The document discusses the transmission system in vehicles. The transmission system transmits power from the engine to the wheels. It allows the engine to operate at high speeds while wheels turn slower. The transmission provides different gear ratios to allow for variable torque output. It includes features like neutral position and reversing. The transmission must meet requirements like varying tractive effort at different speeds and engaging/disengaging power. Common types discussed are manual, automatic, and overdrive transmissions. Specific transmission components like sliding mesh gears, constant mesh gears, synchromesh, selectors and torque converters are described. Troubleshooting of transmission systems is also mentioned.

1. Vehicle Systems
Topic- Transmission System
BY
Prof. Pratik Raut
Class-B.E.(Mechanical) Div.: A & B SEM-VII
CO-1 : Understand the working of different Vehicle Systems and Subsystems

2. Transmission System :
Transmission system in a car helps to transmit
mechanical power from the car engine to give
kinetic energy to the wheels.

3. Layout :

4. Functions :
• To provide the high torque at the time of starting, hill climbing,
accelerating and pulling a load since high tractive effort is
needed
• It permits engine crankshaft to revolve at high speed, while the
wheels turn at slower speeds
• Variable torque by set of gears
• Vehicle speed can be changed keeping engine speed same with
certain limit
• The transmission also provides a neutral position so that the
engine and the road wheels are disconnected even with the
clutch in the engaged position
• A means to back the car by reversing the direction of rotation
of the drive is also provided by the transmission

5. Necessity / Requirements :
• Variation of resistance to the vehicle motion at various
speeds
• Variation of tractive effort of the vehicle available at various
speeds
• To engaged or disengaged the power from engine to
transmission system
• To transmit the torque
• To distribute the final torque equally between the driving
wheels.
• To Provide the torque needed to move the vehicle under a
variety of road and load conditions.

6. Types of Gear Boxes :
• Manual
• Sliding Mesh Gear box
• Constant Mesh Gear box
• Synchromesh Gear box
• Automatic
• Over drive (semi-automatic)
• Fluid drive or Fluid coupling
• Fully automatic
• Epicyclic gear box
• Free Wheeling unit
• Torque Convertor

7. 1. Sliding mesh gear box :

8. 2. Constant Mesh Gear Box :

9. Double-Declutching :

10. Advantages of Constant
Mesh Gearbox :

11. Synchromesh
Gearbox :
• This type of gearbox is similar to
the constant mesh type gearbox.
• Instead of using dog clutches here
synchronizers are used.
• The modern cars use helical gears
and synchromesh devices in
gearboxes, that synchronize the
rotation of gears that are about to
be meshed

12. Gear selector Mechanisms :
• 1. Mechanism with gear lever on top of
Transmission Case
• 2. Mechanism with gear lever on steering
Column

13. 1. Mechanism with gear lever on top
of Transmission Case

14. 2. Mechanism with gear lever on
steering Column

15. Gear Box Trouble Shooting

16. Gear Box Trouble Shooting

17. Gear Box Trouble Shooting

18. Gear Box Trouble Shooting

19. Gear Box Trouble Shooting

20. Gear Box Trouble Shooting

21. Manual Transmission Link :
• https://youtu.be/wCu9W9xNwtI

22. Overdrive :
• Is a device which is used to
step up the gear ratio in
the vehicle.
• It is mounted in between
transmission and propeller
shaft.
• A transmission is in
overdrive when the
transmission output shaft
is turning faster than
the transmission input
shaft, or clutch gear.
• Overdrive is generally fixed
on top gear only.
Link:
https://www.youtube.com/watch?v=R
uVINSha4VM

23. Hydrodynamic Torque
Converter:
• A Torque Convertor
is a type of fluid
coupling capable of
producing torque.
• Replacement of
Clutch for Automatic
Transmission
Vehicle.
Link : https://youtu.be/bRcDvCj_JPs

24. Epicyclic Gear Box (Not in Syllabus)
Link : https://youtu.be/ARd-Om2VyiE
https://www.youtube.com/watch?v=u_y1S8C0Hmc

25. Comparison between
AMT vs CVT vs DCT vs AT :
(Not in Syllabus)
• Link : https://youtu.be/q0aOXVndCx4