NCED Transmission & Drivetrain Systems 4

Question 1

What is the function of the valve body in an automatic transmission?

Accepted Answer

It is a hydraulic control center that directs fluid to engage clutches and bands

Answer

The valve body routes pressurized transmission fluid through a network of passages and valves to activate the correct clutch packs and bands for each gear.

Question 2

A vibration felt in the vehicle at highway speeds that is NOT related to engine RPM is most likely caused by:

Accepted Answer

An imbalanced or damaged driveshaft

Answer

Driveshaft imbalance or damage produces a vehicle-speed-dependent vibration that does not change with engine RPM changes in the same gear.

Question 3

Which automatic transmission component prevents the engine from being used as a braking force in lower gears unless manually selected?

Accepted Answer

One-way (sprag) clutch or roller clutch

Answer

One-way clutches allow rotation in only one direction; they freewheel during engine braking unless a friction element overrides them in a manually selected lower range.

Question 4

The 'creep' behavior of a vehicle with an automatic transmission at idle in Drive is caused by:

Accepted Answer

Fluid coupling torque multiplication in the torque converter at low speeds

Answer

At idle, the torque converter still transmits some torque through fluid coupling, causing slight forward movement unless the brakes resist it.

Question 5

When replacing a clutch disc on a rear-wheel drive vehicle, technicians should also inspect the:

Accepted Answer

Flywheel or flexplate for wear, cracks, and heat spots

Answer

A worn clutch often glazes or damages the flywheel surface, which must be resurfaced or replaced to ensure the new clutch disc wears evenly.

(NCED) Nationally Certified Educational Diagnostician Practice Test

(NCED) Nationally Certified Educational Diagnostician Practice Test

NCED Transmission & Drivetrain Systems 4