In this article we discuss the automobile transmission system in detail.

Automobile Transmission System

1. What is an automobile transmission system?

The transmission system in an automobile is a mechanical system that transmits power from the engine to the wheels. Its primary function is to allow the vehicle to move at different speeds and torque levels efficiently.

Without a transmission, the engine would either stall at low speed or over-rev at high speed.

2. Purpose of Transmission:

Convert engine output (high speed, low torque) to wheel requirements (varied speed, higher torque).
Allow the vehicle to move forward, reverse, and stop smoothly.
Enable fuel-efficient operation by optimizing engine speed.

3. Main Components of a Transmission System

1. Gearbox

Contains gears of different sizes to provide various speed ratios.
Types:
1. Manual Transmission (MT): Driver manually shifts gears using clutch and gear lever.
2. Automatic Transmission (AT): Uses torque converter and planetary gear sets; shifts automatically.
3. Semi-Automatic / Dual-Clutch Transmission (DCT): Combines manual and automatic features; computer-controlled clutch.

2. Clutch

Connects/disconnects engine to gearbox in manual transmissions.
Types:
- Single plate clutch
- Multi-plate clutch
- Wet or dry clutch

3. Driveshaft / Propeller Shaft

Transmits torque from the gearbox to the differential (rear wheels in RWD).

4. Differential

Splits torque between left and right wheels.
Allows wheels to rotate at different speeds during turns.

5. Axles

Transfer torque from differential to wheels.

4. How Transmission Works

Manual Transmission (MT)

Engine produces power → clutch → gearbox input shaft.
Driver selects gear → gears mesh → output shaft rotates.
Output shaft → driveshaft → differential → wheels.
Gear ratios determine speed vs torque:
- Lower gears → higher torque, lower speed (starting, climbing).
- Higher gears → lower torque, higher speed (cruising).

Automatic Transmission (AT)

Torque converter connects engine to planetary gear sets.
Hydraulic or electronic controls shift gears automatically.
Provides smooth acceleration without manual clutch operation.
Uses planetary gear sets to provide multiple gear ratios in compact space.

5. Types of Transmission Systems

Type	Features	Application
Manual Transmission (MT)	Driver-operated clutch & gear lever; simple & reliable	Passenger cars, light commercial vehicles
Automatic Transmission (AT)	Torque converter, hydraulic control; no clutch pedal	Modern cars, SUVs
Continuously Variable Transmission (CVT)	Uses belt & pulley system; infinite ratios	Scooters, compact cars
Semi-Automatic / DCT	Automated clutch control; faster shifts	Sports cars, high-performance vehicles
Electric Vehicle Transmission	Often single-speed reduction; no clutch	Electric vehicles

6. Key Functions of Transmission

Torque Conversion – Converts high-speed engine output into usable torque for wheels.
Speed Variation – Allows vehicle to run at different speeds.
Direction Control – Enables forward and reverse motion.
Power Transmission Control – Smooth engagement & disengagement through clutch or torque converter.

7. Common Problems in Transmission Systems

Manual Transmission: Gear grinding, clutch slipping, difficult shifting.
Automatic Transmission: Fluid leaks, delayed shifts, overheating of torque converter.
CVT: Belt slipping, overheating, loss of acceleration.

8. Maintenance Tips

Check transmission fluid regularly (AT, CVT).
Clutch adjustments and replacements for MT.
Avoid riding the clutch in manual cars.
Regular servicing of torque converters and gear mechanisms in automatic cars.

Summary:

The transmission system is the link between engine and wheels that converts engine power into useful torque, provides multiple speed ratios, and allows smooth operation of the vehicle.