ASE Manual Drive Train and Axles Flashcards
6 cards from real ASE practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 6 ASE Manual Drive Train and Axles flashcards as text
A rear-axle differential makes a howling noise that changes pitch with vehicle speed but not with engine speed. What is the MOST likely cause?
Answer: Improper ring and pinion gear backlash or worn gear teeth
A howl that tracks vehicle speed rather than engine speed is characteristic of ring and pinion gear noise from improper backlash, wear, or incorrect contact pattern.
When setting up a ring and pinion gear set in a rear axle, what does the gear tooth contact pattern indicate?
Answer: The correct pinion depth and backlash adjustment
The contact pattern (checked with gear marking compound) shows whether pinion depth and backlash are set correctly for quiet, durable gear operation.
A 4WD vehicle with an open differential on the rear axle gets stuck with one wheel spinning freely. What limited-slip or locking device would MOST effectively prevent this?
Answer: Positraction or limited-slip differential
A limited-slip or locking differential transfers torque to the wheel with traction rather than allowing all torque to go to the spinning wheel.
What fluid is typically required in a limited-slip differential, and why?
Answer: Gear oil with a limited-slip friction modifier additive to prevent chatter
Limited-slip differentials use clutch packs that require a friction modifier to control the coefficient of friction and prevent the shudder or chatter that occurs with standard gear oil.
A technician measures excessive axle shaft endplay on a semi-floating rear axle. What is the MOST likely cause?
Answer: Worn axle bearing
On a semi-floating axle, the axle bearing supports the axle and controls endplay; a worn bearing allows the axle to move axially beyond specification.
What is the CORRECT method to check differential bearing preload?
Answer: Measure the torque required to rotate the pinion with a inch-pound torque wrench
Pinion bearing preload is measured as rotating torque (in inch-pounds) using a torque wrench and socket on the pinion nut after the crush sleeve is set.