Transmission & Drivetrain Systems Flashcards
7 cards from real CPT practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Transmission & Drivetrain Systems flashcards as text
What is the primary function of the differential in a drivetrain?
Answer: Allow the drive wheels to rotate at different speeds during cornering
The differential allows the inner and outer drive wheels to rotate at different speeds during turns, preventing tire scrub and maintaining vehicle control.
In a rear-wheel-drive vehicle, what is the purpose of the universal joint (U-joint) on the driveshaft?
Answer: Transmit torque through angles between non-aligned shafts
U-joints allow the driveshaft to transmit torque at an angle, accommodating the angular difference between the transmission output and the differential pinion.
A worn or damaged U-joint typically produces what symptom?
Answer: Vibration that increases with vehicle speed, often felt as a clunk on acceleration or deceleration
A worn U-joint creates vibration at speed and a characteristic clunk when transitioning between acceleration and engine braking as the worn joint binds.
What is the function of a Constant Velocity (CV) joint compared to a standard U-joint?
Answer: CV joints deliver smooth power at greater angles without speed fluctuations
CV joints maintain a constant output speed even at large operating angles, eliminating the velocity fluctuations that cause vibration in standard U-joints at high angles.
What symptom is most characteristic of a worn outer CV joint boot that has failed and lost its grease?
Answer: Clicking or popping noise during low-speed turns
A dry, worn outer CV joint produces a clicking or popping noise during low-speed turns because the joint angle is greatest when turning, loading the worn, dry joint.
In a four-wheel-drive (4WD) system, what is the role of the transfer case?
Answer: Split and distribute engine torque between the front and rear axles
The transfer case receives power from the transmission and splits it between the front and rear driveshafts, enabling all four wheels to be driven.
What is the difference between a limited-slip differential (LSD) and an open differential?
Answer: An LSD transfers some torque to the higher-traction wheel when one wheel spins
Unlike an open differential that sends most torque to the slipping wheel, an LSD uses clutches or cams to bias torque toward the wheel with greater traction.