DEFINITION OF TERMS - CONTINUED
Specific Gravity. The ratio of the weight of a substance
to weight of an equal volume of chemically pure water at
Steering Gear. That part of the steering system, located
at the lower end of the steering shaft, that carries the
rotary motion of the steering wheel to the vehicle wheels
Speed. Rate of motion.
Speedometer. An indicating device, usually connected
Steering Geometry. The difference in angles between
to the transmission, that indicates the speed of motion of
the two front wheels and the car frame during turns; the
inside wheel turns more sharply than the other wheel
turns since it must travel on an arc of a smaller radius.
Spider. In planetary gearsets, the frame, or part, on
Also called toe-out during turns.
which the planetary gears are mounted.
Steering Linkage. Linkage between steering gear and
Spiral Bevel Gear. A bevel gear having curved teeth.
Spline. A slot or groove cut in a shaft or bore; a splined
Steering System. The system of gears and linkage in
shaft onto which a hub, wheel, etc, with matching splines
the vehicle that permits the driver to turn the wheels for
in its bore is assembled so the two must engage and turn
changing the direction of vehicle movement.
Stoplight. A red light illuminated upon application of the
Spool Valve. A hydraulic control valve housing piston(s)
connected by a central rod.
Storage Battery. A lead-acid electrochemical device that
Sprag Unit. A form of overrunning clutch; power can be
changes chemical energy into electric energy. The
transmitted through it in one direction but not in the other.
action is reversible; electric energy supplied to the
battery stores chemical energy.
Springs. Flexible or elastic members that support the
weight of a vehicle.
The movement, or the distance of the
movement, in either direction, of the piston travel in an
Spur Gear. A gear with radial teeth parallel to the axis.
Starter. In the electrical system, the motor that cranks
Sulfation. A crystalline formation of lead sulfate on
the engine to get it started.
storage battery plates.
Sun Gear. In a planetary gear system, the central gear.
electrical power to the starting motor.
Supercharger. A device used in connection with engine
Starting System. The electrical system, including the
fuel-air systems to supply more air at greater pressure to
starter battery, cables, switch, and controls, that has the
the engine, thereby increasing volumetric efficiency.
job of starting the engine.
Superheat Switch. A switch used to disengage the
Accumulated electrical charges,
compressor during an overheating or loss of oil
usually considered to be those produced by friction.
Stator. A part of the torque converter that stands still as
Suppression. In the electrical system, the elimination of
torque is being multiplied, then rotates as the turbine
stray electromagnetic waves due to action of ignition,
approaches impeller speed.
generator, etc, so that they cannot be detected by radio.