Thursday, 31 October 2024, 11:54 PM
Site: IMI eLearning
Course: IMI eLearning (IMI eLearning)
Glossary: Automotive Glossary
S
S Classification (SAE)Engine oil suitable for gasoline engines. The second letter in the classification denotes the quality and minimum conditions that the oil must meet. |
S.W.LSafe Weight Limit." |
SAESociety of automotive engineers. SAE International is the premier membership society dedicated to advancing mobility engineering worldwide. SAE is a global technology information and standards organisation. |
SaggingExcessive flow on a vertical surface resulting in drips and other imperfections on the painted surface. Can Occur not only when the paint is wet, but also during baking in certain types of paints. |
SandTo smooth a surface with an abrasive paper or cloth. |
Sandblasting (grit-blasting)A method of cleaning metal, usually steel, by applying an abrasive with pressurised air. This is a very efficient method of removing paint and corrosion prior to repainting. |
SanderA power tool used with abrasives to roughen up or smooth surfaces quickly. |
Sanding Block (Rubbing block)A hard, flexible block to provide a smooth, consistent backing for abrasive papers used in hand sanding. |
Sandscratch SwellingExaggerated distortion of sanding marks in the underlying surface, usually caused by solvents in the topcoat attacking the substrate. |
SandscratchesTracking in the topcoat of sanding marks in the substrate. Usually caused by either flatting with abrasives that are too coarse, or failure to adequately fill sanding scratches with primer fillers/surfacers |
SatelliteThis can refer to any celestial body orbiting around a planet or star but usually means man-made equipment that orbits the Earth. |
SatinA surface finish that is approximately half-way between gloss and matt |
SaturationA term referring to a colour's purity or richness. The more chroma in a colour, the more saturated that colour is. |
SAWSpark advance word output signal. |
SCSupercharged |
Scan ToolDiagnostic tool that connects to an electronic control module on a vehicle to read fault codes and other data. |
ScannerDiagnostic tool that connects to an electronic control module on a vehicle to read fault codes and other data. Some scanners can also connect to controller area networks (CAN). |
ScanningTo skim/scan text in order to get a general idea about it. |
Scavenge PumpThe oil pump in the oil pan of a dry sump (oil pan) engine that returns the lubricating oil to a separate reservoir. |
ScavengingThe process in the combustion chamber that clears the residual exhaust gases by the incoming air charge. The inlet and exhaust valves are both open for a very brief spell as the engine moves across top dead centre at the end of the exhaust stroke. |
Schrader ValveA spring loaded valve for retaining the pressure in a tyre and to allow for tyre inflation. Fitted into the rim of a wheel either as a separate valve for tubeless tyres or as part of the tube for tubed tyres. |
SciaticaNeuralgia of the hip and thigh. |
ScopeShort for oscilloscope - Test equipment with a screen that can display electrical signals. |
Scraper RingPiston ring that controls amount of oil on cylinder wall. |
Screw ThreadA method of increasing force. |
Scrub RadiusEffect on the tyre of steering turn. |
ScuffingA rubbing wear due to lack of lubrication or incorrect alignment. Examples are cylinder scoring and tyre tread wear on one side of a tyre only. |
SealOil, water or gas tight join. |
Seal LandThe area on shafts that an oil seal lip seals against. |
SealantA liquid material that is used with or, in place of, a gasket to give a gas or liquid seal. Sealants can be either fully setting and go hard after application or non-setting which remain flexible in use. The correct type of sealant should be selected. |
SealerAn undercoat that enhances adhesion by providing a barrier between the underlying paint and the new paint. Provides uniform colour holdout and an even, level surface for topcoat application. |
Sealing RingA rubber (or similar material) ring that fits in or against an item to make an air or liquid tight seal. |
Sealing StripGasket to prevent leaks. |
Search EngineA program that enables you to locate information on the World Wide Web using keyword searches. |
SeatA machined face for making a good seal when matched with a valve. |
Secondary BrakeBack up brake system, either mechanical or a split line hydraulic layout. |
Secondary CellsThe cells of a rechargeable battery. |
Secondary ShoeTrailing shoe in a drum brake. |
Secondary WindingThe high tension (secondary circuit) coil of wire in an ignition coil. |
SeedingThe development of tiny insoluble particles in paint (in the can) which results in a rough or gritty film. |
SEFISequential Electronic Fuel Injection. |
Seismic MassA small mass (weight) that moves to act as a sensing element. |
SeizureLock up of mechanical parts preventing or restricting proper movement. |
Selector ClutchPart of gear change system that automatically synchronises gear speeds before they are engaged. |
Selector ForkA fork that acts on, and moves a gear selector. |
Selector LeverAny lever to control a system that the driver uses to select a function. |
Selector MechanismThe mechanical connection between the driver and the gearbox shift hubs in a manual transmission. |
Selector ShaftSimple shafts that are attached to and move the selector forks, which in turn move the synchronisers. |
Self TestSee Self-Test. |
Self-AdjustingA mechanism or component that takes up free play automatically by either a mechanism or hydraulic pressure. |
Self-diagnosticsA system where the ECU can determine if an error has occurs in its own inputs, outputs or systems. |
Self-monitoringA system where the ECU can determine if an error has occurs in its own inputs, outputs or systems. |
Self-Servo ActionDescription of how the leading shoe on a drum brake system is pulled by the drum such as to increase its braking effect. |
Self-TestStart up and monitoring sequences for electronic control systems. Produce fault code data and triggers warning signals. |
Semi Floating AxleAn axle hub arrangement with one bearing mounted inside the axle casing where it supports the axle shaft. The load is carried by the shaft which has shear and bending forces applied to it. |
Semi-conductorA material that can be made to conduct or block electricity. A diode is a good example. |
Semi-elliptical SpringA suspension leaf spring consisting of one or more leaves with mounting eyes or slippers at the ends and having a curved shape. |
Semi-glossAn intermediate gloss level between high and low gloss. |
Semi-trailing ArmA rear suspension type with a triangular trailing arm that has the chassis mounting points set at an angle to the transverse axis of the vehicle. |
SemiconductorA material that can be made to conduct or block electricity. A diode is a good example. |
Sender UnitAnother name for a sensor. |
SensorElectronic components that send electrical signals to the ECU. |
SensorsElectronic components that send electrical signals to the ECU. |
SequenceOne thing that follows on to the next in time. |
Sequential Fuel InjectionA petrol fuel injection system using ported injection timed in sequence with the engine firing order. |
Sequential InjectionSee Sequential Fuel Injection |
Serial Fault ReaderEquipment that connects, usually to the OBD plug or similar, to read stored faults in an electronic system. See also scanner. |
Series CircuitAny electric circuit having all elements joined in a sequence such that the same current flows through them all. |
Series hybridAn engine drives a generator which in turn powers a motor that drives the vehicle. |
Series ResistorA resistor in a circuit that is connected in-line with the supply. |
Serpentine BeltA single flexible drive belt that provides a drive from the engine crankshaft to all ancillary components. Replaces a series of individual belts. |
ServoA servo mechanism (informal) |
Servo CylinderRam cylinder that supplements physical forces in operating a control (as for example steering, a brake or clutch), either by direct mechanical amplification or by external power assistance. |
ServomechanismSystem or device that supplements physical forces in operating a control (as for example a brake or clutch), either by direct mechanical amplification or by external power assistance. |
ServomotorA motor that supplements physical forces in operating a control. |
SESService Engine Soon (light) |
SettlingGravity separation of one or more components from a paint and the resulting layer of material on the bottom of a container. |
SFISequential Fuel Injection |
ShacklePart of a leaf spring suspension system that allows movement (swinging shackle) or is fixed to the chassis (fixed shackle). |
Shackle (Slipper)Allows for changes in length between the ends of a leaf spring as suspension moves. |
ShadeVariation of a colour. A colour that is basically blue can have a red shade or yellow shade as well as being blue. Shade is also called tone or undertone, since it describes the subtle tone of a colour. |
ShampooA cleansing agent consisting of soaps or detergents used for washing the hair – or a car! |
SheenThe gloss or flatness of a film when viewed at a low angle. |
Sheer ForceA force that tends to sheer or cut something much like the action of scissors. |
Sheet Moulded CompoundFibreglass or thermoplastic plastic material moulded to shape and used as an outer panel on a vehicle. |
Shell BearingsPlain bearing formed from two interlocking and abutting thin walled semi-circular cups. |
Shift ForkA fork that acts on, and moves a gear selector. |
Shift RingPart of a gear selector mechanism. |
Shift RodA simple rod that connects the gear change lever to the gearbox. |
Shift ShaftA shaft that is used as part of a gearshift / gear changing mechanism. |
Shift TimingThe point at which an automatic gearbox changes gear. |
ShimA thin metal sheet or washer used between two components to adjust free play. Shim material is produced in standard sizes. |
ShimmySide to side movement of the wheels that causes the tyres to lose some grip on the road. |
Shock AbsorberMethod of dampening suspension spring shock oscillation. Damper. |
Short CircuitA short circuit is one that allows a current to travel along a different path from the one originally intended. |
Short EngineEngine block containing crankshaft and pistons. Usually referred to when being replaced to overhaul the engine. |
Short MotorThe engine block and crankcase together with all internal running components, pistons, crankshaft, etc. |
Shrink FitAn interference fit obtained by heating the outer component or cooling the inner component so that they can be assembled with a push fit. When the temperatures are balanced the parts retain their interference fit. |
ShrinkageLoss of solvent during the drying/curing process of a paint film. |
ShroudGeneral term used to describe a cover. |
Shunt (Electrical)A parallel part of an electrical circuit. An example is the shunt windings of some starter motors. |
Side DraftA carburettor where the choke tube (venturi) is fitted horizontally. |
Side ThrustForces caused by cornering. |
Side-draught BoothA spray booth in which air movement is from the front to back. |
Side-toneViewing the repaired area from an angle just past the reflection of the light source. |
SiemensSiemens IT solutions and Services Ltd – Service provider for MOT Computerisation. |
Significant FiguresThe number of digits expressed in a measurement. Sig. fig. can appear before and/ or after the decimal point. |
Signposting Guidancewithin the specifications for the new AS levels A levels and GNVQs, opportunities for developing or producing evidence for assessment of key skills. |
Silencer (Muffler)A component in the exhaust system to absorb the gas shock waves and noise in order to reduce the emitted noise from a vehicle engine. Also known as a muffler.(US term). |
SiliconOne of many polymeric organic compounds of silicone with high resistance to cold, heat, water and passage of electricity. |
SiliconeA chemical compound with excellent water repellency and a slippery feel. Silicones are commonly used in automotive waxes to enhance application and ease of removal, and to increase gloss and durability. The term 'Silicones' is often applied to the defect known as 'cratering' or 'fish-eyes' |
Simple Gear TrainTwo or more gears in direct mesh. |
SimulationSimulation is the imitation of some real thing, state of affairs, or process. The act of simulating something generally involves representing certain key characteristics or behaviours of a selected physical or abstract system. |
SimulationsActivities that simulate or model reality. |
SimultaneouslyTwo or more things happening at the same time. |
Sine WaveThe wave pattern of an AC current. The positive and negative patterns are an inverse copy of each other. |
Single Point InjectionA petrol fuel injection system using a single point injector in a throttle body in the inlet air supply and positioned on top of the inlet manifold. Also throttle body injection (TBI)." |
SinkageA condition in which the topcoat appears to sink into the primer coat causing a loss of gloss. Also, a loss of gloss due to improper solvent selection. |
SinteringA manufacturing process using heat and pressure to form metal and composite components. Examples are brake lining materials and some components traditionally produced by forging or hot stamping. |
SipeVery narrow groove or cut in the tyre tread that aids the dispersal of surface water between the tyre and road. |
SIPSSide Impact Protection System |
SkidpanSpecial test track for skidding on! |
Skim-readingTo skim/scan text in order to get a general idea about it. |
SkinningThe formation of a thin, tough film on the surface of a liquid paint film, usually due to oxidation, hardening, or drying of the paint. |
SLA SuspensionShort and long transverse suspension arms. The upper arm is the shorter of the two. The geometry of this layout keeps the wheel camber reasonably constant during suspension movements. Also known as 'unequal wishbones'. |
Slave CylinderA hydraulic cylinder receiving a force and operating a mechanism. Examples are the clutch cylinder and the brake or wheel cylinders in brake units. |
Sleeve (Cylinder)A steel sleeve used to form a running surface for pistons in an engine. Also known as a cylinder liner. |
Sliding CaliperA brake caliper that has one piston and one sliding section. |
Sliding JointA drive shaft joint with the ability to change length and to transmit movement usually with a splined construction. |
Sliding ResistanceThe frictional value for the surface of a sliding component in contact with the track or road on which it runs. An example is the sliding resistance of a road tyre skidding on a road surface. The sliding resistance is usually less than the rolling resistance. |
Slinger(1) A plate fitted on a rotating shaft in front of an oil seal to reduce the volume and pressure of the oil on the seal. (2) A plate or protuberance on a crankshaft for throwing oil onto the cylinder walls or other components. |
SlipLoss of grip between two frictional faces. |
Slip AngleThe difference between the true line and the actual line of a vehicle wheel when cornering. |
Slip RingContinuous ring of copper used with a brush to transmit electricity through a rotating component. |
Sludge (Oil)Lubrication oil deterioration where the oil thickens, mixes with contaminants and forms a thick and glutinous jelly or paste. |
SludgingDescription of what happens to oil if it is not changed as recommended - a sludge forms that looks like Mississippi mud! |
Smart CardA card issue to an authorised user to access the MOT database via the VTS Device. |
Smoke MeterOpacity meter used to measure the amount of smoke in diesel engine exhaust gases. |
SNSpecial Notice – an official notice issued from time to time by VOSA to inform AEs, NTs and other system users of changes to the testing scheme. SNs may also be used to highlight areas of concern and to advise of developments of the scheme. |
Snail CamA cam that is shaped like a snail shell. In other words it has more effect the further it is turned. |
SnatchingTerm used to describe the action of a clutch when the take up is too sharp/severe. |
SOCState of charge (of a battery) |
Sodium HydroxideA chemical used as the inflater for some air bags. |
Soft Interface PadA support pad to which a finishing film abrasive disc can be attached. A soft interface pad reduces the pressure transmitted to the surface to be finished and moderates the cutting effect of the abrasive. Also used to great advantage on highly contoured surfaces. |
Soft Jawed ViceA vice with soft material fitted to the jaws to prevent damage to any components held in it. |
SoftwareA computer program. |
SOHCSingle Overhead Camshaft Engine. |
SolderA mixture of lead and tin used to join wires and terminals. |
Soldered JointTermination of cables with solder. |
SolenoidA coil of wire. Usually used to refer to a device containing an electromagnet. |
Solenoid SwitchElectro-magnetically activated electrical switch. |
Solenoid ValveA valve operated by a solenoid. Fuel injectors are good examples. |
SolidsThe part of the paint that does not evaporate but stays on the surface to form a film. Usually measured on a weight or volume basis. |
SolutionHomogeneous liquid or mixture of two or more chemical substances. |
SolvencyThe ability of a liquid to dissolve a solid. Measured by the viscosity of a solution at a certain concentration of solid resin. The same solvent may have different solvency for different resins. |
SolventA liquid which will dissolve another material, usually resins or other binder components. Commonly organic liquids. |
Solvent DensityThe weight per unit volume of a solvent or solvent mixture. |
Solvent-BlendThe particular mixture of liquids (usually true solvents and diluents) that give a paint the desired flow or evaporation properties. |
Solvent-borneDescribes a paint which contains organic solvents rather than water as its primary liquid component. |
Solvent-PoppingBumps or small craters that form on the paint film, which are caused by trapped solvent trying to escape through the drying paint. |
South PoleThe term used to describe one of the poles of a magnet where the magnetic field lines of force end. |
SpacerA metal sheet or washer used between two components to adjust free play. |
Spade TerminalA flat blade terminal used to make an electrical connection. |
Spark Ignition (SI)The ignition of petrol by a spark in the combustion chamber of an engine. |
Spark PlugsUsed to provide a small gap in the combustion chamber of an engine, for a spark to jump across. |
SpeakersDevice that converts audio signals to sounds that humans can hear. |
Specific GravityThe ratio of the density of a substance to that of water. |
Spell CheckerMost computer applications (i.e., Microsoft Word, Excel etc.) will enable you to check documents for incorrect spelling. |
SpellingTo form a word with a series of letters. |
SPISingle point injection. Electronic throttle body fuel injection system. |
Spider1. Arachnid with eight legs...2. Name sometimes used for the shaft on which planet gears rotate in a differential. |
Spider DiagramsA series of lines and boxes containing relevant information. A form of note taking. |
SpigotA bearing between two shafts mounted end to end axially. |
Spigot BearingBearing for a spigot shaft. Usually used to refer to the bearing inside the end of the crankshaft, into which the gearbox input shaft fits. |
SpindleA rotating shaft. |
Spindle Arm(1) Lever that imparts the steering action to the steering knuckle or stub axle assembly, as from a tie rod or track rod. Also steering arm, though this term is often used for the lever that imparts steering action from drag link to steering knuckle. (2) An intermediate arm in a steering system. |
Spindle BushesSimple bearings on which a spindle rotates. |
Spiral springThese are generally made of rectangular section material, flat strip, with round edges. They are general used as brush springs in D.C. motors. Also known as clock springs |
Spirit LevelA device full of liquid with a bubble that moves to the centre when it is level. |
SpliceA joint in two or more cables made by crimping or soldering the cables together. |
SplineAxial groove on a shaft and hub. |
Splined JointA toothed joint between two shafts that will transmit rotation but also allow axial (back and forth) movement. |
SplinesAxial grooves on a shaft and hub. |
Split PinA soft steel pin that has two sides that are folded out to secure the pin in a hole. Sometimes called a cotter pin. |
Split RingsTwo continuous rings of copper used with brushes to transmit electricity through to a rotating component such as an alternator rotor field winding. |
Split Slip RingTwo continuous rings of copper used with brushes to transmit electricity through to a rotating component such as an alternator rotor field winding. |
SplitterTool used to split ball joints or track rod ends from the steering arms. |
SpokesThin metal rods that join the wheel hub to the rim and support the weight of a vehicle. |
Spongy (Brakes)Usually caused by air in the hydraulic brake lines. A soft and imprecise feel to the brake pedal. |
Spot RepairA type of refinish job in which a section of the vehicle smaller than a panel is refinished. The paint is usually blended into the surrounding area. |
SPOUTSpark output Signal. |
Sprag ClutchA uni-directional rotary clutch that uses a series of shaped (like a figure 8) rollers and springs to either freewheel or grip the outer tracks to transmit a rotating force. |
Spray BoothAn enclosure used to paint vehicles. Spray booths have controlled air flow and normally have temperature control or baking capacity. |
Spray GunA device that mixes paint and compressed air to atomise and control the spray pattern as the paint leaves the fluid needle and air cap. |
SprayingPaint is atomised in a spray gun and the stream of atomised paint is directed at the part to be painted. Atomisation is normally achieved using high pressure air, by high fluid pressure, or by electrical means as in an electrostatic process. |
Spreader ValveThe adjustment valve on a compressed air spray gun which directs an air stream against the sides of an atomised paint cloud to adjust the spray pattern. |
SpreadsheetA computer program often used to create financial forecasting documents. |
Spring ClipSmall fixing device that can usually be removed by hand. |
Spring EyeA hole formed at the ends of leaf springs to allow fixing to the chassis. |
Spring RingSmall spring fixing device like a circlip. |
SprocketsGear wheels usually used to drive or be driven by a chain. |
Sprung Mass (Weight)The part of the vehicle supported by the suspension springs. |
Spur GearA gear wheel with straight cut teeth. |
Spurious DataData that falls outside what is expected. |
Square MetreThe area enclosed by a square with sides of 1 metre long. |
Square WaveThe wave pattern formed by a digital signal. |
SquealHigh pitched noise (screech) from friction components. Examples are brakes, clutch and drive belts. |
SqueegeeA flexible rubber blade used to wipe off excess water from washed or wet sanded areas. |
SquirmA twisting or side-to-side movement. |
SRIService Reminder Indicator. |
SRSSupplementary Restraint System. |
SRTSystem Readiness Test |
SSSpeed Sensor |
SSISolid State Ignition |
Stabiliser BarA torsion bar that connects the suspension on each side of a vehicle's axle to transmit movement from one side to the other in order to reduce vehicle roll when cornering. |
StabilizerAn additive included in a paint mixture to prevent degradation during storage. |
Stall SpeedThe maximum engine speed (rpm) of a vehicle with automatic transmission that can be obtained at full throttle against the brakes without moving the vehicle. A test procedure to check the torque converter. |
StallingWhen an engine stops because it is running too slowly or due to some other influence such as a learner driver! |
StampingA manufacturing process using punches and dies to cut objects out of sheet materials. |
Standard FormUsed so that very large or very small numbers can be written in a more convenient way. |
Standards moderationThe means by which awarding bodies ensure consistency across centres and ensure that national standards are being maintained and applied. |
Star Wound StatorAn alternator stator winding with the three-phase coils connected at the centre in order to give a large voltage output. The normal winding for light vehicle applications. Also 'Y' type stator. |
Starter MotorA powerful electric motor that produces high torque to rotate the engine for starting. |
Starter Solenoid FeedSmall wire that causes the solenoid to operate. Feed is from the starter switch and usually a relay. |
Starter SwitchThe switch that operates the starter motor. Usually part of the ignition switch. |
StaticA term that indicates components that are stationary. The opposite of dynamic when the components are in motion. |
Static BalanceThe balance of a rotating component about the rotational axis. Wheel balance has both static and dynamic quantities. |
StatisticsNumerical data. |
StatorStationary part of machine. Examples are the magnetic inductance component of an alternator and the reaction member in a torque converter. |
Stator WindingsElectrical windings on the stator of an alternator. |
STCSelf-Test Connector. |
SteelA ferrous metal commonly used as a substrate for paint, which must be painted to prevent corrosion. |
SteeringMechanism or means whereby the direction of a vehicle is controlled. |
Steering Arm(1) Lever that imparts the steering action to the steering knuckle or stub axle assembly, as from a tie rod or track rod. Also spindle arm (US), though this term is often used for the lever that imparts steering action from drag link to steering knuckle. (2) An intermediate arm in a steering system. |
Steering AxisThe point about which the steered wheel turns. |
Steering ColumnThe linkage and outer housing between the steering wheel and the steering gearbox/rack. |
Steering GearSmall pinion that operates the steering rack. OR Worm gear that operates a steering arm. |
Steering GearboxGearcase in which the rotary movement of the steering column is converted into angular motion of the drop arm or pitman arm. |
Steering Geometry(1) Position of the wheel and steering swivel mountings. (2) Combination of angles in steering swivel. |
Steering NutPart of a steering gearbox that moves on the worm gear. |
Steering RackSystem where a small pinion works on a flat gear (rack) to move the steering arms. |
Steering ShaftThe shaft that rotates as the steering wheel rotates. |
Steering SwivelThe turning component that carries the steered wheel, king pin, stub axle assembly and McPherson strut. |
StelliteHard and temperature resistant metal alloy used to coat exhaust valves. |
Stepper MotorAn electrically controlled motor that gives precise incremental movements. |
Stepper MotorsAn electrically controlled motor that gives precise incremental movements. |
STFTShort Term Fuel Trim |
STISelf-Test Input. |
STOSelf-Test Output. |
Stoichiometric RatioThe chemically correct ratio for air and petrol to achieve complete combustion. An air/fuel ratio of 14.7:1. |
Straight Line SanderSander that uses a back-and-forth movement to sand a surface using sandpaper on its shoe. |
StrainStrain is the amount of extension in size divided by the original length. |
StrainerA mesh filter for basic cleaning of oil or fuel. Usually fitted in the oil pan or fuel tank. |
StranglerAlternative term for a choke flap in a cold start device for a carburettor. |
Strap WrenchA tool used to undo filters. A simple strap tightens around the filter to grip it securely. |
Strap WrenchesSee Strap Wrench. |
StratifiedTo form, arrange, or deposit in layers. This usually refers to the fuel air charge in a cylinder where the layer next to the spark plug is richer than the layers further away. used for lean burn applications. |
Strength (of a pigment)The opacity and/or tinting power of the pigment. The measure of the ability of a pigment to hide or provide colour to a substrate. |
StressStress is a measure of a force or load divided by the cross-sectional area of a material to which the force is applied (N/m2). |
Striker PinPart of the door latch mechanism. |
Strippable CoatingAlso called booth coating. A sprayed peelable film which is applied to the internal walls of spray booths to provide protection from overspray. When the coating becomes sufficiently contaminated, it is easily peeled or scraped away and replaced by a new layer of strippable material. |
StroboscopicA flashing light. A strobe light is used to check and adjust ignition timing. |
Stroke (Cylinder)The length of travel of the piston in the cylinder. Twice the throw of the crankshaft. |
StrutTerm used to describe a suspension unit that operates telescopically. |
Stub AxleAlternative name for a king pin assembly or steering swivel. |
Stub Axle AssemblyAlternative name for a king pin assembly or steering swivel. |
StudThreaded rod. |
StyreneA low cost, colourless monomer which polymerizes readily. Widely used in the manufacture of fibreglass mouldings, plastic articles and polyester finishes. |
Sub-FrameAn extra chassis component used to support a major part such as the engine or transmission. |
SubstrateThe object or material to be painted. It may be bare metal, an old paint finish, or a foundation coating applied as part of a refinishing procedure. |
Suction-feed GunA spray gun that has the paint container connected directly below it. Air flowing across the air cap creates a vacuum and, thus, draws the paint up from the container via a metal tube. |
SumpLower part of an engine or gearbox usually containing lubrication oil. |
Sun WheelCentral gear wheel of an epicyclic gear train or differential. |
SunroofA fixed or operable (venting or sliding) opening in an automobile roof which allows light and/or fresh air to enter the passenger compartment. Sunroofs may be manually operated or motor driven, and are available in many shapes, sizes and styles. |
SuperchargerA mechanical air pump driven from the crankshaft and used to boost the intake air charge for an engine. |
SuperviseTo direct, manage, or oversee; to be in charge. |
Supplied-Air RespiratorA respirator that provides safe breathing air to a painter while working with paints. The air supply provides not only breathing air but positive pressure on the edges of the mask to eliminate any contaminants from the outside air. |
SuppressorAn electrical device fitted in parallel with a circuit to reduce the emission of electromagnetic waves at radio frequencies. |
Surface plateA flat metal plate for gauging the accuracy of a plane surface in precision metalworking |
SurfacerA heavily-pigmented foundation coating designed to be applied to a substrate for the purpose of smoothing or uniforming the surface for the subsequent coats of paint. Usually sanding is required, although non-sand variations are available. |
SuspensionMeans whereby vehicle body is supported on its undercarriage, comprising springs, dampers and locating linkages. |
Suspension ArmsLinkages used to construct a suspension system. |
SVCService connector for octane and idle speed adjustment. |
SwarfSmall pieces of metal that are produced during machining. |
Swash-plate CompressorSee swash-plate pump. |
Swash-plate PumpA type of pump that uses a rotating plate, that is radially off-set from the axis of the shaft, to operate the pump pistons in their cylinders. This design can also be used for compressors. |
SWBShort Wheel-Base |
Swept VolumeThe volume inside a cylinder above the piston crown at bottom dead centre minus the volume above the piston at top dead centre which forms the combustion chamber and is given the term 'clearance volume'. |
Swinging caliperA type of floating caliper with wedge-shaped disc pads (only one of which is activated by hydraulic pressure from the piston, the other being fixed), which can pivot on its hinge pin to equalize the pressure on both pads |
Swirl MarksA pattern of small scratches left in a finished surface by the wheel of a buffer or sander during the sanding and/or compounding operation, or by hand flatting using a circular motion. |
Switch PackGeneral term to describe a collection of switches in one unit, window lift switches in the driver's door for example. |
Swivel AxisLine about which the steering turns. |
Swivel JointsJoints used as part of a steering linkage about which the steering turns. |
Swivel PinsPins used as part of a steering linkage. Often called Kingpins. |
SymmetricalA description of objects that are the same on each side of their centre line. |
SymptomThe observed or measures result of a fault in a system. |
Synchromesh GearGear change system in which the speed of rotation of a selected gear is automatically synchronized with that of the mainshaft. |
Synchromesh HubCone clutches that are part of a gear change system which equalises the speed of a rotating gear. |
SynchroniseTwo or more occurrences happening or being made to happen at the same time. |
SynchroniserPart of gear change system that automatically synchronises gear speeds before they are engaged. |
SynchronizationAn adjustment that causes something to occur or recur in unison. |
SynchronizerPart of gear change system that automatically synchronizes gear speeds before they are engaged. |
SyntheticPrepared or made artificially, in contrast to naturally. For example, synthetic engine oil is NOT made from crude oil! |