Basics Of Automobile

The gear shifting mechanism inside the gear box can

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Unformatted text preview: hicle moving. Hence a intermediate ratio is required. GEAR BOX GEAR CHANGE MECHANISM(EXTERNAL) - A desired gear ratio can be selected by the driver by selecting and shifting the gear lever GEAR SHIFTING 1 3 5 1 3 GEAR SELECTION 2 4 R 5 SPEED TRANSMISSION • BA10 • NISSAN • ISUZU 2 4 R 4 SPEED TRANSMISSION • KMT 90 • MS 90 GEAR BOX GEAR CHANGE MECHANISM(INTERNAL) - The desired gear ratio selected by the driver is transmitted through the gear lever, set of shift rails to the gears located inside the gear box. The gear shifting mechanism inside the gear box can be broadly classified as : SLIDING MESH - In which , the gears needs to be moved physically in to mesh with the corresponding gear. This requires that the vehicle is stationary when the gears are shifted, Hence sliding mesh is obsolete and is used only in First Gear or Reverse gear. CONSTANT MESH - In which, all the gears are in constant mesh and the required gear engagement is achieved by operating a synchroniser mechanism. Synchronisation mechanism can be classified as : Manual Synchronisation - As in Leyland trucks - Double de-clutching Automatic Synchronisation - Single stroke shifting GEAR BOX SYNCHRONISER MECHANISM - In order to avoid gears crashing, when shifting from one gear ratio to another, it is required to match the speeds of both the drive & the driven gears, before the shifting can happen. Synchroniser mechanism does the job of synchronising the speeds of the drive & driven gear so that shifting takes place smoothly. All forward gears (except First) need to have synchronisers Synchroniser mechanism are of different designs : Strut type - As in KMT 90 gear box/Isuzu Gear box Pin Type - As in BA10 gear box SAMPLE LEAFLET MARSHAL 2000 TRANSMISSION : 4 SPEED, 2nd, 3rd & 4th Synchromesh 1st GEAR - 3.986 : 1 2nd GEAR - 2.368 : 1 3rd GEAR - 1.473 : 1 4th GEAR - 1.000 : 1 REVERSE - 5.315 : 1 Driveline_gear.exe SYSTEMS IN AN AUTOMOBILE A. POWER TRAIN SYSTEM • POWER PLANT (POWER GENERATION - ENGINE) • ENGINE • FUEL SYSTEM • INTAKE SYSTEM • EXHAUST SYSTEM • COOLING SYSTEM • DRIVE LINE (POWER TRANSMISSION ) • CLUTCH • GEAR BOX/TRANSMISSION • TRANSFER CASE • DIFFERENTIAL • WHEELS/TYRES B. RUNNING SYSTEM • SUSPENSION • STEERING • BRAKING C. COMFORT SYSTEM • HVAC/AC/HEATER SYSTEM • SEATING/UPHOLSTRY/FACIA/INSTRUMENTS • AUDIO/VIDEO/GPS TRANSFER CASE TRANSFER CASES ARE FITTED ONLY IN 4WD VEHICLES TRANSFER CASE MODIFIES & RE-DIRECTS THE TORQUE OF THE ENGINE TO BOTH FRONT AND REAR AXLES, AS DESIRED. 4WD VEHICLES CAN BE CLASSIFIED AS : FULL TIME 4WD - Where all the 4 wheels are connected to the engine, permanently. Also known as All Wheel Drive(AWD) PART TIME 4WD - Where either 2WD mode or 4WD mode can be selected by the driver by shifting a gear lever (Manual shift)) or by turning a switch (Electric shift) ANATOMY OF AN AUTOMOBILE (FOUR WHEEL DRIVE) STEERING PROPELLOR SHAFT - FRONT TYRE BRAKE TYRE BRAKE DIFFERENTIAL 4WD ENGINE GEAR BOX DIFFERENTIAL CLUTCH BRAKE SUSPENSION TYRE PROPE...
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This document was uploaded on 03/30/2014.

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