Question 1

Which of the following methods of separating a U-joint from a driveshaft yoke when it is on the truck,is preferred?

Accepted Answer

A)  hydraulic jack on yoke hub 
B)  50 lb (25 kg)slide hammer on yoke 
C)  16 lb (7 kg)sledge hammer 
D)  two-jaw U-joint puller 
A)  hydraulic jack on yoke hub 
B)  50 lb (25 kg)slide hammer on yoke 
C)  16 lb (7 kg)sledge hammer 
D)  two-jaw U-joint puller D

Question 2

Which of the following operating conditions requires the most frequent lubrication of the driveshaft?

Accepted Answer

A)  4x4 vocational off-highway 
B)  pick-up and delivery 
C)  linehaul trucking 
D)  less-than-load 
A)  4x4 vocational off-highway 
B)  pick-up and delivery 
C)  linehaul trucking 
D)  less-than-load A

Question 3

All of the following conditions can cause driveshaft vibration EXCEPT:

Accepted Answer

A)  driveshaft out-of-balance 
B)  insufficient difference in U-joint operating angles 
C)  improper phasing 
D)  unequal U-joint working angles 
A)  driveshaft out-of-balance 
B)  insufficient difference in U-joint operating angles 
C)  improper phasing 
D)  unequal U-joint working angles B

Question 4

What is the function of the hanger bearing shim pack used between the bearing mount and the chassis crossmember?

Accepted Answer

A)  dampens chassis vibrations 
B)  dampens road shock 
C)  sets driveshaft angles 
D)  both A and B 
A)  dampens chassis vibrations 
B)  dampens road shock 
C)  sets driveshaft angles 
D)  both A and B

Question 5

What is usually considered to be the maximum recommended length for a single-piece driveshaft operating at speeds of 3,000 rpm?

Accepted Answer

A)  50 inches (127 centimeters) 
B)  70 inches (178 centimeters) 
C)  90 inches (228 centimeters) 
D)  95 inches (240 centimeters) 
A)  50 inches (127 centimeters) 
B)  70 inches (178 centimeters) 
C)  90 inches (228 centimeters) 
D)  95 inches (240 centimeters)

Question 6

Which of the following is recommended to be applied to the exterior of a set of U-joint bearing caps before installation into the yokes?

Accepted Answer

A)  never-seize compound 
B)  engine lube 
C)  chassis grease 
D)  silicone RTV compound 
A)  never-seize compound 
B)  engine lube 
C)  chassis grease 
D)  silicone RTV compound

Question 7

Technician A says that because PTO driveshafts are commonly driven at speeds lower than 1200 rpm,solid steel stock shafts can be used.Technician B says that because PTO driveshafts are used intermittently and at lower speeds,precision balancing is not usually required.Who is correct?

Accepted Answer

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

Question 8

What factors determine the required driveshaft diameter and wall thickness?

Accepted Answer

A)  maximum torque load 
B)  gross vehicle weight 
C)  type of operation 
D)  all of the above 
A)  maximum torque load 
B)  gross vehicle weight 
C)  type of operation 
D)  all of the above

Question 9

When attempting to dynamically balance a truck driveline,which of the following must be done?

Accepted Answer

A)  all the wheels must be off the ground 
B)  the frame must be level 
C)  the transmission and differential carrier must be at the same angle raised as on the ground 
D)  all of the above 
A)  all the wheels must be off the ground 
B)  the frame must be level 
C)  the transmission and differential carrier must be at the same angle raised as on the ground 
D)  all of the above

Question 10

What is usually regarded as the absolute maximum length a driveshaft should be without adding a center support bearing?

Accepted Answer

A)  70-inches (178 cm) 
B)  75-inches (190 cm) 
C)  80-inches (203 cm) 
D)  90-inches (228 cm) 
A)  70-inches (178 cm) 
B)  75-inches (190 cm) 
C)  80-inches (203 cm) 
D)  90-inches (228 cm)

Question 11

Technician A says that a driveshaft with U-joints speeds up and slows down once per rotation.Technician B says that to avoid torsional vibrations,the rear U-joint needs to cancel out the non-uniform rotation of the forward U-joint.Who is correct?

Accepted Answer

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

Question 12

If a driveshaft is assembled out-of-phase which of the following must have occured?

Accepted Answer

A)  U-joint assembled backward 
B)  transmission yoke has been changed 
C)  differential carrier yoke has been changed 
D)  driveshaft has been separated at the slip splines 
A)  U-joint assembled backward 
B)  transmission yoke has been changed 
C)  differential carrier yoke has been changed 
D)  driveshaft has been separated at the slip splines

Question 13

Which of the following are recommended lubricants for heavy-duty truck U-joints?

Accepted Answer

A)  lithium-based grease with EP additives 
B)  NLGI grade 1 or 2 grease 
C)  NLGI grade 3 or 4 grease 
D)  both A and B 
A)  lithium-based grease with EP additives 
B)  NLGI grade 1 or 2 grease 
C)  NLGI grade 3 or 4 grease 
D)  both A and B

Question 14

Which of the following describes a broken back driveline arrangement?

Accepted Answer

A)  working angles of its U-joints are equal 
B)  companion flanges or yokes are not parallel 
C)  both A and B 
D)  neither A nor B 
A)  working angles of its U-joints are equal 
B)  companion flanges or yokes are not parallel 
C)  both A and B 
D)  neither A nor B

Question 15

What is used on a driveline hanger bearing to buffer driveshaft vibrations and road shock?

Accepted Answer

A)  coaxial springs 
B)  rubber insulators 
C)  gusset braces 
D)  vertical springs 
A)  coaxial springs 
B)  rubber insulators 
C)  gusset braces 
D)  vertical springs

Question 16

When checking the dynamic balance of a truck driveshaft,an initial spin up indicates the balance is out.Which of the following should be performed FIRST before proceeding?

Accepted Answer

A)  remove any existing balance weights with a chisel 
B)  clamp one steel washer to the counterbalance position 
C)  remove the propeller shaft assembly 
D)  replace both the U-joints 
A)  remove any existing balance weights with a chisel 
B)  clamp one steel washer to the counterbalance position 
C)  remove the propeller shaft assembly 
D)  replace both the U-joints

Question 17

What instrument should be used to measure driveshaft runout?

Accepted Answer

A)  inclinometer 
B)  dial indicator 
C)  outside micrometer 
D)  bore gauge 
A)  inclinometer 
B)  dial indicator 
C)  outside micrometer 
D)  bore gauge

Question 18

Technician A says that driveshaft U-joints are expensive and engineered to last the life of the vehicle.Technician B says that replacing driveline propeller shaft assemblies is a common shop practice.Who is correct?

Accepted Answer

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

Question 19

What is the recommended tool used to measure the operating angles of driveline components?

Accepted Answer

A)  protractor 
B)  electronic inclinometer 
C)  balance sensor and strobe 
D)  carpenter's level 
A)  protractor 
B)  electronic inclinometer 
C)  balance sensor and strobe 
D)  carpenter's level

Question 20

When are the two universal joints on a driveshaft operating in-phase?

Accepted Answer

A)  transmission and rear axle are on the same horizontal plane 
B)  the two shaft sections are on the same vertical plane 
C)  the slip-yoke lugs and the tube-yoke lugs are aligned with each other 
D)  all of the above 
A)  transmission and rear axle are on the same horizontal plane 
B)  the two shaft sections are on the same vertical plane 
C)  the slip-yoke lugs and the tube-yoke lugs are aligned with each other 
D)  all of the above

Exam 22: Driveshaft Assemblies

Which of the following methods of separating a U-joint from a driveshaft yoke when it is on the truck,is preferred?

Which of the following operating conditions requires the most frequent lubrication of the driveshaft?

All of the following conditions can cause driveshaft vibration EXCEPT:

What is the function of the hanger bearing shim pack used between the bearing mount and the chassis crossmember?

What is usually considered to be the maximum recommended length for a single-piece driveshaft operating at speeds of 3,000 rpm?

Which of the following is recommended to be applied to the exterior of a set of U-joint bearing caps before installation into the yokes?

Technician A says that because PTO driveshafts are commonly driven at speeds lower than 1200 rpm,solid steel stock shafts can be used.Technician B says that because PTO driveshafts are used intermittently and at lower speeds,precision balancing is not usually required.Who is correct?

What factors determine the required driveshaft diameter and wall thickness?

When attempting to dynamically balance a truck driveline,which of the following must be done?

What is usually regarded as the absolute maximum length a driveshaft should be without adding a center support bearing?

Technician A says that a driveshaft with U-joints speeds up and slows down once per rotation.Technician B says that to avoid torsional vibrations,the rear U-joint needs to cancel out the non-uniform rotation of the forward U-joint.Who is correct?

If a driveshaft is assembled out-of-phase which of the following must have occured?

Which of the following are recommended lubricants for heavy-duty truck U-joints?

Which of the following describes a broken back driveline arrangement?

What is used on a driveline hanger bearing to buffer driveshaft vibrations and road shock?

When checking the dynamic balance of a truck driveshaft,an initial spin up indicates the balance is out.Which of the following should be performed FIRST before proceeding?

What instrument should be used to measure driveshaft runout?

Technician A says that driveshaft U-joints are expensive and engineered to last the life of the vehicle.Technician B says that replacing driveline propeller shaft assemblies is a common shop practice.Who is correct?

What is the recommended tool used to measure the operating angles of driveline components?

When are the two universal joints on a driveshaft operating in-phase?

Introduction to Servicing Heavy-Duty Trucks

Shop Safety and Operations

Tools and Fasteners

Preventive Maintenance Program

Fundamentals of Electricity

Fundamentals of Electronics and Computers

Batteries

Charging Systems

Cranking Systems

Chassis Electrical Circuits

Diagnosis and Repair of Electronic Circuits

Multiplexing

Hydraulics

Clutches

Standard Transmissions

Standard Transmission Servicing

Torque Converters

Automatic Transmissions

Automatic Transmission Maintenance

Electronically Automated Standard Transmissions

Electronically Controlled Automatic Transmissions Ecats

Heavy-Duty Truck Axles

Heavy-Duty Truck Axle Service and Repair

Steering and Alignment

Suspension Systems

Wheels and Tires

Truck Brake Systems

Hydraulic Brakes and Air-Over-Hydraulic Brake Systems

Abs and Ebs

Air Brake Servicing

Vehicle Chassis Frame

Heavy-Duty Truck Trailers

Fifth Wheels and Coupling Systems

Heavy-Duty Heating, ventilation, and Air Conditioning Systems

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