Mechanic Motor Vehicle (MMV) Trade Theory

The Mechanic Motor Vehicle (MMV) trade is a specialized vocational course designed to train students in the maintenance, repair, and overhauling of various types of motor vehicles. This syllabus outlines the theoretical knowledge required to understand the complex systems operating within modern automobiles, including two-wheelers, three-wheelers, and heavy-duty vehicles.

1. Introduction to the Trade

The foundational module provides an overview of the automobile industry and the role of a motor vehicle mechanic. It focuses on the history of automobiles, safety standards, and the identification of various vehicle tools and equipment.

Key Topics:

• Introduction to the automobile industry and job opportunities.
• Identification of various types of vehicles: light motor vehicles (LMV), heavy motor vehicles (HMV), and two-wheelers.
• Study of workshop safety, personal safety, and first aid.
• Introduction to measuring instruments (Vernier calipers, micrometers, dial gauges).
• Identification, care, and maintenance of hand tools, precision tools, and workshop equipment.

2. Basic Electricity and Electronics

Modern vehicles rely heavily on electrical and electronic systems. This module covers the fundamental principles of electricity, magnetism, and semi-conductor devices used in automotive applications.

Key Topics:

• Concepts of voltage, current, resistance, and Ohms Law.
• Series and parallel circuits.
• Types of batteries:Lead-acid batteries, construction, working principles, and maintenance.
• Demonstration of battery charging and testing methods using hydrometers and battery testers.
• Introduction to semiconductors: diodes, transistors, and ICs.
• Use of multi-meters for testing electrical components.

3. Vehicle Lubrication and Cooling Systems

Theory regarding thermal management and friction reduction is critical for engine longevity. This section explains the properties of lubricants and the function of cooling systems.

Key Topics:

• Functions and properties of lubricating oil.
• Viscosity and viscosity index (SAE grading).
• Types of lubrication systems: splash, pressure feed, and mist lubrication.
• Construction and working of the oil pump, oil filter, and oil cooler.
• Necessity of cooling systems in engines (Air-cooling vs. Water-cooling).
• Components of water cooling: radiator, water pump, thermostat, and cooling fan.
• Coolants: properties, types, and maintenance.

4. Internal Combustion Engines

This is the core of the syllabus, dealing with the power-generating unit. Students learn the theoretical construction and operation of both petrol and diesel engines.

Key Topics:

• Definition and classification of IC engines (SI vs CI).
• Construction details: cylinder block, cylinder head, piston, connecting rod, crankshaft, and camshaft.
• Working principles of 2-stroke and 4-stroke engines.
• Valve timing diagrams and port timing diagrams.
• Fuel supply systems for Petrol engines: carburetor vs. MPFI (Multi-Point Fuel Injection).
• Fuel supply systems for Diesel engines: fuel pump, injectors, and common rail direct injection (CRDI).
• Engine tuning and performance parameters.

5. Transmission Systems

This section covers the mechanism that transmits power from the engine to the wheels. It includes the study of the clutch, gearbox, propeller shaft, and differential.

Key Topics:

• Necessity of the clutch and its construction (single plate, multi-plate).
• Principles of fluid coupling and torque converters (used in automatic transmissions).
• Functions of the gearbox: types (constant mesh, synchromesh).
• Layout and function of the propeller shaft, universal joint, and slip joint.
• Working principle of the final drive, differential, and rear axle.
• Introduction to transaxles and front-wheel drive mechanisms.
• Theory of 4WD and AWD systems.

6. Chassis, Steering, and Brakes

Understanding the frame, suspension, steering mechanism, and braking systems is essential for vehicle control and safety.

Key Topics:

• Types of chassis: conventional, semi-forward, and integral.
• Suspension systems: leaf springs, coil springs, shock absorbers, and independent suspension systems.
• Wheel alignment and balancing theory (Camber, Caster, King Pin Inclination, Toe-in/Toe-out).
• Steering systems: rack and pinion, recirculating ball, and power steering.
• Braking systems: mechanical, hydraulic, and air brakes.
• Drum brakes and disc brakes: construction and working principles.
• Anti-lock Braking System (ABS) and Electronic Stability Control (ESC).

7. Auxiliary Systems and Body Maintenance

This module covers additional comfort and safety features found in modern vehicles, as well as basic bodywork theory.

Key Topics:

• Lighting systems: headlights, tail lights, indicators, and HID/LED technology.
• Horn, wiper, and washer mechanisms.
• Air conditioning system: refrigeration cycle, components (compressor, condenser, evaporator), and refrigerants.
• Instrument panel cluster: speedometer, odometer, fuel gauge, and warning lights.
• Basics of body construction, panel beating, and dent removal.
• Painting fundamentals: surface preparation, primers, and spray painting techniques.

8. Maintenance, Troubleshooting, and Legislation

The final module focuses on the systematic approach to maintaining vehicles and adhering to environmental and legal standards.

Key Topics:

• Preventive maintenance and Periodic Maintenance Systems (PMS).
• Service schedules for different vehicle manufacturers.
• Troubleshooting charts for engine starting issues, overheating, and abnormal noises.
• Diagnosis of electrical faults using wiring diagrams.
• Pollution control: vehicular emissions (CO, HC, NOx) and catalytic converters.
• Vehicle insurance and registration procedures.
• Motor Vehicle Acts and rules regarding road safety and pollution control.