Deck 27: Wheels and Tires

Question 1

Which side of a truck equipped with stud-piloted disc wheels has left-hand thread lug nuts?

A) left
B) right side
C) both sides

Answer 1

A

Question 2

Which of the following statements about truck wheel ends is true?

A) a tire is mounted to a rim,and the rim is mounted to a wheel
B) a tire is mounted to a wheel,which is supported by the rim
C) a wheel is mounted to a rim,and the brakes are mounted to a spindle
D) a wheel is mounted to a spider,and the brakes are mounted to a rim

Answer 2

A

Question 3

Which of the following procedures is BEST practice for removing a bearing race from an aluminum hub?

A) drive out using a pneumatic hammer and steel drift
B) drive out using a rubber hammer and brass drift
C) preheat the hub in a thermostatically controlled oven and tap out with a steel drift
D) preheat the hub with an acetylene torch and drive out with a pneumatic hammer

Answer 3

C

Question 4

Which of the following safety precautions should be adhered to when inflating truck tires?

A) inflate tires in a safety cage
B) use a clip-on chuck with a remote in-line valve
C) stay out of the trajectory of any parts that could separate
D) all of the above

Question 5

When torquing the rim lug (clamp)nuts on a truck cast spoke wheel,which of the following should be true about the method,torque sequence,and position you torque each nut?

A) wheel down,circular torque sequence,torque each nut at 12 o'clock
B) wheel down,criss-cross torque sequence,torque each nut at 6 o'clock
C) wheel up,criss-cross torque sequence,torque each nut at 12 o'clock
D) wheel up,circular torque sequence,torque each nut at 6 o'clock

Question 6

If a truck is carrying 20% more weight than it was spec'd for,how much should tire pressures be increased to compensate?

A) additional 20%
B) reduce by 20% to increase footprint
C) over-inflation does not compensate for overloads
D) none of the above

Question 7

A tire used on a truck rear axle has premature wear at both wall sides of the treads.What is the most likely cause?

A) overinflation
B) underinflation
C) excess toe
D) excess caster

Question 8

What is the maximum permitted runout for a truck cast spoke wheel after adjustment?

A) 1/16" (1.5 mm)
B) 1/8" (3 mm)
C) 3/16" (4.5 mm)
D) 1/4" (6 mm)

Question 9

What is said to be the number one cause of tire blow-outs?

A) under-inflation
B) over-inflation
C) puncture by road debris
D) overloading

Question 10

At what point should a tire be deflated when it going to be replaced?

A) before removing it from the truck wheel
B) immediately after removing it from the wheel
C) just before removing a split rim
D) just before breaking the bead

Question 11

If a truck is spec'd for minimum weight,optimum fuel economy and the lowest unsprung weight,which type of wheel would probably be used?

A) cast spoke
B) wide-base,aluminum singles
C) stud-piloted steel dual discs
D) hub-piloted steel dual discs

Question 12

When matching tires on a tandem drive axle truck with dual wheels which of the following should be true?

A) drive lugs should never be retreaded
B) radials can only be put on the front drive axle
C) all eight drive axle tires should match in nominal size and type of construction
D) tires are of different construction,must be matched in nominal size

Question 13

Which of the following is the more likely cause of tires that wear fast and fail prematurely?

A) overloading
B) poor quality
C) lack of maintenance
D) poorly surfaced interstates

Question 14

According to Federal Motor Carrier safety regulations,at what thread depth should front axle steering tires be replaced?

A) 2/32" (1.5 mm)
B) 3/32" (2 mm)
C) 4/32" (3 mm)
D) when the wear indicators show

Question 15

Which of the following correctly describes how most commercial highway truck wheel bearings are lubricated?

A) factory-lubricated for life,sealed bearings
B) wet (oil bath)hub
C) all purpose axle grease
D) graphite-base multi-purpose grease

Question 16

Which of the following is a typical tire cold inflation pressure of a heavy-duty truck radial tire?

A) 30 psi (206 kPa)
B) 35 psi (241 kPa)
C) 100 psi (690 kPa)
D) 140 psi (893 kPa)

Question 17

Which of the following are differences between truck radial and bias-ply tires?

A) tread profile
B) handling characteristics
C) dynamic footprint
D) all of the above

Question 18

Which of the following wheel types would be preferred in an application where maximum load capacity and rough terrain are considerations when spec'ing a truck?

A) cast spoke
B) hub-piloted disc
C) stud-piloted disc
D) aluminum alloy disc

Question 19

What are said to be the two biggest cost factors in operating a truck?

A) fuel is first,followed by tires
B) tires are first,followed by fuel
C) tires are first,followed by brakes
D) brakes are first,followed by tires

Question 20

When checking a set of duals for adequate spacing between them,which specific location MUST be checked?

A) 6 o'clock position
B) 12 o'clock position
C) both the 3 and 9 o'clock positions
D) both the 10 and 4 o'clock positions

Question 21

Which of the following is true regarding an 18-wheeler?

A) it has 9-axles
B) it has a total of 18 wheels
C) it has a total of 18 tires
D) it has a total of 6-axles

Question 22

Technician A says that disc wheels nuts and studs on the left side of a truck often use a right hand thread.Technician B says that disc wheels often use fasteners that unscrew in the reverse of their direction of forward rotation.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 23

Technician A says that in a cast spoke wheel,the wheel hub is integral with wheel.Technician B says that in disc wheels,the wheel hub and wheel are a single unit.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 24

Technician A says that tire pressures should always be checked when the tires are at operating temperature.Technician B says that the pressure rise that takes place from a cold tire to one at operating temperature is usually around 10% in a truck tire.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 25

What does the term 18-wheeler refer to?

A) any transport truck
B) single drive axle tractor and dual axle trailer
C) dual drive axle tractor and dual axle trailer
D) dual drive axle tractor and B-train combination

Question 26

When a tire is over-inflated,where is accelerated wear going to take place?

A) center of treads
B) side of treads
C) sidewall
D) bead

Question 27

Technician A says that you cannot mix bias ply and radial tires on a steering axle.Technician B says that it is OK to mix bias ply and radial on a truck drive axle providing you do not mismatch the dual pairs.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 28

If you replaced all the duals on an 18-wheeler with wide-base singles,how many tires would the rig have?

A) 8
B) 10
C) 12
D) 14

Question 29

Technician A says that OSHA requires any technician to have training before working on tires mounted with split rims.Technician B says that large numbers of trashed tires represent a major fire hazard and most jurisdictions have tire disposal regulations.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 30

Technician A says that radial tires deflect less than bias ply tires when operating under load and at highway speeds.Technician B says that radial tires have a constantly changing footprint in operation.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 31

Technician A says that to deflate a truck tire,the Schrader valve plunger should be depressed until all of the air pressure is relieved.Technician B says that a Shrader valve is the only common component in vehicles ranging from a bicycle through automobiles and highway trucks.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 32

Technician A says that steer axle tires are required to have at least 3/32-inch (2 mm)of tread groove depth.Technician B says that a trailer tire with 2/32-inch (1.5 mm)groove depth is just legal.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 33

When tire section height (tread center to bead plane)is divided by its section width (sidewall to sidewall),the result is known as:

A) tire nominal size
B) rolling radius
C) aspect ratio
D) circumference

Question 34

Technician A says that to cure a cracked rim that is leaking air out of tires,an inner tube should be installed.Technician B says that a cracked rim can be repaired by welding using an E-7018 electrode.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 35

Which of the following heavy truck wheel types would be best suited to a harsh,construction site environment?

A) cast spoke
B) stud-piloted disc
C) hub-piloted disc
D) aluminum disc

Question 36

Which of the following is a major advantage of a cast spoke wheel when compared with a stud-piloted disc wheel?

A) lighter weight
B) fewer wheel-off incidents
C) fewer runout problems
D) all of the above

Question 37

Technician A says that cast spoke wheels for heavy duty trucks are cast with 3,4,or 6 spokes.Technician B says that a cast spoke wheel with 6 spokes is most likely to be found on a heavily loaded front axle.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 38

Which of the following tire sizes would you expect to find on a Class 8 highway truck?

A) 18- or 20-inch (45 or 50 cm)
B) 22.5- or 24.5-inch (57 or 62 cm)
C) 23- or 25-inch (58 or 64 cm)
D) 26.5- or 28.5-inch (67 or 72 cm)

Question 39

What is a common cause of a flat spot on a steer axle tire?

A) parking on hot asphalt
B) kingpin wear
C) excessive toe-in
D) aggressive braking

Question 40

Which of the following are advantages of hub-piloted truck disc wheels when compared with cast spoke wheels?

A) fewer alignment problems
B) lighter weight
C) extended tire life
D) all of the above

Question 41

What method should be used to adjust wheel bearings on all non-unitized wheel hubs?

A) air gun method
B) Johnson bar method
C) 4 X 4 method
D) TMC method

Question 42

What is the torque required for wheel installation in a ConMet unitized hub system?

A) none used
B) 150 lb-ft (203 N.m)
C) 300 lb-ft (407 N.m)
D) 450 lb-ft (610 N.m)

Question 43

Technician A says that all tires of the same nominal diameter have the same rolling radius.Technician B says that to determine the rolling radius of a truck tire to measure the periphery using a tape measure and divide the result into one mile.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 44

What is used on a tire tread profile to minimize river erosion during operation on wet pavement?

A) unidirectional grooves
B) lugs
C) wear indicators
D) sipes

Question 45

Technician A says that it is only necessary to balance axle wheel ends on the steer axle of a highway rig.Technician B says that out-of-balance axle ends substantially reduce tire life.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 46

Technician A says that the wheel bearing on a unitized hub system should not require adjustment during the life of the hub.Technician B says that periodic topping up of oil in wheel hubs is eliminated in some types of unitized axle.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 47

What types of spacer ring can be used on truck cast spoke wheel assemblies?

A) channel
B) corrugated
C) corrugated channel
D) all of the above

Question 48

What percentage increase in fuel efficiency is claimed when all of the dual tires on a typical semi-combination rig are replaced with wide-base singles?

A) 2 to 5%
B) 5 to 8%
C) 7 to 9%
D) 8 to 10%

Question 49

Technician A says that modern tires are engineered to be retreaded just once during their service life.Technician B says that the cost of retreading a typical truck tire is approximately 50% of the cost of a new tire.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 50

Technician A says that after replacing the drive axle tires on a highway tractor,the new revolutions per mile data must be programmed to the chassis data bus.Technician B says that the previous programming data is still valid providing the tires are of the same nominal dimension.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 51

When using the TMC recommended practice (RP 618A)method of setting bearing endplay on commercial truck wheel ends,what is the first step torque setting usually specified as?

A) 50 lb-ft (68 N.m)
B) 200 lb-ft (270 N.m)
C) 400 lb-ft (540 N.m)
D) 600 lb-ft (810 N.m)

Question 52

A truck tire is resisting seating at the bead.Technician A says that a metal ring inflation aid and compressed air should be used.Technician B says that a shot of ether and a match should do the trick.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 53

Technician A says that automatic tire pressure control systems (TPCS)can often pay for themselves during the life of a truck due to reduced tire costs.Technician B says that TPCS systems must be spec'd to new truck and may not be retrofit to current trucks.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 54

Technician A says that a truck wheel that is just a couple of ounces out of balance can result in an uncomfortable ride and vibration.Technician B says that the centrifugal thrust created by an out-of-balance tire is neutralized when the tire is loaded.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 55

Technician A says that the mass (weight)of a truck axle end includes the all of the components that rotate.Technician B says that is not necessary to balance truck wheel ends because the manufacturing process ensures that new truck tires are already balanced.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 56

After completing a TMC wheel end adjustment which of the following confirms that the adjustment is as specified?

A) preload drag of 5-inch pounds (0.56 N.m)measured with fishscale
B) preload drag of 5-foot pounds (7 N.m)measured with torque wrench
C) endplay of 0.001-inch to 0.005-inch (0.025 to 0.127 mm)measured with a dial indicator
D) endplay within 0.010-inch (0.254 mm)measured with a dial indicator

Question 57

What tool(s)should be used to install a typical truck wheel seal?

A) seal driver and hammer
B) bearing driver and hammer
C) flat faced punch and hammer
D) seal driver and hydraulic press

Question 58

Which of the following methods should be used to check wheel runout on a mounted tire?

A) dial indicator
B) wood block and chalk
C) brake drum micrometer
D) computerized alignment deck

Question 59

When mounting a set of duals to a cast spoke wheel,where should the spacer ring be placed?

A) inside the inboard tire
B) outside the outboard tire
C) does not matter so long as it is installed
D) between the inboard and outboard tires

Question 60

Technician A says that dynamic balancing of axle ends has been proven to improve fuel economy.Technician B says that dynamic balancing of wheel ends reduces suspension maintenance costs.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 61

Technician A says that an advantage of nitrogen filled tires is that tire life is extended because both oxygen and moisture are eliminated from the tire.Technician B says that an advantage of nitrogen filled tires is that tire pressures are less responsive to changes in temperature and maintain a more constant pressure.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 62

What is a common cause of repeated shock absorber failures on a trailer with an air suspension?

A) poor quality shocks
B) improper leveling valve ride height
C) wheel ends out-of-balance
D) overloading

Question 63

Technician A says that spin balancing is an effective method of balancing axle ends.Technician B says that using an internal balancing agent (IBA)is an effective and cost-effective means of balancing wheel ends.Who is correct?

A) Technician A only
B) Technician B only
C) Both A and B
D) Neither A nor B

Question 64

What should be done to a tire on a truck when its pressure is tested to be less than 50 psi of its specified value?

A) Inflate it to specification on the truck
B) Remove the tire,and place it in a safety cage for assessment
C) Discard the tire and replace with a new one
D) Locate the leak and insert a plug

Question 65

What is regarded as a cost-effective means of easily identifying wheel lug nuts that are loosening?

A) lug nut indicators
B) checking to see if they can be unscrewed by hand
C) re-torquing each lug nut during the driver pre-trip inspection
D) using a chalk mark on each lug hex flat