1. Modern Automotive Technology PowerPoint for by Russell Krick
Publisher The Goodheart-Willcox Co., Inc. Tinley Park, Illinois

2. Chapter 66
Tire, Wheel, and
Wheel Bearing
Service

3. Contents Tire, wheel, and wheel bearing diagnosis
(8 Topics)
Tire, wheel, and wheel bearing diagnosis
Wheel cover removal and installation
Tire maintenance
Measuring tire and wheel runout

4. Contents Wheel balance Mounting and dismounting tires
Tire puncture repair
Wheel bearing service

5. Tire, Wheel, and Wheel Bearing Diagnosis
Problems usually show up as vibrations, abnormal tread wear patterns, steering wheel pull, abnormal noises, and other symptoms

6. Diagnosing Tire Problems
Inspect the tires for problems
Check both sidewalls and the tread area
If necessary, road test the vehicle to verify the customer complaint
Make sure the symptoms are not being caused by steering, suspension, or front wheel alignment problems

7. Wiggle the tire to check for dry, rough, or loose wheel bearings
Inspecting the Tires
Wiggle the tire to check for dry, rough, or loose wheel bearings

8. Typical damage found on used tires
Tire Impact Damage
Typical damage found on used tires

9. Tire Wear Patterns

10. Tire Inflation Problems
Correct tire inflation is important to the service life of a tire
assures the full tire tread contacts the road
Underinflation
wears the outer edges of the tread
sidewalls flex, building up heat
Overinflation
wears the center of the tread
produces a rough ride

11. Tire Inflation Pressure

12. Tire Vibration Problems
When one of the front tires is vibrating, it may be felt in the steering wheel
When one of the rear tires is vibrating, it will be felt in the center and rear of the car

13. Causes of Tire Vibration

14. Tire Noise “Thumping” sound caused by ply separation
“Whine” due to abnormal tread wear
When these noises occur, inspect the tire for an out-of-round condition or tread cupping
these conditions require replacement

15. Wheel Bearing Noise Produced by a dry, worn wheel bearing
When balls or rollers are damaged from lack of lubrication, they may emit a humming or growling sound
Checking the bearings:
raise the vehicle on a lift
rotate the tire by hand
feel and listen for bearing roughness
wiggle the tire to check for looseness

16. Removal and Installation
Wheel Cover
Removal and Installation

17. Pry between the wheel and cover at four alternating points
Wheel Cover Removal
Pry between the wheel and cover at four alternating points

18. Wheel Cover Installation
Hold the wheel cover in place with the valve stem sticking through the cover

19. Tire Maintenance
Maintenance procedures include periodic inspection, inflation pressure checks, and tire rotation
These maintenance steps help ensure safety and longer tire life

20. Checking Tire Inflation Pressure
Remove the valve stem cap
Press the tire gauge squarely over the stem
Compare the reading to the maximum pressure printed on the tire sidewall or in the operator’s manual
Adjust the pressure as necessary
Reinstall the cap

21. Tire Service Tools

22. Rotating Tires Ensures maximum tire life
The front and rear tires wear differently
Rotation helps even out tire wear
Tires are rotated at specific intervals, such as every 3000 miles (5000 km)

23. Tire Rotation Patterns

24. Torquing Lug Nuts
Torque is very important, especially on vehicles with mag wheels and lightweight hubs
Overtorquing can cause wheel and hub distortion, or brake pulsation
Undertorquing might allow the lug nuts to loosen and the wheel to fall off

25. Torque the nuts to specifications in a crisscross pattern
Torquing Lug Nuts
Torque the nuts to specifications in a crisscross pattern

26. Replacing Lug Studs Lug studs can become stripped or worn
Force out the old stud with a pressing tool
To install new studs, use flat washers and a lug nut
Draw the new stud into place by tightening the nut on the washers
If the hub is removed from the vehicle, a hydraulic press can be used

27. Measuring Tire and Wheel Runout Tire runout Wheel runout
caused by ply separation or manufacturing defect
Wheel runout
caused by impact damage or incorrect welding of the spider and rim

28. Lateral Runout Side-to-side movement of a wheel or tire
Maximum for a tire
0.090" (2.0 mm)
Maximum for a wheel
0.045" (1.0 mm)

29. Measuring Lateral Runout
Mount a dial indicator with the stem against the sidewall and side of the rim. Check the reading at several points.

30. Radial Runout
Difference in radius from the center axis of rotation (out or round)
Maximum for a tire
0.060" (1.5 mm)
Maximum for a wheel
0.035" (0.9 mm)

31. Measuring Radial Runout
Mount a dial indicator with the stem against the tread and the lip of the rim. Check the reading at several points.

32. Wheel Balance
Improper wheel balance is a common cause of tire and steering wheel vibration
When one side of a tire is heavier than the other, centrifugal force tries to throw the heavy side outward when the tire is rotating

33. Caused by a heavy spot located in the center of the tire tread
Static Imbalance
Caused by a heavy spot located in the center of the tire tread

34. The heavy spot is to one side of the tread or on the sidewall
Dynamic Imbalance
The heavy spot is to one side of the tread or on the sidewall

35. Wheel Balancing Wheels are balanced by adding wheel weights
Most weights are press-fit onto the wheel
Weights for some mag wheels stick onto the wheel with an adhesive backing

36. Weights are often kept on the balancing machine
Wheel Balancing
Weights are often kept on the balancing machine

37. Wheel Balancing Static balancing Dynamic balancing
add weights opposite the heavy area of the wheel
if a large amount is needed, add half to the inside and half to the outside of the wheel
Dynamic balancing
add weights exactly where needed
the dynamic balancing machine will indicate where weight must be added

38. Wheel Balancing

39. On-Car Balancing Follow the equipment operating instructions
Wear eye protection
Remove rocks and debris from the tread
Place the vehicle on a jack stand
When using the engine to spin the drive wheels, do not exceed 35 mph (40 to 56 km/h)
when one wheel is on the floor, the free wheel will turn at twice the indicated speed

40. With a limited-slip differential, raise both rear wheels off the floor
On-Car Balancing
With a limited-slip differential, raise both rear wheels off the floor

41. Wheel Balancers
A wheel balancing machine is used to determine which part of a wheel assembly is heavy
Bubble balancer
static balance
Off-car balancer
static or dynamic balance
On-car balancer

42. The wheel and tire assembly is mounted
Bubble Balancer
The wheel and tire assembly is mounted
on the machine

43. Add weights until the bubble is centered
Bubble Balancer
Add weights until the bubble is centered

44. Off-Car Balancer
The wheel and tire assembly is mounted on the machine and rotated
The machine will indicate where weights should be added
After adding weights, spin the tire again to check for vibration

45. Off-Car Balancer

46. On-Car Balancer
Provides an electric motor to spin the wheel and tire assembly
An electronic pickup or hand-operated device is used to determine where weights are needed
Balances the wheel cover, brake disc, and lug nuts along with the tire and wheel

47. Mounting and Dismounting Tires
A tire changing machine is used to force the tire on and off the wheel
prevents tire or rim damage
reduces the labor required

48. Power head turns the bar to force the beads over the rim
Tire Changing Machine
Power head turns the bar to force the beads over the rim

49. Applies tremendous force to stretch the tire bead on and off the wheel
Tire Changing Machine
Applies tremendous force to stretch the tire bead on and off the wheel

50. Safe Work Practices Wear eye protection
Keep your fingers out of the way
Never mount a tire on a rim that is not smooth and clean
Always lubricate the bead and wheel flange with the proper lubricant
Only inflate a tire on the machine, or in a safety cage as recommended

51. Safe Work Practices
Stand away from the tire when adding air; a loud “pop” sound will indicate when the beads seat
Do not exceed 40–50 psi (276–345 kPa) when initially inflating a tire
After inflation, install the core and reduce the tire pressure to the recommended limits

52. Automated Tire Changer
Uses a rubber wheel to force the bead back over the wheel

53. Tire Puncture Repair Repairs must be made carefully
Improper repair could result in a tire failure and an accident

54. Finding a Leak Inflate the tire with air
Place the tire in a drum of water, or wet the tire with a water hose
Look for air bubbles forming on the tire or around the bead at the rim
Bubbles indicate leakage
Mark the leak with a crayon or chalk

55. Repairing a Leak Remove the tire from the rim
Inspect the inside of the tire carefully
Fill the injury using a recommended plug or liquid sealant
Select a patch that extends well beyond the damaged area

56. Repairing a Leak Scuff the area that the patch will cover
Apply the proper cement to the inner liner
Remove the covering from the adhesive side of the patch and carefully place it on the inner liner

57. Use a stitcher tool to bond the patch to the inner liner
Repairing a Leak
Use a stitcher tool to bond the patch to the inner liner

58. Tire Repair Practices
Always dismount the tire and patch the inner liner
Never repair sidewalls or tires with punctures larger than 1/2" (13 mm)
When removing an object from the tire, reduce the air pressure to 15 psi (103 kPa) or lower
Broken strands in steel belts indicate serious damage and could puncture the patch

59. Wheel Bearing Service Wheel bearings are normally filled with grease
If the grease dries out, the bearing will fail
Some bearings are serviceable
Some bearings are sealed units

60. Nondriving Wheel Bearing Assembly

61. Wheel Bearing Removal (Nondriving Wheels)
Raise the vehicle on a lift
Remove the wheel, grease cap, cotter pin, adjusting nut, and safety washer
Pull out the outer wheel bearing

62. Wheel Bearing Removal Screw the nut back on the spindle
Slide the hub outward
when the inner bearing catches on the adjusting nut, the grease seal and inner wheel bearing will pop out
Wipe the bearings and races clean

63. Wash and dry the bearings
Bearing Inspection
Wash and dry the bearings

64. Bearing and race problems
Bearing Inspection
Bearing and race problems

65. The bearing and race are replaced as a set
Bearing Replacement
The bearing and race are replaced as a set
Drive out the old race

66. To install a new race, use a driving tool
Bearing Replacement
To install a new race, use a driving tool

67. Greasing the Bearings
Pack the bearing with high-temperature wheel bearing grease
Use a packer or grease it by hand
Make sure the grease is worked completely through each bearing cage and around every ball or roller

68. Greasing the Bearings

69. Bearing Installation Place the inner bearing in its race
Install the new grease seal in the hub
Wipe the spindle clean
Slide the hub into position
Install the outer bearing
Install the safety washer and adjusting nut
adjust the nut as described in the manual

70. Typical Bearing Adjustment

71. Driving Hub and Wheel Bearing Assembly

72. Wheel Bearing Removal (Driving Wheels)
Loosen the wheel lug nuts and spindle nut
Raise the vehicle on a lift
Remove the lug nut or bolts, the wheel, and the axle nut

73. Wheel Bearing Removal Remove the caliper and hang it to one side
Unbolt the brake disc from the hub
Remove the steering knuckle and hub assembly

74. Use a puller to remove the hub from a steering knuckle
Wheel Bearing Removal
Use a puller to remove the hub from a steering knuckle

75. Remove the old bearing using a driver or hydraulic press
Wheel Bearing Removal
Remove the old bearing using a driver or hydraulic press

76. Wheel Bearing Installation
Install the new bearings and a grease seal

77. Wheel Bearing Installation
Press the hub into the steering knuckle

78. Wheel Bearing Installation

79. Wheel Bearing Installation
Install the steering knuckle assembly
Install the brake disc, caliper, and other components
Tighten the spindle nut and lug nuts to specifications
Stake the spindle nut or install a cotter pin as required
Lower the vehicle

80. Spindle Nut Retainers

81. Servicing Rear Wheel Bearings (Front-Wheel-Drive)
Two types of rear wheel bearings are used:
serviceable
nonserviceable (sealed units)

82. Rear Hub Assembly (Front-Wheel-Drive)
This unit is not serviceable

83. Bearing and Hub Replacement
When a nonserviceable unit fails, the bolts holding the bearing and hub to the axle or control arm must be removed
When installing the new assembly, torque the bolts to specifications
New fasteners may be specified

84. Wheel Bearing Service
When a serviceable wheel bearing is used, it can be disassembled and packed with grease
Follow the service manual procedures