Tire Fundamentals 1 Tire Function Tires serve two

Tire Fundamentals 1

Tire Function ØTires serve two basic functions. ØProvide cushion between and the road and the metal wheel. ØProvide adequate traction (friction) with the road surface 2

Tires Manufacturers Ø There are many different tire manufacturers. Ø How many do you recognize? 3

The Parts of a Tire ØTread ØSidewall ØBody Plies ØSteel Belts ØLiner ØBeads 4

Reading the Sidewall 5

Tire Manufacturers & Models Ø Tire manufacturers are the companies that make the tires Ø Tire models are the different types of tires that company produces E. g. Tire manufacturer = TOYO Tire Model = PROXES T 1 -S 6

Tire ‘Codes’ or ‘Sizes’ 7

Tire Type ØP-Metric System ØLetter designates tire type: ü “P” Passenger tire ü “LT” Light truck tire ü “C” Commercial tire ü “T” Temporary/spare tire 8

Tire Width Ø Tread width in millimetres Ø This tire’s width would be 235 mm 9

Aspect Ratio Ø Ø Tire height-to-width ratio Aspect ratio = 75 Sidewall height is 75% of the tire width Aspect ratio of this tire is 235 mm X 75% = 176 mm tall sidewall 10

Construction Ø“R” designates the tire is a radial tire Ø Radial tires have plies that go from bead to bead 11

Rim Diameter Ø Rim diameter is given in inches § 13 = 13” § 14 = 14” § 15 = 15” etc. 12

Load Index Ø 2 -digit # that determines the tire’s maximum load carrying capacity Ø 82 Load Index = 1047 lbs 13

Speed Rating Ø Maximum allowable road speed a tire can safely withstand without failure Ø Letter system Ø For Example “H” Speed Symbol = 130 mph 14

Lamborghini Gallardo 15

Mud and Snow Rating Ø M+S indicates the tire can be used in mud and snow applications Ø All season tires should not be used in snowy conditions unless they have the mountain snowflake symbol 16

Treadwear Rating Ø Treadwear is given as a number Ø The higher the number, the longer the tire will last Ø 100 = Baseline Ø More than 100 = Better Ø Less than 100 = Poorer ØIf it does not say, it is under 100 17

Traction Rating Ø Traction is given as an A, B, or C rating A = best traction B = intermediate traction C = acceptable traction 18

Temperature Rating Ø Temperature is also given as an A, B, or C rating A = best B = intermediate C = acceptable Ø The higher the rating the more resistant to temperature build-up Ø The more a tire heats up, the quicker it wears 19

Department of Transportation # Ø Also known as the DOT # Ø The DOT # identifies: Ø Manufacturer of tire Ø Plant location Ø Construction Ø Date of manufacturer Ø Used for warranties, recalls, etc. 20

Maximum Load Rating Ø The amount of weight a tire can carry at the recommended air pressure Ø E. g. 1300 lbs Ø Are the tires needed for a minivan or delivery van? Ø Don’t do what this person did! 21

Air Pressure (Lab) Ø Checking air pressure is important ØPressure ØPounds Per Square inch (PSI) Ø Benefits of correct air pressure are: Ø tires last longer Ø save fuel Ø better handling 22

Inflation Problems Excessive wear on outer tread ü Tread wears evenly Excessive wear in middle of tread 23

The tire information sticker is called a placard , it is located on the door post, in the glove box or on the gas tank door. The placard indicates the correct tire size & cold tire pressure. 24

When do tires need replacing? 2/32” Ø A tire is completely worn out when the tread-depth is 2/32” or less Ø An American penny will work as an accurate gauge Ø The distance between the side of the penny and Lincoln’s hair is exactly 2/32” ØWear Bars (Built in gauges) 25

Tire Worksheet (Lab) Ø Pair up with a partner Ø Fill out Tire Worksheet Ø It is one of your mandatory labs! Ø You can inspect your own car or shop car 26

Tire Wear: Things to think about… Weight Braking Steering Tires with ‘drive’ 27

When tires need replacing We remove the tire Replace it Balance the new tire DEMO TIME!! 28

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Camber Can improve handling Negative: the top leans in Positive: The top leans out 30

Caster Positive: Stability Straight travel 31

Tire Rotation and Flat Tire Lab Ø Pair up with partner Ø Fill out the Lab Ø You may work on your own car or a shop car Ø Get permission before using the hoist or Jack! 32

Movie! 33

Roadside Repair VS Full Shop Watch for differences between a ‘side of the highway’ job and a proper job Ø Get home and properly fix things 34

Roadside Tire Changing – Step 1 Ø Park away from traffic. ØPut the parking brake on and chock the wheels Ø If the wheel has a wheel cover, pry it with the flat end of the tire iron. ØNOTE: not all need prying 35

Roadside Tire Changing – Step 2 Ø Break the lug nuts loose by turning them counter-clockwise. Ø If the nuts won’t loosen, carefully use extra force by standing on the lug wrench. 36

Roadside Tire Changing – Step 3 Ø Refer to the car’s owner manual for jack position. Ø Newer cars have indentations in the rocker panel for where the jack goes. 37

Roadside Tire Changing – Step 4 Jack up the car. 38

Roadside Tire Changing – Step 5 Ø Once the tire is up off the ground, remove the lug nuts. Ø Put the loose nuts in a safe place such as inside the wheel cover. 39

Roadside Tire Changing – Step 6 Ø Remove the flat tire. 40

Roadside Tire Changing – Step 7 Ø Lift the spare onto the wheel studs. Ø Next, thread on the lug nuts by hand. q Remember: Pointed end in first. 41

Roadside Tire Changing – Step 8 Ø Using the tire iron, tighten the lug nuts in an "X" pattern. Ø This secures the wheel to the hub evenly. 42

Roadside Tire Changing – Step 9 ØLower the vehicle, remove the jack and tighten the nuts. Ø Remember most spares are only temporary. Ø Do not exceed speeds of 50 km per hour on spare. 43

Differences? Torque wrench Wheel chock Solid ground Concrete vs Ashfault Safety Glasses! PPE! ex. Cover-alls 44

Flat Tire Lab Ø Use your own vehicle. Ø By yourself or only one partner. Ø No tools from the shop allowed. Ø Use only what is in your trunk. 45

Tire Rotation (Lab) RWD Ø Ensures maximum tire life FWD Ø Evens out tire wear Ø Tires should be rotated every 5, 000 kms 4 x 4 46

Ideas For Labs Flat Tire Lab Tire Change Tire Rotation Using the Hoist Tire Data Lab Tire pressure Lab (1 p) 47