The document discusses various aspects of tires and wheels, including their design and components, types of tires, defects to look for, how to read sidewall information, proper inflation and maintenance. It also covers topics like how ABS, stability control, and suspension work with tires to maximize traction. Tire pressure monitoring systems, wheel specifications, and the proper procedure for changing a tire are additionally explained.

1. Tires and Wheels

2. General Tire Function
• Support vehicle weight
• Provide ride comfort
• Develop traction on the road surface
• Contribute to directional stability

3. So How does it apply?
• ABS
• Stability Control
• Suspension Set up
• Shock dampening
– All these try to maximize the tires available
traction

4. Typical Tire Design
• Bead wire and bead filler
• Liner
• Steel reinforcement
in the sidewall
• Sidewall with hard
side compound
• Rayon carcass plies
• Steel belts and
jointless belt cover
• Undertread compound
and high-grip tread
compound

5. Tire-Related Components
• Valve stems
and
valves
– Replace with
new tires
• Compact spare
• Tire placard and
inflation
pressure

6. Tire Ply and Belt Design
• Bias-ply
– 25°-45° to Center
• Belted bias-ply
• Belted radial-ply
– 10°-30°

7. Advantage of Radial Tires

8. Tire Defects
• Separations and bulges
• Tread chunking, tearing, or cracking
• Sidewall fatigue or cracking from Ozone
• Bead chafing or broken wires
• Breaks in sidewall or tread area
• Excessive radial or lateral runout
• Conicity

9. Tread Separation
Not a retread!

10. Ford and The Firestone Tire
• Side Wall Fatigue/Cracking

11. Sidewall Defects
Indentation that is at 90° = Okay Bulge in sidewall = Bad

12. Other tire wear

13. Tread Measurement

14. Tire Ratings and Sidewall
Information
• Tubeless or
tube-type
construction
• Type of carcass
construction
• Aspect ratio
• Ply design
• Rim diameter
• Load rating

15. Tire Ratings and Sidewall
Information

16. Passenger Tire Load Ratings

17. Light Truck Tire Load Ratings
• The tire will specify
max load @ max
inflation

18. Speed Ratings
• Most passenger tires
are rated at “R”, “S”
and “T”
• High performance
cars are rated “V”, “Z”
and “$$$” above!

19. DOT #
• Mfg.’s Plant ID#
• Tire Size Code
• Tire Type
(optional)
• Date of Mfg.
– Week
– Year

20. Uniform Tire Quality Grading
• Tread wear
– 100, 200, 300, 400
• Traction
– 40 mph wet straight
line stopping
• AA, A, B, C
• Temperature
– A over 115mph
– B 100-115mph
– C 85-100mph

21. Specialty Tires
• Puncture sealing tires
– Gooey Stuff in Tires
• Mud and snow tires
– More aggressive tread
• All-season tires
– Can have silica mixed
in rubber compound for
ice traction
• Run-flat tires
– Michelin PAX system

22. Michelin PAX Tire

23. Other “Run Flat” Tires

24. The future way to fix flat tires

25. Directional Tires
• Run in proper direction to help channel water
• Pay attention to marking on sidewall

26. What is the correct pressure for
this tweel?
• This is an idea
Michelin has. An
airless tire and is
currently working with
Audi on a prototype
for the street.

27. Replacement Tires
• Mud and snow tires must be the same size as the other
tires on the vehicle
• Why?
• ABS and TPMS codes will set
• A four-wheel-drive vehicle should have the same size
tires on all four wheels within 3/32”
• Automatic 4x4 problems will occur
• Standard 4x4 Binding will occur
• All ratings must equal original tire ratings

28. How do we know what tire to
put on a car?
• Look at the sticker
on the door jam!
• It will tell you what is
the proper size, and
inflation.
• $10,000 Question…
Why is the correct
size important?
The PCM is calibrated with the
factory size tires. The wrong size
could cause a Smog Failure, fuel
economy issues, early warranty
expiration and
speedometer/odometer inaccuracies.

29. Summer Air & Winter Air
• Nitrogen vs. Shop air
– Nitrogen molecules are fatter than air
– No moisture in compressed nitrogen
– Usually identified by Green Valve Stem Caps
– Snake oil marketing

30. Tire Pressure Monitor

31. Tire Pressure Monitor
• By 2008, all cars and trucks under 10,000
GVW must be equipped with a tire
pressure monitor capable of sensing a
25% loss of air pressure. That’s just an 8
psi drop in a tire inflated to 32 psi!
• How will hot/cold will affect tire pressure?

32. Tire Pressure Monitoring
Systems
• Two Types
– Direct
• Sensor in tire
– Indirect
• Uses ABS Wheel Speed sensors to verify rolling
diameter

33. Tire Pressure Monitoring
Systems
• Tire pressure monitoring
system with valve stem
sensors

34. Tire Pressure Monitoring
Systems
• Messages related to the TPMS are:
– Running tire pressures in instrument cluster
– Warning tire very low
– Check tire pressure
– Tire pressure sensor fault
– Tire pressure monitor fault
• Resetting light
– Use of special tools
– Reset switch on dash and drive
• Caution!
– Don’t use liquid tire sealers or balancing fluids!

35. Wheel Rims
• Stamped steel
• Cast aluminum
• Forged aluminum
• Pressure cast aluminum,
chrome-plated
• Magnesium
• Lug nut design

36. Parts of a Rim

37. Wheel Offset
Excessive offset can damage wheel bearings

38. Wheel and Tire Service
• Tire rotation
• Wheel and tire removal and replacement
• Tire demounting and remounting
• Tire inspection and repair
– Plug
– Cold patch
– Hot patch

39. What’s wrong with this picture?

40. How to Change A Tire
• Pull over in safe place, argue with spouse
• Turn on Emergency Flashers
• Chock Wheels with rock etc.
• Place jack under vehicle on solid ground
• Place jack on suggested lift points
– Probably first chance to REALLY read
Owners Manual…if you can find it!
• Loosen lug nuts
• Raise vehicle so tire is just off ground

41. How to Change A Tire
• Remove lug nuts and place in hubcap
• Remove flat tire
• Find lug nuts in dirt after kicking hubcap
• Install flat spare and tighten lug nuts finger tight
• Lower vehicle to ground
• Tighten lug nuts in “Star” pattern
• Remove wheel chocks
• Drive to slowly to nearest shop with flat spare
tire and have lug nut torque checked!
• Fill spare tire, take clothes to dry cleaners

42. How to Change A Tire
• Pull over to safe place
• Turn on emergency flashers
• Pick up Cell Phone
• Call AAA!