Maharashtra HSC NSQF Automotive Service Technician (G3) key terms

A workplace organisation method with five steps: sort, set in order, shine, standardise and sustain. It keeps tools and work areas clean, arranged and consistently maintained so work is faster and safer.

Using markings, labels, colour codes and shadow boards so anyone can see at a glance where a tool belongs, what a warning means, or whether a work area is in its correct state.

A tool panel on which the outline of each tool is painted or cut out. A missing outline instantly shows a tool is absent, which supports accountability and prevents tools being left inside vehicles.

A scheduled check of a workshop area against defined cleanliness and order standards, scored and recorded so that deviations are corrected and improvement can be tracked over time.

A document supplied with a chemical product that lists its hazards, safe handling and storage requirements, first-aid measures and spill response. It must be accessible to workers who use or store the product.

Wearable protection such as safety goggles, gloves, hearing protection, safety footwear and breathing masks, selected according to the hazards of the task being performed.

Separating workshop waste streams - used oil, coolant, batteries, tyres, metal scrap and general refuse - into labelled containers so each can be recycled or disposed of lawfully without contaminating the others.

A measuring instrument with a fixed main scale and a sliding jaw scale, used to read outside, inside and depth dimensions. The least count is found by dividing the smallest main-scale division by the number of vernier divisions.

A precision instrument using a calibrated screw and thimble to measure small outside dimensions, commonly to 0.01 mm. The reading is the barrel scale plus the thimble division multiplied by the least count.

A set of thin steel blades of known thickness used to check small gaps such as valve clearance, spark plug gap or piston ring end gap by finding which blade fits the gap exactly.

A wrench that indicates or limits the tightening force applied to a fastener so a specified torque is reached. It must be calibrated and returned to its lowest setting after use to keep it accurate.

The defined order in which multiple fasteners, such as cylinder head bolts, are tightened, usually in a spiral from the centre outwards and in stages, to distribute clamping load evenly and prevent distortion.

An instrument with a spring-loaded plunger and a graduated dial that shows small linear displacements. It is used to measure runout, end play, backlash and shaft deflection while a component is rotated or moved.

A vehicle lifting device with two vertical posts and adjustable arms that raise a car by its chassis lifting points. The arms must be positioned correctly and the vehicle shaken gently before anyone works underneath.

A rigid, rated support placed under a vehicle chassis after it has been lifted, so the hydraulic jack does not remain the only thing holding the load. It is used whenever work is done under a raised vehicle.

The sequence of intake, compression, power and exhaust strokes completed in two crankshaft revolutions. Each stroke is defined by the piston direction and the state of the valves.

The ratio of the cylinder volume above the piston at bottom dead centre to the volume at top dead centre. It strongly influences power output, thermal efficiency and the fuel octane the engine requires.

The enclosed space between the cylinder head and the piston crown in which the air-fuel charge is burned. Its shape affects flame travel, turbulence and knock resistance.

The component that closes the top of the cylinders and carries the combustion chambers, valve seats, valve guides, ports and often the camshaft. It is sealed to the block by a head gasket.

The shaft that converts the reciprocating motion of the pistons and connecting rods into rotary motion. Its journals run in main bearings and its throws carry the big-end bearings.

The precise points, expressed in crankshaft degrees, at which the intake and exhaust valves open and close relative to piston position. Incorrect timing reduces volumetric efficiency and can cause piston-to-valve contact.

A toothed belt that drives the camshaft at exactly half crankshaft speed. If it fails, pistons and valves can collide, so it is replaced at the manufacturer's specified interval.

A friction device between the engine and gearbox that engages and disengages drive smoothly. It allows the vehicle to start from rest and lets gears be changed without interrupting engine power.

The number of teeth on the driven gear divided by the number on the driving gear. It determines the trade-off between output speed and torque, and the overall ratio includes the final drive.

A gear set that splits drive to the two wheels of an axle while allowing them to turn at different speeds in a corner. Its final-drive ratio also multiplies engine torque.

The small clearance between the meshing teeth of two gears, such as a crown wheel and pinion. Too little causes noise and overheating; too much causes shock loading and rapid wear.

Adjustment of camber, caster, toe and sometimes thrust angle so wheels sit correctly relative to the road and each other. Correct alignment prevents uneven tyre wear and steering pull.

The amount of charge a battery can deliver, expressed in ampere-hours, usually quoted at a standard discharge rate. It indicates how long the battery can supply a given current.

The remaining charge in a battery expressed as a percentage of full capacity. It is estimated from open-circuit voltage after a rest period or with a conductance tester.

The density of a liquid compared with water. In a lead-acid battery, electrolyte specific gravity falls as the battery discharges, so a hydrometer reading indicates state of charge.

A belt-driven generator that produces alternating current, rectified to direct current, to charge the battery and run vehicle loads while the engine runs. Its regulator holds charging voltage within a set range.

Measuring the potential difference across a cable, switch or connection while current flows. A high reading reveals excessive resistance, which is a common cause of slow cranking and dim lights.

A drawing that shows electrical components and the paths and colours of the conductors connecting them, with terminal numbers. It is the primary reference for tracing faults in a circuit.

A designated, ventilated area for storing and charging batteries, kept free of flames and sparks because charging releases explosive hydrogen. Acid-resistant flooring and spill neutralising material are provided.

The manufacturer's table of service operations to be performed at specified time or distance intervals, such as oil changes, filter replacement, fluid checks and inspections of brakes, tyres and suspension.

A checklist of checks and adjustments carried out on a new vehicle before it is handed to the customer, covering fluids, tyre pressures, electrical functions, road test and cosmetic condition.

The characteristic way a tyre has worn, such as centre wear from over-inflation, edge wear from under-inflation or feathering from misalignment. It is read as evidence of a fault.

Driving the vehicle under controlled conditions to confirm a repair, reproduce a customer complaint or assess behaviour such as braking, steering pull, noise and gear selection before and after work.

An alphanumeric code stored by an electronic control unit when it detects an out-of-range signal or failed self-test. The code identifies the circuit or system area, not necessarily the failed part.

A device that communicates with vehicle control units to read and clear fault codes, view live sensor data and perform actuator tests. It narrows diagnosis before any component is replaced.

The workshop document that records the vehicle, customer complaint, authorised work, parts used, labour time and technician signature. It authorises the work and supports billing and warranty claims.

A written statement of the expected parts and labour cost of a repair, given to the customer for approval before work begins. Additional work needs fresh authorisation.

Recommending additional genuinely needed services or parts to a customer, based on inspection evidence, without pressure or misrepresentation. It must respect the customer's right to refuse.