Tire Topics - How To Inspect Your Tires
What should I look for when inspecting my tires?
In addition to performing regular maintenance, you must also keep an eye out for potential problems that might affect your tires. Regular inspections can help you prevent tire trouble, and keep you rolling safely down the road. When inspecting your tires, look for:
1. Uneven tread wear. This can include more wear on one tread edge than the other, a rippled pattern of high and low wear, or exposed steel wire. Uneven wear can be caused by problems such as under inflation, misalignment and improper balancing.
2. Shallow tread. Bald tires tend to skid and slide on the pavement, and are more likely to be damaged by potholes and other road hazards. The tread on your tire should be at least 1/16 of an inch deep. If it isn’t, the tire must be replaced. To help you see tread problems, tires have built-in “tread wear indicators.” These are narrow bars of smooth rubber that run across the tread: When the tread is even with the bars, it is worn down to the minimum level and must be replaced immediately. You can also perform a simple test using a US penny. Put the edge of the coin into the tread, with Lincoln going in head first. If the top of Lincoln’s head is covered by tread, that’s good. If the top of his head is entirely visible, it’s time to replace the tire.
3. Troublemakers. Check for small stones, pieces of glass, bits of metal and other foreign objects that might be wedged into the tread, and carefully pick them out. They can cause serious problems if they are pushed farther into your tire as you drive.
4. Damaged areas. Cracks, cuts, splits, punctures, holes and bulges in the tread or on the sides of the tire can indicate serious problems, and the tire may need to be replaced.
5. Slow leaks. Tires lose some air pressure (about 1-2 psi) over the course of a month or so, but if you find that you have to add air every few days, have the tire, wheel and valve checked—and if necessary, repair or replace the tire.
6. Valve caps. Those little caps on your tire’s valve stem keep moisture and dirt out, so make sure they are on all your tires. Also, when you have a tire replaced, have a new valve stem assembly installed at the same time.
Driving on a damaged tire can be dangerous. If you see something you’re not sure about during your inspection, have it examined by our tire experts. Any time you see damage to a tire, don’t drive on it—use a spare if you need to go somewhere. And finally, pay attention to the “feel” of your tires as you drive. A rough ride may indicate tire damage or excessive wear. If you notice vibrations or other disturbances while driving, and/or you suspect possible damage to your tire or vehicle, immediately reduce speed, drive with caution until you can safely pull off the road and stop, and inspect your tires. If a tire is damaged, deflate it and replace it with your spare. If you do not see any tire damage and cannot identify the source of the vibration, have the vehicle towed to a mechanic or tire dealer for a thorough inspection.
Can I mount my own tires?
Tire mounting can be dangerous and should be done only by trained persons using proper tools and procedures. Serious injury or death may result from explosion of tire/rim assembly due to improper mounting. Always have your dealer mount your tires on rims. If you are not thoroughly familiar with Rubber Manufacturers Association mounting procedures, never attempt to mount tires.
How do I check for proper wheel alignment?
Proper alignment ensures that your vehicle handles correctly and will help increase the life and performance of your tires. Failure to keep your vehicle's wheels properly aligned can result in:
- excessive tire wear
- irreparable tire damage
- excessive fuel consumption and unsafe handling
Tires should be checked monthly for signs of irregular wear in both tread and shoulder areas. Irregular wear may indicate under-inflation or tire damage, or the need for wheel alignment or suspension repairs. A wheel alignment is also strongly recommended when a replacement set of tires is fitted to a car.
Three key elements involved in wheel alignment that affect the vehicle's performance are:
1. Camber - The angle between a perpendicular line and a line drawn through the centerline of the tire when the vehicle is viewed from the front. Camber helps distribute the vehicle's weight across the tire contact patch during cornering for reduced tread wear and is used to fine tune a vehicle's handling characteristics. Incorrect camber causes uneven tire wear, poor steering and vehicle stability, and vehicle pull.
2. Caster - The angle between a vertical line and a line drawn through the center of the ball joints (steering axis) when the vehicle is viewed from the side. An improper caster can cause hard steering, increased road shock, reduced straight line stability and cause the vehicle to pull one side or the other. A positive caster helps maintain directional control of the vehicle, helping to return the vehicle to a straight position when cornering, and helps compensate for the crown on a road. Most cars are engineered with a positive caster
3. Toe - The angle between a line through the center of a vehicle and lines drawn through the centerlines of the tires when the vehicle is viewed from above. Toe alignment is the most critical to tire wear. Incorrect toe results in rapid and uneven wear.