Dictionary of Automotive Terms Abbreviations

DICTIONARY OF AUTOMOTIVE TERMS - "Se"

SE

Acronym for special edition.
An API designation for gasoline engines in passenger cars and some trucks beginning with 1972 and certain 1971 through 1979 models. Oils designed for this service provide more protection against oil oxidation, high temperature deposits, rust, and corrosion in gasoline engines than oils of SD classification which it replaced. It was replaced, in turn, by SF oil. These vehicles can benefit from the modern SM oils.

Seabee: A self-propelled sea barge larger than the Lash but using rollers to move aboard the ship

Sea chest: An opening for supplying seawater to condensers, pumps, etc. located in the hull below the waterline and having means for the attachment of the associated piping

Seal

A flexible ring, disc, or washer that prevents the passage of liquid, air, gas, or dirt.
To prevent the passage of liquid, air, gas, etc. by means of a seal or sealant (e.g., on seams, joints, flanges).
To coat a surface (e.g., when undersealing a car) by closing the pores of the anodic oxide layer in order to increase the resistance to staining and its effectiveness against corrosion

Also See
Apex seal
Cup seal
Door seal
Dynamic seal
Flange seal
Glass seal Grease seal
Lip seal with garter spring
Mechanical face seal
Mechanical seal
Oil seal
Piston seal Primary seal
Radial shaft seal
Rotating seal ring
Secondary seal
Shaft seal
Sillment seal Static seal
Stem seal
Valve guide seal
Valve oil seal
Valve stem seal

Sealant: An organic compounds (such as wax, oil, grease) used to protect seams or surfaces. Also called Cavity sealant, Mastic seam sealant, Sealer, Silicone-rubber sealant, or sealing compound

Sealed beam: See
Sealed beam headlight.

Sealed beam headlight: A Headlight Lamp in which the lens, reflector, and Filament are fused together to form a single unit. They are relatively inexpensive, but when one Component breaks, the whole unit is replaced. Newer vehicles use the more expensive Composite type with separate Bulb and lens which can be replaced individually in the event of failure. Only a few types of Bulbs are used in the Composite headlight, but the lens differs because it is shaped to the contour of the vehicle.

Sealed beam unit: A headlight that usually contains twin high/low filaments, a reflector, and a lens and is sealed to keep out dirt and moisture. When the headlight fails, you replace the entire unit. Sealed beam units are usually found on older vehicles. Newer ones have halogen headlights.
Also See
Sealed beam headlight.

Sealed bearing: A bearing that has been lubricated at the factory and then sealed, it cannot be lubricated during service. It is sealed to keep out contaminants.

Sealed bottom bracket: A Bottom bracket with protective seals to keep water and grime from penetrating to the bearings. Also called cartridge bottom bracket

Sealed pulley: A type of derailleur pulley that has sealed bearings

Sealed unit: See Hermetic system. Motor compressor assembly in which motor and compressor operate inside sealed housing.

Sealer

A substance you can add to the liquid in the Cooling system to seal leaks. Also called stop leak.
Other kinds of sealing Compounds are used to Coat surfaces before installing hoses or Gaskets. These are effective in preventing leakage but usually make the hose or gasket hard to remove.
An intercoat between the top Coat and the Primer or old Finish, giving better Adhesion.
Any material used to fill cracks and pinholes in a metal surface to be painted, applied before the base coat or as a base coat primer-sealer.

Also See
Body sealer
Room temperature vulcanizing sealer
Rust sealer

Sealing: See
PVC seam sealing

Sealing apparatus: See
Vacuum sealing apparatus
Seam sealing

Sealing bath: A hot water bath for the sealing treatment after anodizing

Sealing cell: See
Seam sealing cell

Sealing compound: See
Sealer
Underbody sealing compound

Sealing smut: Impurity deposit which forms after the anodized aluminum pieces are immersed in hot water

Sealing strip: Gas seal to the epitrochoidal surface in a rotary engine, with the same function as the piston ring on a conventional piston engine

Seal installer: See
Valve stem seal installer

Seal leak: Escape of oil and/or refrigerant at the junction where a shaft enters a housing.

Seal pliers: See
Valve stem seal pliers

Seal ring: See
Rotating seal ring

Seal with garter spring: See
Lip seal with garter spring

Seam: See
Inflation control seam
Mastic seam sealant
PVC seam sealing
Tear seam

Seamed tubing: Tubing made from steel strip stock that is curved until its edges meet, then welded together. Contrast Seamless tubing.

Seamless tubing: Tubing made from solid blocks of steel that are pierced and drawn into tube shape. Contrast Seamed tubing.

Seam sealant: See
Mastic seam sealant

Seam sealing: The sealing of seams, usually using organic compounds, to prevent the penetration of corrosive agents. Also see PVC seam sealing

Seam sealing cell: A flexible manufacturing cell in which seam sealers are applied

Seasonal energy efficiency ratio: (SEER) A measure of cooling capacity.

Seat

A surface upon which another part rests or settles. Example: the Valve seat is the matched surface upon which Valve face rests.
Minor wearing of the Piston ring surface during initial use. Rings then fit or seat properly against the Cylinder wall.
The cushions on which the Driver and passengers rest.
A metering control that is regulated by a Needle.

Also See
Automatic seat belt
Baby seat
Bead seat
Bench seat
Bucket seat
Child safety seat
Child seat
Conical seat
Flat seat
Front seat
Inertia reel seat belt Infant safety seat
Innerspring seat
Integral molded seat
Integrated child seat
Integrated child safety seat
Needle and seat
Power seat
Radius seat
Rear seat belt
Rim bead seat Rim bead seat taper
Rumble seat
Saddle
Safety bead seat
Solo seat
Split bench seat
Spring seat
Taper seat
Valve seat
Valve spring seat

Seat adjuster: A device which operates manually or electronically to move the position of the seat cushion forward or backward. It may tilt the front or back of the seat cushion up or down and may also move the seat back forward or back -- even to a reclining position. In some cases the adjuster will allow complete removal of the seat assembly.

Seat belt: Seat belt

A passive Restraint system which encircles the hips to prevent the occupant from being ejected from the vehicle. Often the seat belt is part of the shoulder harness. The use of seat belts is mandatory in every province and state in North America and in most every country.
Also See
Automatic seat belt
Inertial reel seat belt
Inertia reel seat belt
Rear seat belt
Three-point seat belt

Seat belt anchorage: The point where the end of a seat belt is attached to the body of a vehicle

Seat belt system: See
Seat-integrated seat belt system

Seat belt tensioner: A device that pulls the seatbelt tight in the event of a collision, taking up extra slack and reducing the force with which the occupant's body hits the belt. It is sometimes referred to as a pretensioner, though this implies that it deploys when a crash is imminent, which is misleading. Tensioners are generally tied into the same sensors that trigger the airbags and deploy at the moment of collision.

Seat belt warning light: A light on the dash which illuminates or flashes if the seat belts are not fastened.

Seat cluster: On a Bicycle, the conjunction of Top tube, Seat tube, and Seatstays near the top of the seat.

Seat cover clip: Seat cover clip

A spring steel clip used to secure the front seat sideshield and front seat back panel.

Seat covers: Trucker slang for attractive women in vehicles as in "Look at the seatcovers in that westbound rollerskate."

Seat cover S-hook: Seat cover S-hook

A steel hook used to secure the seat cover to the frame.

Seat cushion: The part of the seat upon which one sits or leans against.

Seat cutter: See
Valve seat cutter

Seat diameter: See
Bead seat diameter

Seat face: See
Valve seat face

Seat grinding: See
Valve seat grinding

Seating capacity: The number of people for which a vehicle is designed to carry.

Seat insert: See
Valve seat insert

Seat-integrated belt system: A seat belt with all belt elements and deflection points integrated in the seat; this improves occupant restraint in every seating position, but particularly sturdy seats and floorpans are required

Seat-integrated seat belt system: See
Seat-integrated belt system

Seat mat: See
Bead seat mat

Seat pan: See
Seat well

Seat panel: See
Under seat panel

Seatpost: On a bicycle, the part to which the Saddle clamps and which runs down inside the Seat tube.

Seatpost binder bolt: A bolt or quick release at the top of the seat tube used to hold the seatpost in place.

Seat rail: Tracks on which the front seat frame is mounted to provide fore and aft seat adjustment

Seat rail console: A mounting panel for the seat rails, spot-welded to the floorpan; the front consoles are usually somewhat higher than the rear ones to produce the desired angle of the seating surface

Seat ring: See
Valve seat ring

Sea trials: A series of test runs done at sea to determine whether the ship has met the specifications of design, modification, or repair

Seat runner: Tracks on which the front seat frame is mounted to provide fore and aft seat adjustment

Seats: See
Contre pente on both bead seats
Folding rear seats
Front seats
Split folding rear seats
Split rear seats

Seat skin: The covering (usually leather or vinyl) of the saddle on a motorcycle or bicycle.

Seatstay: On a Bicycle, one of the two parallel tubes that run from the top of the Seat tube back to the rear dropout.

Seatstays: On a Bicycle, the two parallel tubes that run from the top of the Seat tube back to the rear dropouts.

Seat taper: See
Bead seat taper
Rim bead seat taper

Seat tube: On a Bicycle, the tube that runs from just below the Saddle down to the Bottom bracket.

Seat well: A sheet metal panel to cover up the area below the car seats, especially below the rear seat bench

Sea worthiness: The condition of a vessel with regard to materials, construction, equipment, crew, and outfit which is considered safe for the trade in which it is employed

Seaworthiness certificate: A certificate issued by a classification society surveyor allowing a vessel with a mishap affecting its seaworthiness to proceed to another port where permanent repairs can be carried out.

Second: See
Second gear

Secondary: The high voltage side of the ignition system, usually above 20,000 volts. The secondary includes the ignition coil, coil wire, distributor cap and rotor, spark plug wires, and spark plug

Secondary air

In some exhaust emission control systems, e.g., thermal reactor or two-bed converter, secondary (outside) air is added to the exhaust to ensure sufficient supply of oxygen to promote oxidation of HC and CO, thus converting these pollutants into harmless water vapor and carbon dioxide.
Air externally supplied to the flame at the point of combustion.

Secondary air anti-backfire valve: A check valve that prevents exhaust system backfires from entering the secondary air system.

Secondary air bypass valve: An electronically controlled solenoid/vacuum valve that directs secondary air from the air pump to the atmosphere or to the secondary air switching valve.

Secondary air pulse valve: A valve activated by exhaust that uses the negative pressure pulses in the exhaust to draw secondary air into the exhaust system.

Secondary air switching valve: An electronically controlled solenoid/vacuum valve that directs secondary air from the pump to either the catalytic converter or the exhaust ports of the engine.

Secondary battery: See
Storage battery

Secondary brake shoe: See
Primary brake shoe
Trailing brake shoe

Secondary braking system: (HGV) A spring brake system which exerts force when air pressure is released

Secondary cell: See
Storage cell

Secondary circuit

The high Voltage part of the Ignition system.
The circuit which comprises the secondary winding of the ignition coil, the distributor, and the spark plugs

Secondary compression: A term that is used in Two-stroke engines. Primary compression takes place in the Crankcase and is then pushed up into the Combustion chamber where secondary compression takes place as the Piston squeezes the mixture. If the Crankcase seals are poor, Primary compression will be reduced resulting in reduced secondary compression so that it may be difficult to start the engine.

Secondary damage: See
Indirect damage

Secondary failure: The failure which occurs as a result of a primary failure (e.g., the primary failure is a flat tire caused by a nail hole; but as the tire continues to run flat, the secondary failure may be a tire roll-off where the tire comes off the rim). A good mechanic will search for the primary failure so that a secondary failure will not be repeated.

Secondary ignition: The high-voltage part of the ignition circuit, such as part of the ignition coil wiring, spark plugs, spark plug wires, distributor cap, and rotor. Compare Primary ignition

Secondary key: A key which operates only the locks needed for valet parking, i.e., door locks, ignition switch, and steering column lock; does not allow access to trunk, glove box, etc.

Secondary pattern: An oscilloscope pattern of the secondary circuit

Secondary piston

In a dual or tandem master cylinder, it is the piston which is normally pushed forward by fluid trapped between it and the primary piston.
In a tandem master cylinder, a floating piston which isolates the two braking circuits from each other and actuates the secondary circuit

Secondary pump: An oil pump driven via the gearbox output shaft. Compare Primary pump

Secondary refrigerating system: Refrigerating system in which the condenser is cooled by a different evaporator from the primary refrigerating system.

Secondary seal: A secondary piston seal in a tandem master cylinder

Secondary shoe

The shoe in a duo-servo drum brake assembly that is acted upon by the primary shoe. It provides more stopping power than the primary shoe (about 70%).
The rear shoe in a drum brake; often has longer lining than the other shoe.

Also see
Trailing shoe

Secondary visor: In a dual visor system, the main visor is moved to the side and the secondary visor is flipped down, thus shielding the driver from the sun from both the front and side

Secondary winding

An inner winding of the ignition coil; typically 20,000 to 30,000 turns of very fine wire. The opposite is primary winding
The secondary winding of an electric motor is a winding that is not connected to the power source but carries current induced in it through its magnetic linkage with the primary winding

Secondary wire: See
Secondary wires.

Secondary wires: The high Voltage wire from the Coil to the Distributor tower and from the tower to the Spark plugs.

Second gear: A middle gear which has a faster ratio than low gear, but slower than high gear. It is used for climbing or descending steep hills

Second law of thermodynamics: Heat will flow only from material at higher temperature to material at lower temperature.

Second rule: See
Two second rule

Section: See
Box section
Castle section
Channel section
Chassis section
Cowl section Cross section
Dogleg section
Front nose section
Midship section Phosphate section
Repair section
Scuttle section
U section

Section damage: See
Center section damage

Section height: The vertical measurement from the bead seat of a tire to the top of the crown when it is mounted, inflated and not under load. (Overall diameter less nominal rim diameter, divided by two.)

Section repair

Reinforcement made to the Casing when an injury has extended through the tread or sidewall of a tire. The damaged cord is removed and a new cord is replaced in the form of a repair unit or patch.
A major repair in the sidewall or tread of a tire. This repair unit must have cord material for reinforcement, made specifically for the type of tire -- bias-ply or radial.
An effective and economical repair method where extensive damage is confined to a specific section of the body shell and an undamaged section is taken from a vehicle which has been written off

Section width: The measurement across the tire width at the widest point when mounted and inflated (not under load), excluding any decorative moldings.

Sector: See
Worm and sector.

Sector shaft: See
Rocker shaft

Security system: See
Anti-theft system

Sedan: Sedan

The term sedan originally described a conveyance seen only in movies today -- a wheelless vehicle for one person, carried on poles by two men, one ahead and one behind. Automakers borrowed the word and applied it to cars with an enclosed four-door body type, permanent back panels, and top with full-width cross seats front and rear, and Passenger capacity from five to seven depending on Wheelbase. Longer-wheelbase models accept extra passengers in fold-down auxiliary seats. Sedans usually have quarter windows in the rear quarter in addition to windows in all four doors. Trunk racks often were standard offerings. Called saloon in U.K. According to Car and Driver, the term "sedan" refers to a fixed-roof car with at least four doors or any fixed-roof two-door car with at least 33 cubic feet (934 liters) of rear interior volume, according to measurements based on SAE standard J1100.

Also See
Close-coupled sedan
Convertible sedan
Four-door sedan
Imperial sedan
Landaulet sedan
Six-light sedan
Two-door sedan

Sediment: An accumulation of matter which settles to the bottom of a liquid.

Seebeck effect: When two different adjacent metals are heated, an electric current is generated between the metals.

Seed: A paint fault where a uniform distribution of small particles of regular size and pattern exist in a paint film. It is caused by contamination of the paint and poor filtration of the air lines. It is not to be confused with dirt contamination which is caused by dust settling on the painted surface before it has dried

Seek: A feature of a car stereo where the radio will find a requested station.

SEER: Acronym for Seasonal energy efficiency ratio.

SEFI: Acronym for Sequential electronic fuel injection

Seize

The condition when two items bond together so that they cannot be removed easily.
The condition when a piston bonds itself to the sides of the cylinder wall because of the lack of lubricant or overheating. See Freezing.

Seizure: See
Piston seizure

Selective absorber surface

Surface used to increase the temperature of a solar collector.
A solar absorber surface that has high absorbtance at wavelengths corresponding to that of the solar spectrum and low emittance in the infrared range.

Selective Catalytic Reduction: (SCR) Term frequently used as a synonym for catalytic reduction of NOx in diesel exhaust or flue gases by nitrogen containing compounds, such as ammonia or urea. Such SCR systems are commercially available for stationary applications and are being developed for mobile diesel engines. Since selective catalytic reduction is a generic term which also applies to other reactions, its use may lead to confusion in some situations.

Selective corrosion: The corrosion of alloys where the components react in proportions differing from their proportions in the alloys

Selective Oxidation: See
Preferential Oxidation

Selective transmission: The conventional Manual transmission of today in which any gear may be selected at will as opposed to the very early Progressive transmission in which the gears had to be selected in order.

Select-low principle

The method by which the rear brake application of an ABS brake system is monitored and controlled, based on the rear wheel with the least amount of traction
The controlling principle for rear-wheel anti-lock systems which states that pressure to both wheels shall be limited to the level required by the wheel with the least traction.

Selector: See
Gear selector indicator
Gear selector

Selector fork: Selector Fork

A part of the selector mechanism of a manual gearbox, shaped like a two-pronged fork, which fits into the groove round a coupling sleeve and moves a sliding pinion forward or back along a selector rod

Selector indicator: See
Gear selector indicator

Selector lever: An automatic transmission lever which permits the driver to adapt the gearchanging processes to particular road or driving conditions (slippery road surface, hilly terrain, towing) by choosing one of the drive ranges. Reverse, neutral, and parking lock are also selected by means of the selector lever

Selector lever lock: A device which locks the selector lever in Neutral or Park unless the driver depresses the brake pedal

Selector rod: A rod running the length of the transmission, along which the selector fork travels

Select valve: See
Air select valve

Self-adjusting: A mechanism that adjusts itself to compensate for wear or to maintain a certain distance or heat level

Self-adjusting drum brakes: A brake that automatically maintains the correct clearance between the lining and the drum.

Self-aligning torque: A Torque which is created by the tire when the vehicle corners. The force created at the tire Patch acts toward the rear of the actual center of the wheel. This action is called pneumatic trail. It has the same effect as positive Caster and can be increased by increasing the positive Caster. Thus the Trail distance (distance from the point at which the Cornering force acts to the center of the wheel or Steering axis) is a moment arm that results in a torque that tends to decrease the existing Slip angle and force the wheel back to the straight-ahead position. This self-aligning torque is transmitted through the steering mechanism to the Steering wheel and can be felt as steering effort or Road feel.

Self-cancelling indicator: All modern signal light switches (direction indicators) switch off automatically when the steering wheel is returned to the straight-ahead position

Self-centering: The forces in a steering system that set the front wheels straight when the driver's grip on the steering wheel is released after cornering

Self-centering effect: The forces in a steering system that set the front wheels straight when the driver's grip on the steering wheel is released after cornering

Self-cleaning: The ability of a spark plug to burn off the deposits of carbon and oil which build up due to tracking across the tip

Self-cleaning limit: The lower limit of the self-cleaning temperature, generally about 500°C

Self-cleaning tread: A tread pattern with tapered grooves and ribs, bars, etc., arranged in a manner that resists packing loose materials, (mud, etc.) in the grooves.

Self-contained: Having all essential working parts, except energy and control connections, so contained in a case or framework that they do not depend on equipment or fastenings outside of the machine.

Self-diagnosis: A test function in electronic engine management systems with a test program monitoring input and output signals, detecting errors and storing them permanently in a fault memory

Self-diagnostic code: The ECM can detect malfunctions in the CCC systems. If a malfunction occurs, the ECM turns on the check engine light. A diagnostic code can be obtained from the ECM through the check engine light. This code will indicate the area of the malfunction

Self-energizing: A brake shoe that is forced into the drum by the movement of the drum. A self-energizing shoe is mounted so its friction surface leads or is ahead of its pivot point.

Also See
Self-energizing brake shoe
Servo brake

Self-energizing action: The action of a rotating brake drum that increases the application pressure of the brake shoe(s).

Self-energizing brake: See
Single-anchor self-energizing brake

Self-energizing brake shoe: A Brake shoe (sometimes both shoes) that when applied develops a wedging action that actually assists or boosts the braking force applied by the Wheel cylinder. Also see Primary brake shoe.

Self-grip: See
Long-nose self-grip pliers

Self-grip pliers: See
Long-nose self-grip pliers

Self-ignition: The ignition of the air/fuel mixture in a diesel engine caused by high pressure and temperature. Different from a Spark ignition

Self-inductance: Magnetic field induced in conductor carrying the current.

Self-induction: This occurs when the current in an inductive circuit changes and the magnetic field cuts the conductors; this induced electromotive force opposes the change in current, restricting it if the current is increasing and enhancing it if the current is decreasing

Self-induction back-voltage: Back-voltage produced by self-induction. This induced electromotive force opposes the change in current, restricting it if the current is increasing and enhancing it if the current is decreasing.

Self-learning: See
Adaptive control.

Self-levelling shock absorber: See
Air shock absorber

Self-levelling strut: A suspension strut incorporating a shock absorber with a rubber boot filled with compressed air, serving as an auxiliary pneumatic spring

Self-levelling suspension: See
Automatic levelling.

Self-locking nut: A nut with a nylon insert that binds on the thread and resists vibration

Self-operating clutch: See
Centrifugal clutch

Self-parking: The ability of a car to park automatically, without any input from the driver; introduced by the VW Futura in 1991

Self-parking wiper: A windshield wiper that automatically returns to the (horizontal) park position when switched off

Self-priming pump: A pump which is able to evacuate and prime the suction pipe

Self-regulating sheathed-type glow plug: Originally a sheathed-type glow plug with a self-regulating heating coil, now with a heating and regulating coil

Self-starter: See
Starter motor

Self-sustaining ship: A containership fitted with her own crane for loading and discharging containers

Self-tapping screw: A screw which cuts its own threads as it is inserted into the hole

Self test: A part of functional diagnostic test procedure that verifies operation of sensors and actuators, detects hard faults, and stores information for later retrieval

Self-trimming ship: A ship whose cargo holds are shaped so that the cargo levels by itself.

Self-unloader: A bulk carrier which is equipped with cargo unloading gear

Self-vulcanization: Vulcanization at room temperature or above, activated by chemical agents without the application of heat from an outside source.

Selling: See
Fixed price selling
One price selling

Sem: A preassembled fastener, consisting of any type of screw or bolt, furnished with a toothed washer

SEMA: Acronym for Specialty Equipment Market Association, the aftermarket and Reproduction vehicle parts organization.

Semaphore indicator: Semaphore indicator

A signal light indicator used before flashers were introduced (such as on the Austin and Flying Standard), consisting of a lighted arrow that popped out from the side of the car (usually the B-post) when the turn signal switch was actuated. Also called trafficator

Semi: See
Tractor
Semitrailer

Semi-active suspension: A suspension whose characteristics can be tuned to driving conditions, such as by hydraulic adjustment of spring supports plus electronic correction of the damping rate

Semi-automatic frost control: Control which starts defrosting part of a cycle manually and then returns system to normal operation automatically.

Semi-automatic transmission: A transmission in which the clutch is disengaged and re-engaged automatically when the driver actuates the gear lever

Semi-Automatic valve: A valve that is opened manually and closed automatically, or vice versa.

Semi-centrifugal release finger: See
Clutch semi-centrifugal release fingers.

Semi-centrifugal release fingers: See
Clutch semi-centrifugal release fingers.

Semiconductor

A solid material such as silicon that has a resistivity midway between that of a conductor and a resistor, with properties of both a conductor and an insulator; used as substrates for semiconductor devices such as diodes, transistors, and integrated circuits
Any material that has a limited capacity for conducting an electric current. Certain semiconductors, including silicon, gallium arsenide, copper indium diselenide, and cadmium telluride, are uniquely suited to the photovoltaic conversion process.

Semiconductor ignition system: An ignition system that uses semiconductors for the switching operations

Semi-diesel: A semi-diesel engine operates on comparatively high compression and utilizes solid injection of fuel, however, it does use an electrical ignition system rather than depend solely upon heat generated by compression to furnish ignition

Semi-drop center rim: (SDC) A wheel rim having a demountable flange, for use on light commercial application. A slight depression in the center of the rim facilitates tire mounting and removal.

Semi-drop center rim taper: A wheel rim where both bead seats are tapered 5°.

Semi-drying oil: Those oils which are only partially hardened or are changed into a sticky mass when exposed to air and sunlight. The chief semi-drying oils used in paint, varnish, and lacquers are soybean oil, corn oil, and cotton-seed oil.

Semi-elliptic leaf spring: See
Semi-elliptic springs.

Semi-elliptic spring: See
Semi-elliptic springs.

Semi-elliptic springs: Semi-elliptic springs

A type of Leaf spring that takes its name from the shape which is part of an ellipse.

Semi-floating axle: Type of axle commonly used in modern vehicles. The outer end of the axle shaft does two things (1) it supports the weight of the vehicle and (2) it is the means of propulsion. The inner end of the axle shaft which is Splined, floats in the Differential gear. In this design a single bearing is placed between the axle shaft and the axle bearing; to remove the axle the wheel must first be removed.

Semihermetic compressor: Hermetic compressor with service valves.

Semi-independent suspension: A rear axle design with a torsionally flexible crossmember, the wheels being located on trailing links

Semi-metallic lining

Brake lining incorporating a high-percentage of metal in its composition.
A heavy-duty lining molded from iron powder, steel fibers, and organic binders works especially well at high temperatures.

Semi-race cam: A type of camshaft for race car engines which increases lift of valve, speed of valve opening and closing, length of time valve is held open, etc. Also called Full cam, Three-quarter cam, or Race cam, depending upon design

Semislick tire: A type of mountain bicycle tire with limited tread; popular for not-too-technical courses because it rolls faster than a knobby tire

Semi-tractor: See
Tractor.

Semi-trailer: A type of trailer that has wheels only at the rear, the front is supported by the towing vehicle or a dolly. See Trailer.

Semi-trailing arm: A type of Independent rear suspension where the pivot axes are usually at about 25 degrees to a line running straight across the car. This arrangement gives rear-wheel Camber somewhere between that of a pure Trailing arm (which has no Camber change relative to the body) and a Swing axle (which has large Camber change).

Semi-trailing arm suspension: See
Semi-trailing arm.

Semi-trailing link: An arm of a coil spring, independent rear suspension system which pivots at an angle to the centerline of the vehicle, thus imparting negative camber with increase in load. Also called Semi-trailing arm

Send: See
Guided send test

Sender: A sensor unit conveying information about an engine to a gauge, warning light, or other component. Also see Fuel tank sender

Sending unit: A device used for transmitting a signal to a gauge.

Send test: See
Guided send test

Sendzimir process: A continuous strip galvanizing process, named after its inventor. The strip is wound from a coil while the oil or grease adhering to it is removed by oxidation. It is then annealed, and the oxides are reduced by ammonia, after which it is cooled to 500°C and immersed in a zinc bath, which is kept molten at about 45O°C by the heat from the steel strip. On leaving the bath, the strip is cut and coiled

Senna, Ayrton: Ayrton Senna (full name Ayrton Senna Da Silva) of Brazil was, without question, the greatest race car driver in history. He was the embodiment of the professional race car driver. From his first appearance in a Grand Prix event in 1984, the racing world was on notice. The man was on a single-minded mission to win a World Championship title. No driver ever pursued this goal with such determination. Senna won his first title in 1988 and then again, two more times, in 1990 and 1992. He sat on the pole for more than 55% of all races he entered. Ayrton Senna was killed during the opening laps of the 1994 Grand Prix of San Marino at the Circuit Dino Ferrari near the town of Imola in Italy. His death was mourned the world over. Both Brazil and Japan took national holidays to mourn his passing. At the time of his death, Ayrton Senna was so significant to Brazil as a hero and source of income, he was responsible for nearly 20% of that country's gross national product. His body lay in state in the National Assembly before being buried with full state rights. At the time of this writing, rather pointless charges of manslaughter have been brought against the team Senna drove for at the time of his death. Frank Williams (the team owner), Adrian Newey (team Chief Designer) and Patrick Head (team Technical Manager) all face charges.

Sensible heat: Heat which causes a change in temperature of a substance.

Sensing: See
Electronic sensing device

Sensing device: See
Electronic sensing device.

Sensitive bulb: Part of sealed fluid device which reacts to temperature. Used to measure tem or to control a mechanism.

Sensitive limited slip differential: See
Torque sensitive limited slip differential

Sensor

An electronic detection device that receives and reacts to a signal, such as a change in voltage, temperature or pressure.
Material or device which goes through physical change or electronic characteristic change as surrounding conditions change.
Any device that receives and reacts to a signal, such as of a change in voltage, temperature, or pressure. Sends an input signal to a computer.

Also See
Absolute pressure sensor
Airflow sensor
Air sensor
Barometric pressure sensor
Boost sensor
Clearance sensor
Coolant temperature sensor
Crankcase position sensor
Crash sensor
Detonation sensor
Engine speed sensor
Engine temperature sensor
Ground clearance sensor
Hall-effect sensor
Hall sensor
Hego sensor
Impact sensor
Knock sensor
Lambda sensor
Low oil sensor
Magnet sensor
Manifold absolute pressure sensor
Oil level sensor
Oil pressure sensor
Oxygen sensor
Oxygen sensor system thermo-switch
Reference mark sensor
Rpm sensor
Throttle position sensor
Transistorized coil ignition with Hall sensor
Vacuum sensor
Wheel speed sensor

Sensor flap: A part of an airflow sensor which serves as a measure for the induced air volume; a potentiometer converts sensor flap movement into changes in electrical voltage, a form in which these signals can be evaluated by the fuel injection control unit

Sensor plate

A plate in the mixture control unit of a CIS, attached to a lever that operates the control plunger in the fuel distributor; the sensor plate position is governed by the amount of air admitted to the engine via the throttle valve and auxiliary air regulator
A round plate bolted to the air flow sensor lever which floats in the stream of intake air on the CIS type systems

Sensor system: See
Oxygen sensor system thermo-switch

Sensor system thermo-switch: See
Oxygen sensor system thermo-switch

Sentinel: See
Twilight sentinel

Sentra: Click image for books on
Sentra

A model of automobile manufactured by Nissan in Japan

SEO: Acronym for Special Equipment Option

Separate-application adhesive: An adhesive consisting of two parts; one part being applied to one face and the other part to the other face and the two faces brought together to form a joint

Separate chassis: The traditional body and frame design before the introduction of unitary construction; the body was lowered onto the chassis and bolted to it

Separate lubrication: An engine lubrication principle where the oil is no longer mixed with the fuel, but is fed by a metering pump from a separate oil tank to the engine components to be lubricated

Separation

The parting of retread rubber from the buffed Casing or the parting or debonding of any adjacent parts of the tire (ply to ply, ply to rubber, etc.), usually due to excessive heat.
After long storage, liquid ingredients of paints and fillers may separate in the can on top of the material; in most cases, this can be overcome by stirring the contents of the can thoroughly before use.

Also See
Bead separation
Ply separation
Tread separation

Separation solid tire: Rubber pulling away from steel bands.

Separator: Device to separate one substance from another.

Also See
Ball joint separator
Bearing separator
Envelope separator
Oil separator
Separators
Tie rod separator
Vapor separator
Water separator

Separator assembly-fuel vacuum: (SA-FV) fuel vacuum separator FVS

Separator, oil: Device to separate refrigerant oil from refrigerant gas and return the oil to compressor crankcase.

Separator plate: A solid piece of electrically conductive material (usually a metal or graphite) that is inserted between cells in a stack.
Also See
Valve body separator plate

Separators

Generally, anything that physically separates one part from another.
The wood, rubber, or plastic sheets or plates inserted between the positive and negative plates in a Battery to prevent contact.
A filter or trap.

Also See
Bearing separator
Oil separator
Vapor separator
Water separator

Sequence: The order in which events take place.

Also See
Cylinder sequence
Engine sequence test
Welding sequence

Sequence controls: Group of devices which act in series (one after another) or in time order.

Sequence test: See
Engine sequence test

Sequential electronic fuel injection: (SEFI) a computer controlled fuel system that distributes fuel through an injector located in each intake port of the engine. Each injector is fired separately and has individual circuits. Also called Sequential fuel injection (SFI)

Sequential fuel injection: (SFI) A computer controlled fuel injection system in which bursts of gasoline are sprayed into the intake ports by injectors at timed intervals. Each injector is fired separately and has individual circuits. Also called Timed fuel injection or Sequential electronic fuel injection (SEFI)

Sequential spark: See
Follow-up spark

Serial number: The individual, consecutive numbering of a product during production. It may be a combination of letters and numbers.
Also see
Batch number
Vehicle Identification Number

Series

A particular type of an automobile make and model. For instance, in 1952 Cadillac fielded three series a 62 (with a 126 inch Wheelbase); a 60 (with a 130 inch wheelbase); and a 75 (with a 147 inch wheelbase).
The alignment of electrical components. See Series circuit.
A numerical representation of a tire's aspect ratio. A 50-series tire has an aspect ratio of 0.50.
A method of connecting several parts in a row so that one feeds into the next.

Also See
Spec series

Series circuit

A circuit with two or more Resistance units so wired that the Current must pass through one unit before reaching the other. In contrast with Parallel circuit.
Electrical wiring; electrical path (circuit) in which electricity to operate second lamp or device must pass through first; current flow travels, in turn. through all devices connected together.

Series connection: A way of joining photovoltaic cells or batteries by connecting positive leads to negative leads to increase the voltage. Two twelve-volt batteries connected in series results in an output of 24 volts. Contrast Parallel connection where positive is connected to positive and negative to negative resulting in a stronger 12 volts (i.e., more amperage).

Series parallel circuit: See
Series-parallel circuit.

Series-parallel circuit: A circuit of three or more Resistance units in which a series and a Parallel circuit are combined.

Series resistance: Parasitic resistance to current flow in a cell due to mechanisms such as resistance from the bulk of the semiconductor material, metallic contacts, and interconnections.

Serpentine belt: A Poly-v-belt which wraps around several pulleys and idlers

Serrated shaft: A shaft with V-shaped grooves

Serration: A series of teeth on an edge (as on a saw)

Service

Periodic maintenance usually carried out by a garage; includes changing the oil and oil filter, checking the brakes, tires, ignition (usually changing the spark plugs), electrical, fuel and cooling systems, and taking the vehicle on a test run to check the steering, suspension, and transmission systems as well as the performance of the engine and brakes.
To carry out a service on a vehicle.

Also See
Breakdown service
Full service history

Serviceable hermetic: Hermetic unit housing containing motor and compressor assembly by use of bolts or cap screws.

Service brake

A foot-operated brake used for retarding, stopping, and controlling the vehicle during normal driving conditions
The primary brake system controlled by the brake pedal, operates the friction assemblies at all four wheels, and slows or stops the car in normal driving.

Service brake valve: A foot-operated unit which is used for graduated control of all the brakes in the service brake system.

Service codes: A series of two digit numbers that represent results of a self test

Also See
Trouble codes

Service Consultant: At many dealerships, the person responsible for receiving cars brought to the service department, in order to estimate the nature and cost of repairs and when the work will be completed. Also called Service writer

Service factor

(SF)

A measure of the overload capacity designed into an electric motor. A 1.15 SF means the motor can deliver 15 percent more than the rated hp without injurious overheating.
A multiplier that, when applied to the rated power, indicates a permissible power loading that may be carried under the conditions specified for service factor.

Service history: See
Full service history

Service hose: Specially manufactured hose designed to withstand the operating pressures of air conditioner system and equipped with threaded fittings that can be attached to service valves, manifold gauge sets, vacuum pumps, refrigerant containers, etc.

Service interval: The time or mileage between services (e.g., 12 months or 10,000 miles, whichever should come first)

Service life: The length of time a component or system will remain reliable and safe

Service manifold: Chamber equipped with gauges and manual valves, used by service technicians to service refrigerating systems.

Service manual: A handbook published by a vehicle manufacturer or a specialized publishing company that contains instructions and Specifications for the maintenance and repair of a specific car. It may include Wiring diagrams and Troubleshooting guides. Most service manuals deal with only one make, model, or year, and nearly all are intended for professionals or the very experienced amateur.

Service port: A fitting, on stem-type service valves and some control devices, to which manifold gauge set service hoses can be connected

Services: See
Special services

Service station: Outlets which sell gasoline and are operated by the major oil companies.

Service valve

Another name for either the high or low side service valves.
Manually operated valve mounted on refrigerating systems used for service operation.
Device used to check pressures, service, and charge refrigerating systems.

Also See
High-side service valve
Low-side service valve

Service writer: At many dealerships, the person responsible for writing repair orders (work orders) is the service writer. He communicates to the mechanic and service manager the problems in your vehicle that you have outlined. He also Estimates the nature and cost of repairs and gives you an idea when the work will be finished. Also called Service consultant

Servicing: To carry out a Service

Servo

A servo motor supplies power to a servo-mechanism. A servo-mechanism is a low-power device (electrical, hydraulic, or pneumatic) used to put in operation and control a more complex or powerful mechanism.
An oil operated device used to push or pull another part, such as tightening the Transmission Brake bands.
Any system used to assist a mechanism to operate with greater force than that initially applied to it.
Abbreviation for Servomechanism

Also See
Brake servo unit
Brake servo
Master vac servo unit
Vacuum servo

Servo action: Describes how one brake shoe adds to the application force of the other.

Servo action brake: See
Servo action brakes.

Servo action brakes: Brakes so constructed as to have one end of the primary shoe bearing against the end of the secondary shoe. When the brakes are applied, the primary shoe attempts to move in the direction of the rotating drum and in so doing applies force to the secondary shoe. This action, called servo action, makes less Brake pedal pressure necessary and is widely used in brake construction.

Servo-action drum brake: See
Duo-servo drum brake.

Servo-assisted: See
Power-assisted

Servo brake

A drum brake in which the shoes are arranged so that one shoe helps to apply the other, to create a self-energizing effect in both shoes
A drum brake in which brake shoes are linked, such that the braking force of one shoe amplifies the input of the other shoe(s).

Servomechanism: A device that provides power assistance to operate a control (e.g., a brake or clutch)

Servo motor

A small electric motor that supplies power to a Servomechanism
A calibrated vacuum or electrical motor used to position valves or doors in an automotive air conditioning system.

Servos: Servos apply certain mechanical functions. For instance, if first gear is actuated by the application of a band, the servo is what applies that band. The servo is nothing more than a piston that is connected to a mechanical linkage, moved by hydraulic pressure. When the need for a certain application arises, oil pressure moves the servo and the servo makes the application.

Servo unit: See
Brake servo unit
Master vac servo unit

SES: Acronym for Service Engine Soon obsolete term replaced by MIL

Set

To adjust (e.g., a screw) to a standard.
To allow to harden (e.g., body filler, glue, etc.).

Also See
Aligning set
Bracket set
Contact set
Planetary gear set
Straightening set

Setback Axle: The front steering axle moved rearward from the generally accepted standard position. Advantages Shorter turning radius and more of a vehicle's weight shifted to the front axle.

Setting time: The time required for a adhesive, sealer or coating to approach maximum strength and firmness as it dries or sets.

Set screw: A fully threaded bolt with a parallel shaft. It is used to secure metal parts together (such as a hub or wheel to a shaft); can have a variety of heads, the most common being hexagonal, round or countersunk

Setter hammer: See
Tile setter hammer

Setting

Adjustment.
Hardening.

Also See
Basic ignition setting
Beam setting
Headlight beam setting

Settle: To sink to the bottom (of a liquid). The weight of the pigments in a paint varies greatly depending on their color. Heavy pigments give color, opacity, and specific properties to the paint. Some pigments weigh seven or eight times as much as the liquid part of the paint and because of this, they tend to settle to the bottom of the container

Settling: The Pigment in the paint collecting at the bottom of the spray gun container.

Set-up

Premature vulcanization of a rubber compound during processing or storage.
The action of a gel-like substance which goes from a liquid to a rubbery solid or when a paste turns solid.

Seven: See
Group of seven

Seventy-five (Cadillac): A 1936-76 Cadillac vehicle brand of which the Sedan/Limo for 1946-70 are Milestone cars. Also see history of Cadillac.

Seville: Click image for books on
Seville

A model of automobile manufactured by the Cadillac division of General Motors from 1975 to 2004. The name was also used on some Eldorados as Eldorado Seville from 1956 to 1960.

Sew up tire: See
Sew-up tire.

Sew-up tire: A Bicycle tire with an Inner tube stitched inside the casing; also known as a tubular.