D - Wheels, Tires and Hubs

Question 1

Name the two basic styles of wheels used on heavy equipment.

Answer 1

Spoke wheels and disc wheels.

Question 2

Explain the main difference between spoke wheels and disc wheels.

Answer 2

Spoke wheels are supported by bearings and can be considered as a type of hub. Disc wheels are fastened to a hub.

Question 3

Identify the two types of disc wheels in terms of how they are piloted.

Answer 3

Stud pilot - centred by the studs and nuts

Hub piloted - centred by the

Question 4

When dual tires and wheels or rims are used, a spacer must also be used. Explain the purpose of that spacer.

Answer 4

The spacer ensures that the two tires are separated sufficiently to prevent contact during normal operation.

Question 5

True or False: It is permissible to use any style of wheel nut when mounting stud piloted wheels.

Answer 5

False; Only use cone/ball type tapered wheel nuts.

Question 6

True or False: It is permissible to use one stud piloted wheel and one hub piloted wheel as a dual wheel set.

Answer 6

False; Only use a set of stud piloted OR a set of hub pivoted wheels as a dual wheel set.

Question 7

Identify two main types of the air retention methods.

Answer 7

Tube type.

Tubeless type.

Question 8

Tire tread designs can be two general styles. Name and explain when those styles are typically used.

Answer 8

Rib - non-traction, steering on-highway use, trailer

Lug or block - traction applications

Question 9

Explain two major types of tire construction in common use.

Answer 9

Bias Ply - angled cords (plies) built up into layers

Radial ply - steel plies at 90 degrees to the need, with steel reinforcing belts on the tread circumference

Question 10

True or False: Tires are matched by checking the size on the size on the side wall of the tires.

Answer 10

False; Tires must be measured for circumference and diameter and be matched within allowable limits.

Question 11

Identify the equipment that could be used to measure tires in the process of matching them together.

Answer 11

A tape measure, a large square or a matching stick (large calliper), or a tire straight edge or a a length of string held tightly across all tires.

Question 12

True or False: When matching tires on a tandem axle assembly, the front axle tire set can be matched, but slightly different from a matched rear axle tire set.

Answer 12

False; Ideally both axle sets are identically matched.

Question 13

Identify the two main tire inflation problem. Of these two explain which is worse and why.

Answer 13

Under-inflated - worse - heat can destroy tire.

over-inflated - faster tire wear

Question 14

As an apprentice, explain what you could do to prevent personal injury when working around tires/wheels and rims.

Answer 14

Get training in safe tire/wheel/rim handling. Follow all instructions. Ask for help when uncertain. Know the most likely explosive force trajectories and stay clear.

Question 15

Explain what visual checks you should do before moving any tire assembly.

Answer 15

Visually inspect the tire/wheel/rim for signs of overheating, damage, cracks, and mismatched parts.

Question 16

Describe the first thing you would do prior to removing a tire assembly from a vehicle for repair or before working on a loose tire assembly.

Answer 16

Remove all air from the tire by removing the valve core. Push a wire into the valve stem to ensure no blockage exists and all air is out.

Question 17

True or False: It is permissible to weld or braze on a steel wheel.

Answer 17

False; Do not weld, braze, rework or heat a wheel or wheel components.

Question 18

Describe the equipment you would use to safely inflate a tire and wheel or rim assembly

Answer 18

Place the tire assembly in a safety cage. Use a length of air hose with a pressure gauge and an inflating/deflating mechanism attached. Stand clear and seat the beads with no more then 276 kPa (40 psi) pressure.

Question 19

True or False: It is permissible to mix wheel and rim side rings and lock rings.

Answer 19

False; Never mix wheel/rim components. Always match the parts together.

Question 20

True or False: Axle wheel hubs generally use a set of two tapered bearings. These bearings do not require adjustment.

Answer 20

False; Bearings operating as sets must be adjusted.

Question 21

True or False: Wheel bearings are only lubricated by grease.

Answer 21

False; Oil is often used.

Question 22

True or False: All wheel studs have right-handed threads.

Answer 22

False; Some have left-handed threads.

Question 23

Identify the two general types of wheel balance problems.

Answer 23

Static - centralized heavy spot across a tread or rim

Dynamic - heavy spot on a side of a tire tread or wheel rim

Question 24

Which tire imbalance is identified by the word Bounce?

Answer 24

Static imbalance

Question 25

Which tire imbalance is identified by the word Shimmy?

Answer 25

Dynamic imbalance

Question 26

True or False: Wheel weights used for balancing tire assemblies must be a specific shape and contour.

Answer 26

True

Question 27

True or False: Cracks in steel wheels can be welded and the wheel then be returned to service.

Answer 27

False; Never weld a cracked wheel.

Question 28

True or False: To prevent internal tire and wheel/rim damage air lines should be free of water and oil.

Answer 28

True.

Question 29

True or False: Wheel or rim Chording is used to describe flat spots on the wheel/rim edges.

Answer 29

True.

Question 30

True or False: Long tire life is only obtained by a joint effort between the operator and the service technician.

Answer 30

True.