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HEAVY TRUCK DRIVELINE ANGLES Michigan Mechanic Exam
– Original Questions with Answers and Rationales
Section 1: Driveline Fundamentals (Questions)
1. What is the primary function of the driveline on a heavy
truck?
A. To steer the vehicle
B. To transmit torque from the transmission to the drive
axle(s)
C. To support the vehicle weight
D. To absorb road shocks
Answer: B
Rationale: The driveline (driveshaft, U-joints, slip yoke,
carrier bearing) transfers engine torque from the
transmission output to the differential, allowing the
wheels to turn.
2. Which component allows the driveshaft to change length
as the suspension moves?
A. U-joint
B. Slip yoke or slip joint
C. Carrier bearing
D. Pinion flange
Answer: B
Rationale: The slip yoke (or slip joint) slides in and out of
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the transmission or a splined stub shaft, accommodating
changes in driveshaft length caused by suspension travel.
3. What is the purpose of the universal joint (U-joint)?
A. To reduce vibration
B. To allow the driveshaft to transmit power at varying
angles
C. To connect the driveshaft to the frame
D. To absorb torque spikes
Answer: B
Rationale: U-joints permit the driveshaft to transmit
torque even when the transmission output shaft and the
axle pinion shaft are not perfectly aligned, allowing for
angular movement.
4. A two-piece driveshaft typically uses which component to
support the center?
A. Slip yoke
B. Center (carrier) bearing
C. U-joint only
D. Flange yoke
Answer: B
Rationale: A two-piece driveshaft has a center support
bearing (carrier bearing) mounted to the frame, which
supports the middle of the shaft and reduces vibration in
long-wheelbase vehicles.
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5. The angle between the transmission output shaft and the
driveshaft is called the:
A. Pinion angle
B. Operating angle of the front U-joint
C. Slip angle
D. Caster angle
Answer: B
Rationale: The operating angle is the angle between the
centerlines of the two shafts connected by a U-joint. At
the front, it's between the transmission output and the
driveshaft.
6. The angle between the driveshaft and the axle pinion shaft
is called the:
A. Front operating angle
B. Rear operating angle
C. Driveshaft angle
D. Thrust angle
Answer: B
Rationale: The rear operating angle is the angle between
the driveshaft centerline and the differential pinion shaft
centerline at the rear U-joint.
7. What is the ideal relationship between the front and rear
U-joint operating angles on a one-piece driveshaft?
A. They should be equal and opposite (cancel each other)
HEAVY TRUCK DRIVELINE ANGLES Michigan Mechanic Exam
– Original Questions with Answers and Rationales
Section 1: Driveline Fundamentals (Questions)
1. What is the primary function of the driveline on a heavy
truck?
A. To steer the vehicle
B. To transmit torque from the transmission to the drive
axle(s)
C. To support the vehicle weight
D. To absorb road shocks
Answer: B
Rationale: The driveline (driveshaft, U-joints, slip yoke,
carrier bearing) transfers engine torque from the
transmission output to the differential, allowing the
wheels to turn.
2. Which component allows the driveshaft to change length
as the suspension moves?
A. U-joint
B. Slip yoke or slip joint
C. Carrier bearing
D. Pinion flange
Answer: B
Rationale: The slip yoke (or slip joint) slides in and out of
,https://www.stuvia.com/user/performance
the transmission or a splined stub shaft, accommodating
changes in driveshaft length caused by suspension travel.
3. What is the purpose of the universal joint (U-joint)?
A. To reduce vibration
B. To allow the driveshaft to transmit power at varying
angles
C. To connect the driveshaft to the frame
D. To absorb torque spikes
Answer: B
Rationale: U-joints permit the driveshaft to transmit
torque even when the transmission output shaft and the
axle pinion shaft are not perfectly aligned, allowing for
angular movement.
4. A two-piece driveshaft typically uses which component to
support the center?
A. Slip yoke
B. Center (carrier) bearing
C. U-joint only
D. Flange yoke
Answer: B
Rationale: A two-piece driveshaft has a center support
bearing (carrier bearing) mounted to the frame, which
supports the middle of the shaft and reduces vibration in
long-wheelbase vehicles.
, https://www.stuvia.com/user/performance
5. The angle between the transmission output shaft and the
driveshaft is called the:
A. Pinion angle
B. Operating angle of the front U-joint
C. Slip angle
D. Caster angle
Answer: B
Rationale: The operating angle is the angle between the
centerlines of the two shafts connected by a U-joint. At
the front, it's between the transmission output and the
driveshaft.
6. The angle between the driveshaft and the axle pinion shaft
is called the:
A. Front operating angle
B. Rear operating angle
C. Driveshaft angle
D. Thrust angle
Answer: B
Rationale: The rear operating angle is the angle between
the driveshaft centerline and the differential pinion shaft
centerline at the rear U-joint.
7. What is the ideal relationship between the front and rear
U-joint operating angles on a one-piece driveshaft?
A. They should be equal and opposite (cancel each other)
