Automatic Transmission/Transaxle Flashcards

A stall test that produces RPM well above specification indicates which problem?

Answer: Clutch or band slippage

Higher-than-spec stall RPM means the apply components are slipping and not transmitting full torque.

A stall test RPM that is far below specification most likely points to which condition?

Answer: Engine not producing full power

Below-spec stall RPM usually means the engine cannot reach full torque output, not a transmission fault.

What is the primary purpose of the torque converter stator?

Answer: Multiply torque at low speed

The stator redirects fluid back to the impeller, multiplying torque during acceleration.

Delayed engagement when shifting from Park to Drive after the car sits overnight most likely indicates what?

Answer: Leaking pump or valve body allowing fluid drainback

Internal leakage drains pressure overnight, so it takes time to refill and engage when started.

Which device on older transmissions senses vehicle speed hydraulically to help control upshifts?

Answer: Governor

The hydraulic governor develops pressure proportional to output shaft speed to signal upshifts.

A vacuum modulator with a ruptured diaphragm will most likely cause which symptom?

Answer: Transmission drawing fluid into the intake / smoking exhaust

A torn modulator diaphragm lets engine vacuum pull ATF into the intake manifold, causing smoke.

What is the function of an accumulator in an automatic transmission?

Answer: Cushion clutch and band apply for smooth shifts

The accumulator absorbs a portion of apply pressure to soften the shift feel.