ASE A3 flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Clutch Pedal Free Play

The distance the pedal moves before the release bearing contacts the pressure plate fingers; typically about 1/2 to 1 inch. Too little free play causes slippage and bearing wear.

Clutch Chatter Causes

Chatter during engagement comes from oil-contaminated facings, a warped flywheel or pressure plate, a worn pilot bushing, or loose engine and transmission mounts.

Pilot Bearing Noise

A squeal or growl heard with the clutch pedal depressed and a gear selected, disappearing when the clutch engages; the stationary input shaft is turning inside the bearing.

Throwout Bearing Noise

A growl or rumble that begins as soon as the clutch pedal is depressed and changes pitch with pedal pressure, because the bearing is loaded against the pressure plate fingers.

Clutch Slip Diagnosis

Engine rpm rises without matching vehicle speed under load, most noticeable in high gear; check for oil-fouled facings, a weak diaphragm spring, or insufficient pedal free play.

Hydraulic Clutch Bleeding

Air trapped in the master or slave cylinder prevents full clutch release. Bleed at the slave cylinder bleeder screw until clear, bubble-free fluid flows.

Clutch Disc Rivet Depth

Measure the remaining friction facing thickness above the rivet heads with a gauge; replace the disc when the facing is within about 0.015 in (0.4 mm) of the rivets.

Synchronizer Blocking Ring

The brass ring that friction-matches gear speeds before engagement. A worn ring or too little ring-to-gear gap causes gear clash during shifts.

Input Shaft Bearing Noise

Growling present in all gears except direct drive, where the countershaft is no longer driven, confirms the input shaft or countershaft bearing is worn.

Manual Transaxle Final Drive

In a transaxle the differential sits inside the transmission case. The output shaft drives the final drive ring gear, which turns the differential case and axle shafts.

Gear Ratio Torque Multiplication

Output torque equals input torque multiplied by the gear ratio; at the wheels the torque is multiplied again by the final drive ratio.

MPH From RPM Formula

MPH = (RPM x tire diameter in inches) / (gear ratio x final drive ratio x 336). Used to check speedometer accuracy and gear ratio selection.

Shift Interlock Function

Detent balls and interlock pins prevent two gears engaging at once and hold each shift fork in place; wear causes popping out of gear.

Pops Out Of Gear

Caused by worn synchronizer sleeves or engagement teeth, bent shift forks, weak detent springs, worn bearings allowing shaft end play, or loose shift linkage.

U-Joint Cancellation Angle

The front and rear universal joint operating angles must be equal and opposite, usually within about 1 degree, so their speed fluctuations cancel and vibration is avoided.

Drive Shaft Phasing

On a two-joint shaft the slip yoke and tube yokes must be aligned in the same plane; incorrect phasing produces a strong cyclic vibration.

Cardan Joint Speed Variation

A single universal joint accelerates and decelerates the driven shaft twice per revolution; constant velocity joints are designed to eliminate this fluctuation.

Outboard CV Joint Clicking

A rhythmic click or pop while turning under power indicates a worn Rzeppa ball joint, usually after a torn boot has expelled grease and admitted dirt.

Inboard CV Joint Vibration

Shudder or vibration during straight-line acceleration points to a worn plunge joint (tripod or double offset) or a binding inboard joint.

Center Support Bearing

The rubber-cushioned carrier that supports a two-piece drive shaft; a cracked insulator or rough bearing causes clunking and vibration at certain speeds.

Final Drive Ratio

Ring gear tooth count divided by pinion tooth count. For example, 41 ring teeth and 11 pinion teeth produce a 3.73:1 ratio.

Open Differential Torque Split

An open differential delivers equal torque to both wheels, so total usable traction is limited to twice the traction available at the wheel with less grip.

Limited Slip Chatter

A clutch-type limited slip that chatters or shudders in tight turns usually needs the specified friction modifier added to the gear lubricant.

Pinion Bearing Preload

Set with a crush sleeve or shims and verified by measuring rotating torque at the pinion; excessive preload destroys bearings, while too little causes whine.

Ring Gear Backlash

Measured with a dial indicator perpendicular to a tooth at the ring gear. Too little backlash causes whine and scoring; too much causes impact noise.

Gear Contact Pattern

Checked by coating ring gear teeth with marking compound and rotating the assembly under load; the pattern reveals pinion depth and backlash errors.

Full Floating Axle

An axle design in which the shaft transmits torque only; the wheel hub rides on bearings on the axle housing, so vehicle weight is not carried by the shaft.

C-Clip Axle Retention

The axle shaft is held in the differential by a C-clip; in-and-out shaft movement, seal leaks, or a grooved shaft usually indicate a worn C-clip or side gear.

Part-Time 4WD Windup

Part-time systems have no center differential, so on dry pavement the front and rear drivetrains bind. Use 4WD only on loose or slippery surfaces.

Center Axle Disconnect

A vacuum or electric collar on the front axle tube that couples one half-shaft; a failed actuator, vacuum line, or collar leaves 4WD inoperative.

Tire Size Matching 4WD

All four tires must match in size and wear within a small tolerance; mismatched rolling diameters make the transfer case fight and cause windup and vibration.

Axle Ratio Front And Rear

Front and rear differential ratios must match exactly; a mismatch causes driveline binding as soon as four-wheel drive is engaged.