpose...to keep those tires in contact with the road. A smooth ride is a happy side result, and manufacturers do attempt to improve the ride by using different methodologies..but again, a suspension systems main purpose is to keep your wheels in contact with the ground.

Let us assume that you have kept the tire air pressure at a correct level all this time as we look into what the tires can tell us. Is the tread even across the width of the tire? There should be no low or high spots anywhere. If this is the case..and you have been running the tires for some time...it's a good bet that your suspension system is in good shape.

But let us say you notice the tire is worn more on one side than the other. This is an indication of incorrect wheel alignment. Your wheels can get out of alignment for a variety of reasons..so it's important that you take the vehicle in to a shop to have it checked out. The most common reason for misalignment is wear of the steering components. Notice that I said "steering" component..not a suspension component. If you ignore this problem, the tire will continue to wear abnormally until it suddenly deflates because you have worn through the tread and belts. And it can happen far faster than you might think. Abnormal wear..is WEAR ! You must stop it. This is no doubt a dangerous scenario you want to avoid.

Your steering components include the ball joints which allow the wheels to pivot left and right. The tie rods which attach the steering wheel and gear box to the wheels themselves. The ball joint assembly and tie rods are adjustable so that the tires can be positioned correctly for even wear. They should receive lubrication according to your owners manual schedule.

Let's talk about shocks. Bad shocks can cause the tires to develop little indentations. This is called cupping. And it is caused by that wheel actually bouncing and skidding just a tiny bit because the bounce is not being controlled by the shock. And the skidding accelerates wear and you can see what looks like scalloped areas all around the circumference of the tire. When you get right down to it, a shock absorber is rather misnamed. A more correct name would be spring bounce eliminator maybe. You can test your shocks by pushing down on the vehicle at a corner two or three times to get it moving in an up and down fashion. And on the last push down, release your grip and let the vehicle come to a stop. It should not bounce again. Should come to a smooth stop immediately. However, this is not a really good test. A number of things can affect a shock and how it responds. This test is a general rule of thumb sort of test. A better rule would be to replace all the shocks at one time around the 25,000 mile mark. The replacement shocks will offer a mileage quote for the mileage they will last. The longer the shock is good for, the more you will pay for it. I usually buy an original equipment type of shock. I figure I don't need nitrogen gas charged shocks with a one and a quarter inch shaft, to drive to work and pay twice as much for it. The shocks, springs and tires are the most critical parts of a suspension system. They control vehicle bounce, and thus, affect control. You cant steer if your wheel is not in contact with the road. Ever hydro plane? Your wheels are riding on a layer of water..and you have no control. And if your wheel is in the air, you are not going to be doing a lot of steering either.

The way the vehicle drives can also tell you some things about the condition of your suspension system. While driving take notice if the steering wheel seems tight and responsive. If you notice play or a sloppy response, it may be time for an inspection of your steering and suspension systems. Ball joints can and do wear out. They can even separate and allow the wheel to collapse to one side. Tie rods can also separate leaving you with one wheel steering. In states and cities where they perform annual inspections on your vehicle, this will certainly be one of the things the inspector will look at. Also while driving try to notice is the vehicle tends to wander..requiring constant correction. Improper tire inflation, misalignment, weak shocks, or worn steering components can all cause this. Best get it checked out.

Another often overlooked assembly of the suspension system, are the sway bars and pins. These are not crucial to the longevity of the tires so much as giving the vehicle better control in cornering. The pins which ties the sway bare to the control arms use thick rubber or neoprene bushings...which wear out over time like everything else.

Finally we come to the springs. They have no moving parts and usually last for the lifetime of the vehicle. You will know if you break one as the car will usually sag on that corner. And you may notice a very rough ride. It will need to be replaced immediately should this happen.