© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Publisher The Goodheart-Willcox Co., Inc. Tinley Park, Illinois by Russell Krick

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only  Tires  Wheels  Valve stems and cores  Lug nuts, studs, and bolts  Wheel weights  Hub and wheel bearing assemblies

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only  Tires perform two basic functions:  act as a soft cushion between the road and the metal wheel  provide adequate traction (friction) with the road surface

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Tire Types  Pneumatic  filled with air  internal air pressure pushes out on the inside of the tire to support the vehicle  Tubeless tire  does not use an inner tube  tire and wheel form an airtight unit  Tube-type tire  uses an inner tube to hold air pressure

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Tubeless Tire

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Parts of a Tire

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Tire Rolling Resistance  Measurement of the amount of friction produced as the tire operates on the road surface  High rolling resistance increases fuel consumption and wear  Rolling resistance is reduced by higher inflation pressure, tire design, and a lighter vehicle

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Tire Construction  There are many design variations:  different numbers of plies may be used  plies may run at different angles  different materials may be used  Three types of tires used on automobiles:  bias ply tire  belted bias tire  radial tire

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Bias Ply Tire  Plies run on an angle from bead to bead  The angle is reversed from ply to ply  Does not use belts  The body of the tire flexes easily  Provides a smooth ride  The plies and tread are weakest  reduces traction at high speeds  increases rolling resistance

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Bias Ply Tire

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Belted Bias Tire  Bias tire with belts added to increase tread stiffness  The belts lie under the tread area only  Two stabilizer belts and two or more plies improve tire performance  provides a smooth ride and good traction  reduces rolling resistance

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Belted Bias Tire

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Radial Ply Tire  Plies run straight across from bead to bead  Stabilizer belts lie beneath the tread  The belts can be made of steel, flexten, fiberglass, or other materials

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Radial Ply Tire  Has a very flexible sidewall and a stiff tread  provides a very stable footprint  improves safety, cornering, braking, and wear  may produce a harsher ride at low speeds

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Radial Ply Tire

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Tire Sidewall Markings

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Alpha-numeric– Uses letters and numbers to denote tire size in inches and load-carrying capacity in pounds Tire Size

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Tire Size P-metric– Uses metric values and international standards

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Points of Measurement

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Aspect Ratio Height-to-width ratio of a tire

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Maximum Load Rating  Amount of weight the tire can carry at the recommended inflation pressure  Printed on the sidewall  P-metric:  given in kilograms and pounds  Alpha-numeric:  indicated by a letter, such as B, C, or D

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Maximum Inflation Pressure  Highest air pressure that should be pumped into the tire  Many tires have a maximum recommended pressure of 32 to 40 psi (220 to 275 kPa)

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Tread Plies  Number of plies and ply rating:  2-ply  2-ply with a 4-ply rating  4-ply  Greater number of plies usually indicates a greater load-carrying capacity

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only DOT Serial Number  Identifies the manufacturer, plant location, construction, and date of manufacture  Stamped into the sidewall  Department of Transportation rating means the tire has passed prescribed safety tests

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Tire Grades  Tread wear  given as a number, 100 to 500  higher number is more resistant to wear  Tire traction  given as an A, a B, or a C  an A rating has the most traction  Tire temperature resistance  given as an A, a B, or a C  an A rating resists temperature buildup best

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Speed Rating  Maximum allowable sustained road speed a tire can safely withstand without failure  Ratings range from B to Z  B rating – 31 mph or 50 km/h  Z rating – 149 mph or 238 km/h

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Asymmetric Tires  Have different tread patterns on inner and outer edges  inner – improves traction on wet surfaces  outer – improves cornering on dry surfaces  Must be mounted so proper edge faces outside of wheel

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Directional Tires  High-performance tires  Rotate in a specific direction to minimize hydroplaning  Must be mounted in the proper location so they rotate in the desired direction

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Compact Spare Tire This is a high-pressure spare, requiring 60 psi (415 kPa)

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Self-Sealing Tires  A coating of sealing compound is applied to the liner  If a nail punctures the tire, air pressure will push the soft compound into the hole to stop air leakage

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Self-Sealing Tire Action A. Nail punctures the tire B. The nail is pulled out C. Sealing compound flows into the hole

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Retreads  Used tires that have had a new tread vulcanized to the old carcass, or body  Large truck tires are often recapped because of the high cost of new truck tires

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Run-Flat Tires  Have an extremely stiff sidewall construction  Still usable with a loss of air pressure  Tire will retain most of its shape because the sidewall is strong enough to support the vehicle weight

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Run-Flat Tires

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Wear Bars When too much tread has worn away, solid rubber bars will show up across the tread

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Tire Pressure Monitoring System  Pressure sensors are mounted on each wheel  If tire pressure is not correct, the sensor produces a radio signal  The signal is received by a module that turns on a dash warning light

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Pressure Sensor

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only System Operation

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only  Designed to support the tire while withstanding loads from acceleration, braking, and cornering  Made of steel, aluminum, or magnesium

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Wheel Components

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Mag Wheels Aluminum or magnesium wheels are often called mags

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Drop-Center Wheel  Allows for easier installation and removal of the tire  The center of the wheel is smaller in diameter than the rim  When installing a tire, the tire bead can fall into the recess, and then, the other side of the tire bead can be forced over the rim

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Drop-Center Wheel Note the smaller diameter in the center than in the rim

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Dimensions of a Wheel

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Safety Rims Small ridges on the rim hold the tire on the wheel during a tire blowout or flat

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only  Valve stem  pressed into a hole in the wheel of a tubeless tire to allow inflation and deflation  Valve core  spring-loaded air valve threaded into the valve stem  Valve stem cap  protects the air valve and stem threads from dirt, moisture, and damage

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Valve Stem Assembly A valve stem snaps into the hole in the wheel The press fit forms an airtight seal The valve core screws into the valve stem body

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only  Lug nuts  hold the wheel and tire assembly on the vehicle  Lug studs  special studs that accept the lug nuts  Lug bolts  used instead of nuts  screw into threaded holes in the hub or axle flange

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Lug Nut and Stud A stud is pressed into the hub or axle flange If metric or left-hand threads are used, markings will normally be present

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only  Small lead weights  Attached to the wheel rim to balance the wheel-and-tire assembly  Used to offset a heavy area of the wheel and tire

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only  Allow the wheel or hub to turn freely  Most wheel bearings are tapered roller bearings or ball bearings

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Tapered Roller Bearing Lubricated with high-temperature grease

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Ball Bearing Balls allow parts to rotate with a minimum amount of friction and wear

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Hub and Wheel Bearing (Tapered Roller Bearings)  The spindle is stationary, providing a mounting place for the wheel bearings, hub, and wheel  The hub is partially filled with grease to lubricate the bearings  The nut on the end of the spindle allows adjustment of the bearing preload

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Hub and Wheel Bearing (Tapered Roller Bearings)

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Used on the front of rear-wheel-drive cars or the rear of front-wheel-drive cars Hub and Wheel Bearing (Tapered Roller Bearings)

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only  The front drive axle extends through a stationary spindle  A special free-wheel, or locking, hub transfers power from the axle to the hub-disc assembly when in four-wheel drive Hub and Wheel Bearing (Four-Wheel Drive)

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Hub and Wheel Bearing (Four-Wheel Drive) Front axle, brakes, hub, and wheel bearing assembly

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Hub and Wheel Bearing (Ball Bearings)  The drive shaft fits through the center of the bearings  The hub is splined to the axle shaft  The ball bearings are lubricated by thick, high-temperature grease

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Hub and Wheel Bearing (Ball Bearings)

© Goodheart-Willcox Co., Inc. Permission granted to reproduce for educational use only Commonly used on the front of front-wheel-drive vehicles Hub and Wheel Bearing (Ball Bearings)