310T Drive Train Systems 2

Question 1

A heavy-duty truck experiences a vibration that increases with vehicle speed but is NOT affected by engine RPM. The MOST likely cause is:

Accepted Answer

Driveshaft imbalance or worn U-joints

Answer

A speed-related vibration independent of engine RPM points to the driveshaft or U-joints rather than engine components.

Question 2

Which type of differential is BEST suited for a drive axle that regularly operates on slippery surfaces?

Accepted Answer

Limited-slip differential

Answer

A limited-slip differential transfers more torque to the wheel with better traction, improving performance on slippery surfaces.

Question 3

When checking driveshaft working angles, the front and rear U-joint angles should be:

Accepted Answer

Equal and in opposite phase

Answer

Equal but opposing working angles cancel out velocity fluctuations and prevent vibration in the driveline.

Question 4

A manual transmission jumps out of a high gear under load. The MOST probable cause is:

Accepted Answer

Worn shift fork or detent springs

Answer

Worn shift forks or weak detent springs allow the synchronizer sleeve to slide back out of engagement under load.

Question 5

In a tandem drive axle arrangement, the purpose of the inter-axle differential (power divider) is to:

Accepted Answer

Distribute torque equally between the front and rear drive axles

Answer

The inter-axle differential allows the two drive axles to rotate at different speeds while splitting torque between them.

(310t) Truck and Coach Technician Certification Practice Test