Slide 1

INTRODUCTION TO MANUAL TRANSMISSIONS & TRANSAXLES

RWD MANUAL TRANSMISSIONS

MANUAL TRANSMISSIONConstruction & Components

REVERSE IDLER GEAR

TRANSMISSION POWERFLOW

BEARINGS

SYNCHRONIZER ASSEMBLY

SYNCHRONIZER COMPONENTS

SYNCHRONIZED GEAR SHIFT1st Stage

SYNCHRONIZED GEAR SHIFT2nd Stage

SYNCHRONIZED GEAR SHIFT3rd Stage

SYNCHRONIZER HUB SLEEVE & SPLINES

TWO-CONE SYNCHRONIZER

THREE-CONE SYNCHRONIZER

GEAR SHIFT MECHANISM

GEAR SHIFT CONTROLShift Detent Mechanism

GEAR SHIFT CONTROLShift Interlock Mechanism

GEAR SHIFT CONTROLShift Interlock Operation

GEAR SHIFT CONTROLMis-Shift Prevention

GEAR SHIFT CONTROLReverse Mis-Shift Prevention

GEAR SHIFT CONTROLReverse Pre-Balk Mechanism

GEAR SHIFT CONTROLReverse One-Way Mechanism

GEAR SHIFT CONTROLReverse One-Way Mechanism Operation

TRANSMISSION LUBRICATIONCounter shaft gears rotate in lubricantCarries lubricant to output shaft gears and troughsTroughs or oiling funnels direct oil to shaft bearings and bushingsSome transmissions have Pumps which pump fluid down shaftsSpeed gears and shafts have drilled oil passagesDistributes lubricant to gear bearingsTransmission ventRelieve internal pressure (heat)If plugged, venting occurs past seal, resulting in leaks

GEAR OIL CLASSIFICATIONSGL-1Straight mineral oil/ Use additivesUsed in non-synchromesh transmissionsNot suitable for modern transmissionsGL-2A designation for worm gear drivesUsed in mostly industrial applicationsGL-3Contains mild EP additivesUsed in MTs with spiral bevel final drivesGL-4Used in MTs with hypoid final drives; contains half additives found in GL-5GL-5Contains enough EP additive to lubricate hypoid gears in drive axles

GEAR LUBRICANTSNewer Manual transmissions use following gear lubrication types:75W-90 GL4/GL580W-90 GL4/GL5Dextron IV Consult vehicle repair manual for specific lubrication information or shift quality will decrease!

CASE SEALANTSTransmission Cases Use Formed-In-Place Gaskets (FIPG):Room Temperature Vulcanizing (RTV)Made from siliconeSets to rubber-like material fast when exposed to airAnaerobic sealantsSimilar in function to RTVUsed to seal gaskets or to form gasketsCures in absence of air

MANUAL TRANSAXLES

MANUAL TRANSAXLE CONSTRUCTION

OPEN DIFFERENTIAL

VISCOUS COUPLING LIMITED SLIP DIFFERENTIAL

5 SPEED TRANSAXLES

6 SPEED TRANSAXLE

REVERSE IDLER GEAR

TRANSAXLE BEARINGS

KEY-LESS TYPE SYCHNRONIZERComponents

KEY-LESS TYPE SYCHNRONIZER1st Stage Synchronization

KEY-LESS TYPE SYCHNRONIZER2nd Stage Synchronization

KEY-LESS TYPE SYCHNRONIZER3rd Stage Synchronization

TRANSAXLE POWERFLOW

GEAR SHIFT CONTROLS

SHIFT & SELECT ASSEMBLY

GEAR SHIFT CONTROLSShift Detents

GEAR SHIFT CONTROLSDouble Meshing Prevention

GEAR SHIFT CONTROLSMis-Shift Prevention

GEAR SHIFT CONTROLSReverse Shift Detent Mechanism

GEAR SHIFT CONTROLSC & E Reverse One-Way Mechanism

TECHNICIAN HANDBOOK PAGE 4-25

GEAR SHIFT CONTROLSC & E Reverse One-Way Mech. Operation

TECHNICIAN HANDBOOK PAGE 4-26

GEAR SHIFT CONTROLSReverse Mis-Shift Prevention Mech. Op.

TECHNICIAN HANDBOOK PAGE 4-30

GEAR SHIFT CONTROLSReverse Pre-Balk Mech. - C Series Op.

TECHNICIAN HANDBOOK PAGE 4-31

GEAR SHIFT CONTROLSReverse Synchromesh Mechanism

TECHNICIAN HANDBOOK PAGE 4-33

TRANSAXLE LUBRICATION

C SERIES LUBRICATIONInput & Output Shafts

PUMP LUBRICATION

E SERIES LUBRICATION PATHS

COMMON TRANSMISSION/ TRANSAXLE PROBLEMSOil leakageHard to shiftWill not shiftLocked in gearJumps out of gearGear clash/grinding during shiftNoisy in neutralNoisy in one gearNoisy in all gearsGear roll over noise

COMMON TESTSEngine Off Shift Test ProcedureDisengage clutch by depressing clutch pedalShift transmission/transaxle into gear & shift to neutralShift back to originally selected gearNote amount of effort requiredRepeat check on all remaining gearsNote any shift requiring increased effort

COMMON TESTSEngine Running Shift TestTo perform:Set parking brake & start engineIdle engine in neutralNote unusual noisesDisengage clutch & shift into first gear; note:Amount of effort required to complete shift & compare to engine-off testUnusual noisesRelease parking brakeEngage clutch to move vehicle slightlyCheck for unusual noises or movementRepeat process for each gear position

COMMON TESTSRoad Test ProceduresWarm up transmission before road testCheck transmission oil levelWith vehicle stationary in neutral, and engine idling:Disengage clutchEngage clutch & listen for noiseRepeat steps above & wait three secondsShift into reverse, first gear, & back to reverseWait twenty seconds & repeatNote differences in noise, shifting ability, pedal movement, and position of clutch engagement

COMMON TESTSRoad Test ProceduresShift into reverse, release pedal, & back up, increasing engine speed to 2,500 rpmNote any noisesDrive vehicle on road:Start in first gear, accelerate, & upshift at 4,000 rpm through all gears note shift quality & noises (Observe speed limits & safety)Decelerate using engine braking downshift in each gear & note noisesOn highway, drive in fourth gear at 60 mph, accelerate & shift into fifth gear note any problems

SYMPTOM DIAGNOSTIC CHART

DIAGNOSTIC FLOWCHARTHard to Shift/Will Not Shift

DIAGNOSTIC FLOWCHARTGear Slip-Out

GEAR THRUST CLEARANCE CHECKS

SHIFT FORK COMPONENT WEAR

WORN GEAR SPLINES

Overhaul Tips & InspectionsAlways double check sleeve orientation on assembly!Check for free rotation many times through build and after pressing on gears/bearings!

Snap rings and Snap ring groovesCheck for wearSnap rings have a round and flat sideFlat side goes with thrustGear TeethCheck for chips and wearChips in non contact area can be ground downAlways replace gears in sets or noise will occur

Overhaul Tips & InspectionsSynchronizer ringsReplace all of themCheck contact area and lap if neededCheck sleeves and speed gearsIf dog teeth are worn replaceMain and counter shaft bearingsReplace at time of overhaul0 axial play on roller ball bearingsPreload tapered roller bearingsCheck bearing retainers for wear

Overhaul Tips & InspectionsFinal drive bearingsReplace and set preloadUsually done with shimsCheck spider and side gears for excess back-lashCheck pinion pin for playCheck for free rotationBench shift several times

End manual transmissions