Heavy Duty Truck Systems – Chapter 22 – Lecture Summary & Practice Questions
U-joint failures, hanger bearing failures, and driveline vibrations are caused by: - correct answer
✔✔all the above
A truck driver complains of a driveline vibration. Technician A says that the problem might be a
loose drive shaft yoke. Technician B says that the problem could be worn splines in the slip joint.
Who is correct? - correct answer ✔✔both a and b
Which of the following would be least likely to affect drive shaft balance? - correct answer
✔✔missing U-joint zerk fitting
When lubricating a U-joint, fresh grease appears at all four trunnion seals. Which of the
following is probably true? - correct answer ✔✔The U-joint has been properly lubricated.
The OEM recommendation for U-joint lubrication interval scheduling on a truck used for an on-
highway operation should be: - correct answer ✔✔10,000 to 15,000
Technician A says that a drive shaft is in phase when assembled so that the yokes are 90 degrees
offset. Technician B says that drive shaft phasing will be altered by separating a drive shaft at the
slip joint and turning by one spline tooth. Who is correct? - correct answer ✔✔tech b only
Which of the following tools should be used to measure the inclination of a driveline
component? - correct answer ✔✔inclinometer
Technician A says that when lubricating a U-joint and grease does not exit from one of the four
trunnion seals, the U-joint must be immediately replaced. Technician B says that backing off the
bearing cap on a U-joint sometimes helps a trunnion to take grease. Who is correct? - correct
answer ✔✔tech b only
U-joint failures, hanger bearing failures, and driveline vibrations are caused by: - correct answer
✔✔all the above
A truck driver complains of a driveline vibration. Technician A says that the problem might be a
loose drive shaft yoke. Technician B says that the problem could be worn splines in the slip joint.
Who is correct? - correct answer ✔✔both a and b
Which of the following would be least likely to affect drive shaft balance? - correct answer
✔✔missing U-joint zerk fitting
When lubricating a U-joint, fresh grease appears at all four trunnion seals. Which of the
following is probably true? - correct answer ✔✔The U-joint has been properly lubricated.
The OEM recommendation for U-joint lubrication interval scheduling on a truck used for an on-
highway operation should be: - correct answer ✔✔10,000 to 15,000
Technician A says that a drive shaft is in phase when assembled so that the yokes are 90 degrees
offset. Technician B says that drive shaft phasing will be altered by separating a drive shaft at the
slip joint and turning by one spline tooth. Who is correct? - correct answer ✔✔tech b only
Which of the following tools should be used to measure the inclination of a driveline
component? - correct answer ✔✔inclinometer
Technician A says that when lubricating a U-joint and grease does not exit from one of the four
trunnion seals, the U-joint must be immediately replaced. Technician B says that backing off the
bearing cap on a U-joint sometimes helps a trunnion to take grease. Who is correct? - correct
answer ✔✔tech b only
