310T Drivetrain and Transmission 2

Question 1

A Class 8 truck exhibits a harsh 1-2 upshift in an Allison automatic transmission. What is the MOST likely cause?

Accepted Answer

Faulty turbine speed sensor

Answer

A faulty turbine speed sensor provides incorrect shaft speed data, causing the TCM to miscalculate shift timing and produce harsh upshifts.

Question 2

When performing a stall test on a torque converter, what does a stall speed BELOW the manufacturer's specification indicate?

Accepted Answer

Low engine power or a seized stator

Answer

A stall speed below spec indicates the engine cannot develop enough power, or the stator is seized and is not allowing proper fluid coupling multiplication.

Question 3

Which component in a standard Spicer-style driveshaft prevents vibration caused by the angularity of universal joints?

Accepted Answer

Phased yokes

Answer

Phased (timed) yokes ensure the front and rear U-joints operate in the same plane, canceling out speed fluctuations and preventing driveline vibration.

Question 4

A truck technician is diagnosing a manual transmission that pops out of fifth gear under load. What is the MOST probable cause?

Accepted Answer

Worn detent balls and springs

Answer

Worn detent balls and springs cannot hold the shift rail in the selected gear position, allowing the transmission to pop out under load.

Question 5

In a tandem drive axle bogie, what is the purpose of the interaxle differential lock?

Accepted Answer

It couples both axle input shafts to distribute torque equally regardless of traction

Answer

The interaxle differential lock mechanically couples the forward and rear drive axle inputs so torque is equally distributed, preventing one axle from spinning freely when traction is lost.

(310t) Truck and Coach Technician Certification Practice Test

(310t) Truck and Coach Technician Certification Practice Test

310T Drivetrain and Transmission 2