Modern Auto Tech Study Guide Chapter 65 & 66 Pages 1241 1278 Tires, Wheels, Bearings 51 Points Automotive Service Danger of Old Tires!!
Tires Manufactured Since 2000 Since 2000, the week and year the tire was produced has been provided by the last four digits of the Tire Identification Number with the 2 digits being used to identify the week immediately preceding the 2 digits used to identify the year.
Tires Manufactured Before 2000 The Tire Identification Number for tires produced prior to 2000 was based on the assumption that tires would not be in service for ten years. While they were required to provided the same information as today s tires, the week and year the tire was produced was contained in the last three digits. The 2 digits used to identify the week a tire was manufactured immediately preceded a single digit used to identify the year.
1. Tires act as a between the road & the vehicle as well as providing with the road surface. Tires transmit driving torque, as well as braking, and cornering forces to the road. Cushion, Traction
2. tires are the most common of the (air filled) type. Tubeless, Pneumatic
3. The of the tire holds its sidewalls snugly against the wheel flanges.
4. A tire s resistance is the amount of friction produced as it operates on the road surface. The less rolling resistance a tire has, the better the mileage of the vehicle will be. Rolling Static Potential
5. plies run at a slant & plies run at right angles from bead to bead. Bias, Radial
6. Radial tires have very stable footprints which improve, cornering, & wear. Traction, Handling, Braking, Mileage you name it!
7. Tire sizes that start with a P indicate a car tire, T indicates a spare, C indicates a tire and indicates a Light Truck tire. P = Passenger T = Temporary C = Commercial LT = Light Truck
8. The number following the 1st letter designation indicates the tire section in millimeters. Height Width Length
9. is the height to width ratio (often called tire profile) and is expressed as a % of height to width. Aspect Ratio Gear Ratio Braking Ratio
10. Rim or wheel, expressed in inches from flange to flange is the last # in the tire size. Height Width Diameter
11. The maximum pressure (printed on the sidewall) is not the recommended inflation pressure.
12. Uniform Tire Quality Grading System rates (100 500), (ABC), and resistance (ABC). The 3 T s of the UTQGS Tread Wear, Traction, Temperature Resistance
13. Tires also have an alphabetic rating that ranges from B to Z (31 mph to 149 mph). Speed Load Mileage
14. tires get mounted with a certain side outward & tires are rotation specific. Directional
15. High pressure, temporary, compact spare tires (doughnuts) typically get inflated to psi. 35 PSI 150 PSI 60 PSI
16. Variation in tires include self, retreads, rain tires, and run tires. Self Inflating & Run Flat Self Sealing & Run Flat Self Service & Run Full
17. If too much tread has worn off of the tires, solid rubber will show up across the tread. Wear Bars Rub Strips Median Strips
18. Vehicles are equipped with radio signal, direct or indirect, tire monitoring systems. TPMS = Tire Pressure Monitoring System
TPMS
19. Wheels are commonly made of,, magnesium & even composite plastic. Steel, Aluminum Iron, Chromium Brass, Titanium
20. The area of a wheel allows for easy removal of the tire but they must be fit with small, raised lips around the rim to keep the tire beads from sliding into that dropped area if they go flat. Drop Center Wheel Rim Drip Cap
21. Air is added to the tire through a valve which is fit with a spring loaded, one way, valve core. Valve Core Valve Stem Valve Guide
22. Lug thread on to lug studs to anchor the wheel to the hub. Some vehicles use lug bolts instead VW, Mercedes, etc. Lug Nuts vs. Lug Bolts
23. For balancing, lead wheel are added to the rim to prevent tramp & shimmy vibration. Weights
24. Ball or roller wheel mounted in a allow the tire & wheel assemblies to turn smoothly on the. Castle nuts w/ cotter pins secure the hub on to the spindle. Bearings, Hub, Spindle Spindles, Hub, Bearing Knuckles, Fist, Finger
~~~ Automotive Service 25. Tire problems can show up as, abnormal wear, steering wheel pull, and other symptoms that are similar to those caused by suspension and brake systems. Vibrations, Patterns
26. is a common destructive problem that wears both outer edges of the tread area. It can heat up the tire during operation causing ply separation while lowering mpg. Under Inflation
27. causes wear in only the center of the tread and produces a hard ride. Over Inflation
28. Proper tire inflation specifications are not found on the tire sidewall! Either the manual or the tire placard mounted inside the driver or passenger door jamb have the correct psi specs Owner s Manual General Repair Manual Tire Manual
29. Tire is the action of moving the tires at manufacturer specified mileage intervals to different locations on the vehicle to increase tire life. This is done in a specified pattern too. Relation Rotation Revitalization http://www.tirerack.com
30. Tires & wheels should always be tightened on to the hub using a wrench to prevent distortion of the wheel, hub, brake rotors, or brake drums. Use an X or star tightening pattern. Torque Impact Cross
31. Both radial (right angle) and lateral (axial) tire & wheel (wobble) should be well under.100 Preload Runout Backlash
32. imbalance of the tire & wheel causes tramp or hop (up & down vibration). Static Attic Automatic
33. imbalance of the tire & wheel causes both tramp and shimmy (side to side vibration). Dynamic Ceramic Systematic
34. When servicing (repacking) non drive wheel bearings, special wheel bearing grease is recommended instead of regular all purpose, chassis grease. High Temperature Low Viscosity High Intensity
35. When repacking wheel bearings, partially fill the hub with. Grease Oil SAE #80w90 Gear Lube
36. Always be sure to install new grease on the hub and new pins on the castle nut when repacking wheel bearings! Seals & Wrist Pins Seals & Cotter Pins Boots & Cotter Pins
37. After repacking wheel bearings, it is critical to the spindle nut to manufacturer specs following mfgr. procedures! Tighten or Torque
Know this picture of tire inflation problems for the test
Know this system of tire sizing for the test