Your FREE ASE A2 Flashcards 2026 – 200+ Cards

A fluid coupling between the engine and transmission that multiplies engine torque at low speed and contains a lock-up clutch for direct drive at cruise.

A clutch inside the torque converter that mechanically couples the impeller to the turbine, eliminating slip to improve fuel economy at cruising speed.

The torque converter element driven by the engine that flings fluid outward to drive the turbine.

The torque converter element connected to the transmission input shaft; fluid from the impeller spins it to transmit power.

The torque converter element that redirects returning fluid to multiply torque; it rides on a one-way clutch.

An overrunning clutch that holds the stator during torque multiplication and lets it freewheel at the coupling point.

A gear arrangement of a sun gear, planet pinions on a carrier, and a ring gear that provides the transmission's forward, reverse, and reduction ratios.

The central gear of a planetary gearset; holding or driving it produces different gear ratios.

The outer internally toothed gear of a planetary set that meshes with the planet pinions.

The member that holds the planet pinions; output through the carrier yields gear reduction.

The hydraulic control center of the transmission, containing valves and passages that route fluid pressure to apply clutches and bands for shifts.

An electrically operated valve that the TCM/PCM uses to direct hydraulic pressure for automatic up- and downshifts.

A solenoid that varies line pressure electronically based on throttle load and torque to control shift feel and clutch apply.

The base hydraulic pressure produced by the pump and regulated by the pressure regulator valve; it supplies all apply circuits.

The valve that sets line pressure by bleeding off excess pump output back to the sump or converter circuit.

In hydraulically controlled transmissions, a road-speed-proportional pressure that helps schedule upshifts (replaced by VSS data in electronic units).

A pressure proportional to engine load used in older transmissions to delay shifts under acceleration; modern units use throttle-position sensor data.

A diagnostic that holds the brakes and briefly applies full throttle in gear to read converter stall speed, checking the converter and clutch/band holding capacity.

The maximum engine rpm reached during a stall test; high or low readings point to converter, clutch, or band problems.

Connecting a gauge to a test port to measure line and circuit pressures and compare them against specification across gear ranges.

Applying regulated shop air to valve-body circuits to confirm a clutch or band applies, isolating hydraulic versus mechanical faults.

A controlled drive that checks shift timing, quality, slip, harshness, and noise through all ranges to characterize a complaint.

The smoothness and timing of a gear change; harsh, slipping, or delayed shifts indicate pressure, clutch, or control faults.

A condition where engine rpm rises without a matching increase in vehicle speed, caused by worn clutches/bands, low fluid, or low pressure.

A momentary rpm rise during a shift caused by one element releasing before the next applies; a sign of worn clutches or low pressure.

An abrupt, firm shift or Park-to-Drive engagement, often from high line pressure, a faulty EPC solenoid, or a converter fault.

A lag between selecting a gear and the vehicle moving, commonly from low fluid, internal leaks, worn pump, or worn clutch seals.

A vibration felt during torque-converter lock-up apply, frequently caused by contaminated fluid or a worn lock-up clutch.

ATF that is dark and smells burnt, indicating overheated, slipping friction material and likely internal clutch/band damage.

ATF that is pink and milky from coolant or water contamination, often a failed transmission cooler in the radiator.

A protective strategy where the TCM locks the transmission into one gear after detecting an electronic fault to allow limited driving.

A stored code the TCM/PCM sets when an input or output is out of range, retrieved with a scan tool to direct diagnosis.

A device that reads DTCs, live data, and bidirectional commands from the transmission controller to verify sensors and actuators.

The computer that monitors sensors and operates shift solenoids to control shift timing, pressure, and converter lock-up.

A sensor that reports output/road speed to the TCM for shift scheduling and speedometer operation.

A sensor measuring input shaft speed; comparing it to output speed lets the TCM detect slip and control shift feel.

A switch/sensor that tells the controller which gear range the shifter selects and enables starter only in Park/Neutral.

A thermistor that reports ATF temperature so the TCM can adjust line pressure, lock-up, and overheat protection.

A sensor of throttle/load the TCM uses to schedule shift points and shift firmness.

The valve in the valve body moved directly by the gear selector linkage to route pressure for the chosen range.

A spring-and-piston device that cushions clutch/band apply for smoother shifts by temporarily absorbing apply pressure.

A hydraulic piston that applies a band when fed apply pressure from the valve body.

A friction-lined steel strap that wraps and holds a drum stationary to provide a reaction member for certain gears.

Alternating friction and steel plates that lock rotating members together when apply pressure compresses them.

A mechanical clutch that drives in one direction and freewheels in the other, providing automatic holding for certain gears.

A condition where the vehicle will not move in any range, often from low fluid, a failed pump, broken input shaft, or stripped splines.

Loss of reverse only, usually a specific clutch/band, servo, or valve-body circuit dedicated to reverse.

Random or repeated shifting between gears, commonly from a faulty speed sensor, solenoid, or internal leak.

Shudder only during lock-up apply points to the converter clutch; shudder under load in any gear points to the engine.

Internal fluid leakage between circuits past worn seals or a warped valve body that causes slipping or wrong gear apply.

A combined transmission and final-drive/differential in one housing, used in front-wheel-drive and some rear/mid-engine vehicles.

Pressure applied to a confined fluid acts equally in all directions, the basis for transmission clutch and band apply.

The converter's ability to increase engine torque at low turbine speed thanks to the stator redirecting fluid.

The speed at which turbine nearly matches impeller, torque multiplication ends, and the converter acts as a fluid coupling.

Older transmissions schedule shifts purely with governor/TV pressure; modern units use the TCM, sensors, and solenoids.

A transmission using a belt or chain between variable-diameter pulleys to provide infinite ratios rather than fixed gears.

A forced downshift commanded by full or near-full throttle to provide acceleration, via cable, switch, or TPS.

Selecting a low range to hold a lower gear for engine braking or grade climbing instead of allowing automatic upshifts.

A torque converter operating without multiplication, transmitting power as a simple fluid coupling near the coupling point.

The Park-to-Drive or Park-to-Reverse engagement; harshness or delay here is a key diagnostic symptom.

A jolt selecting a gear, from high line pressure, worn mounts, excessive driveline lash, or a faulty EPC solenoid.

Excessive ATF temperature from heavy towing, low fluid, slipping, or a blocked cooler that rapidly degrades fluid and friction material.

A speed-sensitive valve in hydraulic transmissions that generates road-speed-based pressure to schedule upshifts.

A valve that, at wide-open throttle, signals a downshift for passing in hydraulically controlled units.

A vacuum-operated device on older transmissions that adjusts shift pressure with engine load via manifold vacuum.

Checking for ATF in the vacuum line, which indicates a ruptured modulator diaphragm drawing fluid into the intake.

Line pressure increasing with throttle/torque so clutches hold under load; failure to rise causes slip under acceleration.

The TCM commanding lock-up on and off based on speed, load, and temperature; faults cause stall, shudder, or poor economy.

Limiting each stall test to a few seconds and watching temperature to avoid overheating the converter and fluid.

The TCM inhibiting lock-up or reducing load when fluid temperature is too high or too low for proper operation.

The ASE Automatic Transmission/Transaxle test for automotive technicians, part of the Automobile (A-series) certification.

ASE certifications are valid for five years; technicians must pass a recertification test to maintain credentials.

Trial questions mixed into an ASE test that gather statistics and do not count toward the score.

The A2 test contains roughly 50 questions, with about 45 scored items distributed across the content areas.

An ASE question format where two technicians make statements and you decide which one(s) are correct.

The specific apply device for reverse; its failure causes loss of reverse while forward gears remain.

Starting in a high gear due to a failsafe or solenoid fault, producing sluggish, slipping launch.

Repeated small shifts or torque-converter cycling, often from a marginal speed sensor, solenoid, or low fluid.

Measuring a solenoid's coil resistance against spec to confirm it is electrically sound before condemning the valve body.

Checking the transmission's external harness and case connector for corrosion or opens that mimic internal electronic faults.

Verifying clean power and ground to the TCM and solenoids, since high resistance can cause erratic, code-setting behavior.

Hydraulic and electronic features that prevent reverse engagement above a set speed to protect the geartrain.

The TCM comparing input and output speed to compute converter or clutch slip and detect early failure.

Improper stator one-way clutch operation: seized stator causes poor high-speed performance; freewheeling stator causes weak acceleration.

A specialized hydraulic oil that transmits power, cools, lubricates, and provides correct friction for clutches and bands.

The exact fluid type a transmission requires (such as DEXRON, MERCON, or a CVT/DCT fluid); using the wrong fluid causes shift faults and damage.

Verifying ATF level, usually at operating temperature on a level surface with the engine running and selector cycled, per the service procedure.

ATF expands with heat, so the dipstick has separate hot and cold ranges; reading at the wrong temperature gives a false level.

Judging ATF by color and smell: bright red is good; brown/burnt signals overheating; milky signals coolant contamination.

Draining and refilling ATF and replacing the filter at the service interval to remove worn friction material and restore additives.

A machine procedure that exchanges nearly all old fluid; only appropriate when the manufacturer approves it for that unit.

A screen or media filter on the pump pickup that removes debris; replaced during a fluid/pan service.

The bottom cover that holds reserve fluid; debris in the pan (metal, clutch material) is a key diagnostic clue.

The seal between the pan and case; replaced during service and torqued evenly to prevent leaks.

A magnet in the pan that collects ferrous wear particles; heavy steel debris indicates internal gear or bearing failure.

A heat exchanger (in the radiator or a separate cooler) that removes heat from ATF to prevent overheating.

Steel or rubber lines carrying ATF between the transmission and cooler; cracks or leaks cause fluid loss and overheating.

Cleaning the cooler and lines of debris after an internal failure so contamination is not returned to a rebuilt unit.

The transmission's pump (gear or rotor type) driven by the converter that generates the line pressure all hydraulics depend on.

Air whipped into ATF from overfill or low level that compresses, causing erratic pressure, slipping, and overheating.

Too much ATF, which lets rotating parts churn the fluid into foam and raises temperatures.

Too little ATF, causing pump aeration, low pressure, slipping, delayed engagement, and overheating.

A threaded port on the case where a gauge connects to read line or circuit pressure during diagnosis.

Setting band apply clearance to specification (often a torque-and-back-off procedure) so the band holds without dragging.

Aligning the selector linkage or cable so the manual valve fully seats in each range and the indicator matches the gear.

A switch (often the range sensor) that allows cranking only in Park or Neutral and enables the reverse lamps.

Setting the throttle-valve cable so shift timing and firmness match load in cable-controlled transmissions.

Removing and cleaning or replacing the valve body or solenoids with the transmission still in the vehicle to fix hydraulic faults.

Swapping a faulty shift or pressure-control solenoid through the pan without removing the transmission, when accessible.

Replacing an input or output speed sensor that is causing erratic shifts or speedometer faults.

The rear seal around the output shaft/yoke; a common external leak point serviceable in the vehicle.

On a transaxle, the seal where a drive axle enters the case; a frequent in-vehicle leak repair.

The seal where the selector shaft enters the case; leaks here are repaired in the vehicle.

The seal at the vehicle-speed sensor or drive that can leak and is replaced in the vehicle.

The seal at the converter snout/pump; a leak here usually requires removing the transmission to access.

Adding UV dye to ATF and using a UV light to pinpoint the exact source of an external leak.

Loss of converter fluid into the pan after shutdown that causes a brief delayed engagement on the next start.

External leaks lose fluid to the ground; internal leaks pass fluid between circuits, causing slipping without visible loss.

Flashing TCM software or performing an adaptive relearn after service so shift adapts match the current hardware.

The TCM's running adjustment of clutch apply timing/pressure to compensate for wear, which may need resetting after repairs.

A rubber/hydraulic mount supporting the transmission; a worn mount causes clunks and driveline vibration.

A valve that warms ATF quickly by limiting cooler flow until temperature rises, then opens for cooling.

A push-to-connect cooler line fitting requiring a special tool and care to avoid leaks during service.

Adding the specified ATF type and quantity, then verifying level at the correct temperature with the engine running.

An automated manual using two clutches (odd/even gears) for fast, smooth shifts under computer control.

A pin that locks into the output gear to hold the vehicle in Park; a worn pawl or linkage can let the vehicle roll.

Correct routing and connection (out/return) of cooler lines so flow direction matches the transmission requirement.

A plugged filter that starves the pump, causing low pressure, slipping, and a whining pump under load.

Air or vapor bubbles forming at the pump from a restricted pickup or low fluid, causing noise and pressure loss.

Tuning apply pressure and solenoid timing so shifts are firm enough to protect clutches yet smooth for the driver.

Using an incorrect ATF (friction modifier mismatch) causing shudder, harsh or slipping shifts, and accelerated wear.

A stuck cooler-bypass valve causing overheating (stuck closed) or slow warm-up and poor economy (stuck open).

Incorrect driveline or mount alignment after R&R causing vibration mistaken for a transmission fault.

Foam from air (level/leak) versus milky fluid from coolant; the cause and fix differ, so identify which is present.

The low-pressure oil path that cools and lubricates the geartrain after pressure-regulator bleed-off; a blockage causes bearing failure.

An inline filter on the cooler return line that protects a rebuilt unit from debris left in the cooler system.

A scan-tool routine that resets and relearns shift adapts after a valve-body or transmission replacement.

Judging the type of debris (friction material, bronze, steel) in the pan to identify which component failed.

Measuring ATF flow at the cooler return to confirm the pump, cooler, and lines are not restricted.

The PRNDL display; a mismatch with the actual gear points to range-sensor or linkage misadjustment.

Setting the exact ATF level at the specified temperature after a road test, since level changes as the unit warms and fills.

A specialized jack with a cradle and safety chains used to lower, support, and raise the heavy transmission during R&R.

A bench fixture that clamps the case so the unit can be rotated and disassembled safely on the bench.

Sliding the torque converter straight off the input shaft after R&R so it does not fall and to inspect/replace it.

The thin steel plate bolting the converter to the crankshaft; inspected for cracks and worn ring-gear teeth during R&R.

Tightening the converter-to-flexplate bolts evenly to specification to prevent vibration and bolt failure.

The shaft driven by the converter turbine that delivers power into the gear train; inspected for worn splines and twist.

The shaft delivering power out of the transmission; checked for wear, runout, and damaged splines.

The controlled axial free movement of the geartrain, set with selective washers and measured with a dial indicator.

A tool that measures axial geartrain movement so the correct selective thrust washer can be installed.

A thrust washer or snap ring chosen by thickness to bring end play within specification during reassembly.

A set of precise blades used to measure clutch-pack clearance, band clearance, and other small gaps.

The measured gap in an apply clutch pack, set with selective plates/pressure plates so the clutch applies and releases correctly.

Applying shop air to a clutch circuit during reassembly to confirm the piston strokes and seals hold.

A plate lined with friction material that grips steel plates when the clutch applies; inspected for burning, glazing, and wear.

A bare steel plate alternating with friction plates; checked for heat discoloration, warpage, and scoring.

The thick plate that backs a clutch pack; its thickness can be selective to set clutch clearance.

The hydraulic piston and its lip/O-ring seals that apply a clutch; replaced during overhaul to restore apply pressure.

A plain bearing supporting a rotating shaft or drum; inspected for wear, scoring, and excess clearance during overhaul.

A bearing or washer that controls axial loads between rotating members; wear here increases end play and noise.

A flat caged needle bearing used between geartrain members to handle thrust loads with low friction.

Metal or Teflon rings on shafts and drums that seal rotating hydraulic circuits; inspected and replaced on overhaul.

Measuring pump gear/rotor clearances and checking the pump body for wear that would lower line pressure.

Using a feeler gauge to check gear-tip, side, and body clearances against spec to confirm pump condition.

Cleaning the valve body and checking valves for free movement, scoring, and a warped mating surface that causes cross-leaks.

The plate with calibrated orifices between valve-body halves; checked for wear, wrong orifices, and proper gasket alignment.

Examining the aluminum case for cracks, stripped threads, worn bores, and damaged sealing surfaces before reassembly.

The controlled load set on tapered bearings (in some transaxles/final drives) to remove play without overloading.

The play between final-drive/differential gears, measured and adjusted with shims in transaxle service.

The final-drive gear unit inside a transaxle that splits power to the drive axles and allows wheel speed difference.

The reduction gearset in a transaxle that transmits geartrain output to the differential.

Checking clutch drums for cracks, worn band surfaces, scored bushing bores, and damaged sealing-ring grooves.

A tool for removing and installing the snap rings that retain clutch packs, servos, and pump components.

A sleeve and driver set used to install lip seals and rings without cutting or rolling them.

Petroleum jelly or ATF-based lube used to hold thrust washers in place and pre-lube seals during reassembly.

The manufacturer-specified tightening value for case bolts, pump bolts, and the converter, applied in the correct sequence.

Cleaning all parts in solvent and drying with compressed air before inspection so debris and contamination are removed.

Adding ATF and rotating/cycling the unit after install to prime the pump and purge air before the first drive.

Verifying the converter is fully seated on the pump and stator splines before bolting to the flexplate to avoid pump damage.

Using case dowels to align the transmission to the engine block during installation so the bellhousing seats squarely.

A final verification drive checking shift quality, lock-up, and the absence of leaks and noise after reinstallation.

Pressure leaking between circuits past a warped valve-body face or worn separator plate, causing slip or wrong-gear apply.

The service chart relating measured end play to the thrust-washer thickness needed to bring it into spec.

Controlled break-in cycles after overhaul that seat new friction material for proper holding and shift feel.

A flexible seal with a sealing lip used on pistons and shafts; installed with the lip facing apply pressure.

A round-section rubber seal used in grooves to seal static or slow-moving hydraulic joints in the transmission.

A spring steel plate in a clutch pack that cushions initial apply for a smoother engagement.

The spring(s) that release a clutch piston when apply pressure drops, allowing the pack to disengage.

A rotating member transmitting power to a planetary element; inspected for cracks and worn splines on overhaul.

Worn pump bushing causing converter-hub wear, low pressure, and a front-pump leak; found during off-vehicle inspection.

Measuring drum surfaces for runout and warpage so bands and clutches seat correctly.

A shim selected to set tapered-bearing preload/endplay in transaxle final drives during reassembly.

Verifying correct fluid level, leak-free operation, full shift range, lock-up function, and no codes after any major repair.

Worn or distorted snap-ring grooves in drums or the case that prevent proper retention of clutch packs and must be inspected.

Checking converter pilot runout and balance after install to prevent vibration and flexplate cracking.

Verifying bellhousing-to-crank concentricity so the input shaft and converter are not loaded off-center.

Sealing rings on the input shaft that seal the apply circuits feeding the forward clutches; inspected on overhaul.

Wear in the regulator valve bore that lets line pressure fall off, causing general slipping under load.

The accumulator piston and seal that cushion apply; a stuck or leaking accumulator causes harsh or soft shifts.

The servo piston seal and bore that apply a band; leakage causes band slip and a specific gear fault.