INTRODUCTION TO MANUAL TRANSMISSIONS & TRANSAXLES

INTRODUCTION TO MANUAL TRANSMISSIONS & TRANSAXLES

DRIVETRAIN CONFIGURATIONS

MANUAL TRANSMISSIONS

TORQUE

DETERMINING GEAR RATIOS

GEAR TYPES

TORQUE MULTIPLICATION FORMULAFind ratio by dividing drive by drivenDrivenDrive

RPMRatioOverall ratio is the product of each ratio

Output torque is the product of torque and ratioOutput RPM is the quotient of RPM and Ratio Ratio X RatioTorque X Ratio

CLUTCH ASSEMBLY

FLYWHEELCan be a Stepped Flywheel

Dual-Mass FlywheelUsed to dampen torsional vibrationsCommon of Diesel enginesProne to excessive noise and axial play when worn

CLUTCH DISC

CLUTCH HUB & DAMPER POWER-FLOWMARCEL

Clutch DisksClutch facing coefficient of friction specific to powertrainHigh Performance disks have high COF and not good for streetNon cushioned disks should not be used in street aplications

CLUTCH COVER ASSEMBLYAKA PRESSURE PLATE

PRESSURE PLATESUse diaphragm or coil springs to Clamp clutch disk between flywheel and pressure plate.Some may have a means of increasing holding capacity at higher engine RPM

OTHER CLUTCH COVER ASSEMBLYS

Borg & Beck

Long Style

Pull Type

Center Force

PRESSURE PLATES

Self-Adjusting Pressure PlateCompensates for disk wearMust be ReSet when installedKeeps clutch pedal travel constant

DOUBLE DISK PRESSURE PLATE/CLUTCHPressure plate has second floating plateTwo clutch disks allow for more holding capacity

CONVENTIONAL RELEASE/ THROWOUT BEARINGPull type Pressure Plates pull release bearing out.

RELEASE /THROWOUT BEARINGSTOB presses on fingers of Pressure Plate to disengage clutchShould be replaced every time clutch is replaced

SELF-CENTERING RELEASE BEARINGUsed on transaxles that dont use a Pilot BearingReduces noise

SELF-CENTERING RELEASE BEARING

HYDRAULIC CLUTCH SYSTEM

MASTER CYLINDER*Some clutch reservoirs can be part of the brake master cylinder reservoir*

SELF-ADJUSTING RELEASE/SLAVE CYLINDER

INTEGRAL RELEASE/SLAVE CYLINDERSome vehicle have both Slave Cylinder & Throw Out Bearing as an assembly.Replace as a set.

SELF-ADJUSTING RELEASE/SLAVE CYLINDER BLEEDINGSystems use DOT 3 Brake FluidGravity bleedingCrack bleed screw and let fluid run out.2 person methodClutch pedal is pumped upBleeder screw opened when pedal is held to floor.Stop when no more air comes out.Pressure BleedingUse pressure pot attached to master to force air out.RFI (reverse fluid injection)Best method for awkward master placementsPushes fluid up to master from slave.Hill methodDont ask

RELEASE/SLAVE CYLINDER BLEEDERSPressure PotRFI Gun

MECHANICAL CLUTCH SYSTEM

SELF ADJUSTING MECHANICAL CLUTCH SYSTEMSome mechanical clutches have an automatic adjusterCompensates for cable stretchNot good for HD Pressure Plates

CLUTCH PEDAL ADJUSTMENTClutch Reserve

CLUTCH PEDAL ADJUSTMENTClutch Release Point Inspection

CLUTCH PEDAL ADJUSTMENTClutch Start System CheckVehicle should NOT start unless clutch is depressed to floor.Misadjusted clutch switch can cause starter failureAlso used as input to Cruse Control

CLUTCH COMPONENT INSPECTIONCheck crankshaft end play firstPress in while measuring runoutShould not exceed .005Check for hot spots and bluingLook for cracksMeasuring Flywheel Axial Runout

CLUTCH COMPONENT INSPECTIONClutch Cover Assembly

CLUTCH COMPONENT INSPECTIONClutch Disc

CLUTCH COMPONENT INSPECTIONRelease Bearing

CLUTCH SERVICE & DIAGNOSISClutch Slippage Stationary CheckEngine at normal operating temperatureBlock wheelsApply parking brakeShift into highest gearRelease clutch pedal in smooth, normal motionIf clutch engaging correctly, engine stallsDelay in engine stalling indicates slipping clutch

CLUTCH SERVICE & DIAGNOSISClutch Slippage Road TestEngine at normal operating temperatureAccelerate to 15 - 20 mph & shift to highest gearMake full throttle accelerationEngine speed should increase steadily & smoothlyIf engine rpm increases without increase in vehicle speed, clutch is slipping

CLUTCH SERVICE & DIAGNOSISClutch ChatterSevere vibration while engaging clutchResults from clutch grabbing & slipping repeatedlyMares pressure plate & flywheel surfacesCausesClutch assembly relatedInfluences outside clutch assembly

CLUTCH SERVICE & DIAGNOSISClutch Drag

Does not fully disengage from engineCauses hard shift & gear clashClutch Spin Down TestChecks for complete clutch disengagementEngine & transmission at operating temperatureTransmission in neutral & engine idlingPush clutch pedal downWait nine secondsShift transmission into reverseGear clash or grinding indicates clutch not completely releasedCauses of failed spin down testClutch release controlsBinding or seized pilot bearingOil on clutch disc (leaking oil seal)Dragging clutch disc splinesFaulty clutch disc or clutch coverAir in hydraulic circuit

CLUTCH SERVICE & DIAGNOSISCommon Bearing Noise ProblemsTransmission bearing noise stops as pedal is depressedInput shaft, counter shaft & gears stopFaulty release bearing noise starts as pedal depressed beyond free playFaulty pilot bearing noise after clutch pedal fully depressed & transmission placed in gearInput shaft stops while flywheel & crankshaft rotate

CLUTCH SERVICE & DIAGNOSISClutch Assembly Noise CheckEngine & transmission at operating temperatureSet parking brake, engine at idle & transmission in neutralSlowly depress clutch pedal & listen for unusual noiseAs clutch releases & transmission gears spin downStill noisy - shift into gear to stop input shaft Noise goes away - Input shaft bearing, Counter bearing, Speed gear bearingRelease clutch pedal until gears are turningPilot bearing is stopped and release bearing is still turning

CLUTCH ASSEMBLY SERVICERemoving Pilot Bearing

CLUTCH ASSEMBLY SERVICEClutch ReassemblyApply thread sealer to boltsCheck flywheel bolt torqueInstall new pilot bearing into crankshaft recessUse appropriate driver tool against outer raceEnsure new clutch disc slides freely over input shaft splines

CLUTCH ASSEMBLY SERVICEInstall Clutch DiscLook for mark on Disk Flywheel Side

CLUTCH ASSEMBLY SERVICEInstall Clutch Cover Assembly

CLUTCH ASSEMBLY SERVICEGreasing ComponentsCheck bearing retainer for wear and replace if necessary or TOB can hang up or bind.Check release fork pivot points for wear. Replace if worn.

CLUTCH ASSEMBLY SERVICETransmission Installation

End Clutchesany Questions