| g
| Green. |
| g-force
| the force that is exerted on a vehicle during acceleration, deceleration, or corning, expressed in units of gravity (g's). |
| G.I. spacer
| A device used to space out a piston ring in a piston groove that has been intentionally machined oversize because of wear. |
| G/R
| Gear reduction |
| Ga
| Gallium An element with the atomic number of 31 |
| gage
| 1. A less popular way of spelling gauge. 2. An element used to contain and space the rollers in a one-way roller clutch. |
| gain
| Any increase in the current, voltage or power level of a signal. 2. The ratio of output to input signal level of an amplifier. |
| Gain Accuracy
| An indication of how accurately the vertical system attenuates or amplifies a signal, usually represented as a percentage error |
| gallery
| A passageway inside a wall or casing, such as for oil circulation. |
| galling
| 1. The friction-induced roughness of two metal surfaces in direct sliding contact. 2. The welding up and tearing sown of metals due to extreme high temperature and/or inadequate lubrication. |
| galloping hinge
| A connecting rod. |
| galvanic action
| the action of electropositive and electronegative metals due to the wasting away of the positive metal. This is most noted when iron (Fe) and brass, copper (Cu), or copper (Cu) and zinc (Zn), are in contact in the presence of acid-diluted water. |
| galvanic battery
| A D/C voltage source generated by the chemical action of an electrolyte. |
| galvanic reaction
| An electrical reaction caused by heat and water passing through metal pipes or parts at high speeds. |
| galvanize
| An electro mechanical process of coating zinc (Zn) to ferrous metals to reduce or prevent rust. |
| galvanometer
| An instrument used for measuring a small electrical current. |
| gap
| The space between two adjacent parts or surfaces. |
| garbage in, garbage out GIGO
| A famous computer axiom meaning that if invalid data is entered into a system, the resulting output will also be invalid. |
| gas
| 1. A state of matter 2.A vapor. 3. A short term for gasoline. |
| gas bypass line
| A term used for hot-gas bypass line. |
| gas bypass valve
| A term used for hot-gas bypass valve. |
| gas cylinder
| A mainarea used for the transportation and storage of compressed gas. |
| gas defrosting
| The use of hot, high-pressure gas in the evaporator to remove frost or ice buildup. |
| gas fade
| Brake fade due to hot gases and dust that reduce friction between the drum or rotor during prolonged hard braking. |
| gas guzzler
| A vehicle having excessive fuel consumption. |
| gas hog
| A term often used for gas guzzler. |
| gas ports
| A series of holes drilled from the crown of a piston to the top ring groove, providing combustion pressure to force the ring against the cylinder wall, ensuring a more effective seal. |
| gas regulator
| A device used to control the delivery of gas at a substantially constant pressure. |
| gas shock
| A term used for gas-filled shock absorber. |
| gas-filled shock absorber
| A shock that uses nitrogen gas, at 25 times atmospheric pressure, to pressurize the fluid in the shock to reduce or prevent aeration or foaming. Also known as gas shock. |
| gas-metal arc welding (GMAW)
| An arc-welding process that uses an arc between a continuous-filler metal electrode and the weld pool. |
| gas-transfer velocity
| The speed at which the air-fuel mixture spreads out in the combustion chamber during the power phase. |
| gas-tungsten arc cutting (GTAC)
| An arc-cutting process that uses a single tungsten electrode with gas shielding. |
| gas-tungsten arc welding (GTAW)
| An arc-welding process that uses an arc between a non-consumable tungsten electrode and the weld pool. |
| gas-turbine engine
| An internal-combustion engine in which the shaft is spun by combustion gases flowing against curved turbine blades located around the shaft. |
| gasifier section
| The part of a gas-turbine engine that draws in air, mixes it with fuel, and burns the mixture. |
| gasket
| 1. A metal ring used on some spark plugs to seal pressure between the plug shell and the cylinder head. 2. A piece of thin compressible material such as cork, rubber, or soft metal, placed between two mating surfaces to form a seal. |
| gasket cement
| A liquid gel or paste adhesive material used to bond gaskets to their mating surfaces. |
| gasket shellac
| A liquid form of gasket cement. |
| gasohol
| In the United States the term gasohol refers to gasoline which contains 10 percent ethanol. This term was used in the late 1970's and early 1980's but has been replaced by terms such as Super Unleaded Plus Ethanol or Unleaded Plus. |
| gasoline
| A liquid blend of hydrocarbons used as automotive fuel and processed from crude oil. |
| Gasoline Alley
| The infield-garage area at the Indianapolis speedway. |
| gasoline consumption
| A term used for fuel consumption. |
| gasoline mainarea
| Specially approved OSHA mainareas used to safely hold and store gasoline. |
| gassing
| The conversion of battery water into hydrogen and oxygen gas. |
| gate
| 1. A digital circuit with several inputs and one output that performs a logical function such as AND, OR, NOT, NAND, or NOR. 2.The money that is collected for admission. 3. The starting position for a drag race. 4. To take the lead in a drag race right from the start. |
| gauge
| 1. An instrument used for measuring, such as for compression. 2. A dashboard-mounted component used for visual indication of engine and system conditions, such as oil pressure. |
| gauge pressure
| A pressure indicated on a scale with atmospheric pressure as 0 psi or kPa. |
| gauge set
| 1. Two or more instruments attached to a manifold and used for measuring or testing pressure. 2. Two or more instruments used to indicate engine and system conditions, such as oil pressure, coolant temperature, and charging-system indicators. |
| gauging point
| The starting point for measuring a part. |
| Gauss's Law
| Karl Friedrich Gauss (1777 - 1855) A German mathematician knowen for his work in magnetism. Gauss's Law stats that the total of the electric flux out of a closed surface is equal to the charge enclosed devided by the permittivity. |
| GAWR
| An acronym for gross-axle weight rating. |
| GCM
| Governor control module |
| GCW
| An acronym for gross combined weight. |
| Gd
| Gadolinium An element with the atomic number of 64 |
| Ge
| Germanium An element with the atomic number of 32 |
| gear
| 1. A cogged device that mates or meshes with another. 2. One's personal belongings and/or equipment. |
| gear backlash
| The measurable gap or slack between gears. |
| gear carton
| A transmission housing. |
| gear drive
| A system of two or more gears, such as one that transmits power from the crankshaft or camshaft. |
| gear lubricant
| A type of oil or grease especially formulated to lubricate gears. |
| gear oil
| A thick lubricant, generally with an SAE number of 80 or above, used in standard transmissions or differentials. These often contain additives, such as an EP additive, to guard against being squeezed out from between gear teeth. |
| gear oil, limited-slip
| A lubricant specified for use in certain limited-slip differentials to prevent chattering during turns and/or abnormal wear to the parts. |
| gear pitch
| The number of teeth in a given unit of pitch diameter. |
| gear pump
| A positive-displacement pump that uses an inner drive gear and an outer driven gear, separated on one side by a crescent, to produce oil flow. Gear pumps may use either helical or spur gears and are sometimes called gear-and-crescent pumps. |
| gear ratio
| 1. The speed relationship that exists between a driving (input) and a driven (output) gear. For example, a driving gear that revolves twice for each driven-gear revolution has a 2 to 1 (2:1) ratio. 2. The number of turns, or revolutions, made by the drive gear compared to the number of turns made by the driven gear. |
| gear reduction
| A condition in which the drive gear rotates faster than the driven gear. Output speeds of the driven gear is reduced, while output torque is increases. |
| gear rotor pump
| A type of pump that uses sun gears to move liquid. |
| gear shift
| 1. A floor- or steering-wheel-mounted lever used to manually change gears in the transmission. 2. A linkage-type mechanism by which the gears in a transmission are engaged. |
| gear whine
| A high-pitched sound developed by some types of meshing gears. |
| gear-type pump
| A pump that uses two rotating gears to draw in fluid that is carried around the outer pump body in cavities between gear teeth and dispensed under pressure as the gear mesh together. |
| geared speed
| A theoretical vehicle speed based on engine rpm, transmission-gear ratio, rear-axle ratio, and tire size, not accounting for slippage. |
| gears
| Mechanical devices containing teeth that mesh that transmit power, or turning force, from one shaft to another. |
| geartrain
| A series of two or more gears meshed togather so that power is transmitted among them |
| gel coat
| The first layer that is applied to a female mold for a fiberglass layup, before the mat or cloth layers. |
| GEM
| Governor electronic module |
| GEN III system
| A fuel and engine ignition-management system developed in the late 1980s by General Motors. |
| general engine specifications
| Specifications that are used to identify a particular style and type of engine. |
| general over-the-road use
| A fifth wheel truck designed for pulling multiple standard duty highway equipment such as trailers, flat beds, tankers, and so on. |
| general purpose (GP)
| A military designation during World War II, for the Willys 4x4; later known as a Jeep. |
| Generating Capacity
| 1. The maximum amount of electric power produced by a generator. |
| generator
| 1. A machine that converts mechanical energy into electrical energy. 2. A source of signals that are transmitted, amplified, of manipulated by electronic circuits. |
| geometric centerline
| A static dimension represented by a line through the center of the vehicle from front to rear. |
| Georg Ohm
| Georg Simon Ohm (1787 - 1854 ) a German Physicist for whom the measurement of resistance is named for and his laws of circuit calculation are famous |
| Germanium
| [1] A semiconductor material that contains exactly four electrons in its valance shell [2] An element in the periodic table #32 with 4 electrons on its valance shell a semiconductor used to manufacture semiconductor sevices |
| gerotor
| A term used for gear rotor pump. |
| get off it
| To release the accelerator and slow down. Also known as get out of it. |
| get out of it
| To release the accelerator and slow down. Also known as get off it. |
| get with the program
| To perform a task properly. |
| giga
| the prefix representing the number 1,000,000,000 |
| GIGO
| an acronym for Garbage In, Garbage Out: A famous computer axiom meaning that if invalid data is entered into a system, the resulting output will also be invalid. |
| gilhooley
| To spin out on a dirt track. |
| gilmer belt drive
| An accessory drive system using a cogged belt to ensure positive engagement, such as with a supercharger. |
| gingerbread
| Non-functioning visual ornamentation, such as chrome. |
| girdle
| A heavy-duty, main-bearing support for a racing engine. |
| gladhand
| Connectors between tractor and trailer air lines. |
| glass
| 1. A term used for fiberglass-reinforced plastic. 2. A hard, brittle, transparent substance composed of silicates mixed with potash or suds and lime; used for windows in a vehicle. |
| glass beadier
| An apparatus for using air-propelled glass beads to clean parts. |
| glass wrapped
| A term used to refer to a vehicle with a fiberglass body. |
| glass-bead cleaning
| the cleaning of parts and panels using glass beads propelled with the use of compressed air. |
| glass-bead test
| A method of determining the absolute rating of a filter and its efficiency by introducing a measured quantity of glass beads of varying, but known, diameter, as a contaminant into the fluid, which is then filtered through the element. |
| glaze
| A smooth, glossy surface. |
| glazed
| Polished by heat and friction to a hard, smooth, shiny surface, unlike the original surface finish. |
| Glitch
| An intermittent, high-speed erroe in a circuit |
| global warming
| The gradual warming of the earth's atmosphere due to the greenhouse effect. |
| gloss
| An appearance characteristic that gives the perception of the brightness and luster of a smooth, polished surface. |
| glove box
| A small, enclosed storage area in the front passenger compartment of a vehicle. |
| glove compartment
| A term used for glove box. |
| glow plug
| An electrical plug used to preheat the combustion chamber to aid in starting a cold diesel engine. |
| Glyptal
| A specific brand of Class F insulating enamel. |
| GM
| General Motors |
| GMAC
| An acronym for gas-metal arc cutting. |
| GMAPPA
| Governor manifold absolute pressure per altitude |
| GMAW
| An acronym for gas-metal arc welding. |
| GMC
| General Motors Corporation |
| GMC supercharger
| A positive displacement, mechanically-driven blower developed by General Motors for two-stroke, diesel-truck engines later adapted for gasoline racing engines. |
| GMM
| An acronym for Graphing Multi Meter |
| GN
| An acronym for Grand National. |
| go button
| The accelerator. |
| Go Kart
| A term for a specific brand of racing kart, often used as a generic term for any kart. |
| goat
| A term used to identify a Pontiac GTO. |
| gobble
| To run extremely fast. |
| gofer
| 1. Go for. 2. A person who runs errands. |
| gold
| A trophy. |
| good trip
| trip counters in which various monitors have passed testing under predetermined conditions. The fulfillment of specific test parameters during a drive cycle. Good trips are counted for MIL extinguishing and DTC erasure. |
| goodies
| 1. Prizes and awards for race-car winners or show-car participants. 2. High performance equipment on an engine. |
| goosed moose
| A car having a severe forward rake. |
| gourd guard
| A helmet. |
| governor
| 1. A device that controls another device, usually on the basis of speed or rpm. 2. A speed-sensitive mechanical assembly in the automatic transmission driven by the output shaft, to supply primary control of when shifting is to occur. |
| governor assembly
| A vehicle speed-sensing device that produces governor pressure to force the transmission upshift and permit the downshift. |
| governor pressure
| the transmission's hydraulic pressure, used to control shift points which is directly related to output shaft speed. |
| governor valve
| A device attached to the output shaft and used to sense vehicle speed. |
| gow job
| A term used in the early 1940s to identify a hot rod. Also gow wagon. |
| gow out
| To accelerate quickly in a gow job. |
| gow wagon
| A term used in the early 1940s to identify a hot rod. Also gow job. |
| GP
| 1. An acronym for general purpose. 2. An acronym for Grand Prix. |
| GPB
| General purpose braided |
| GPH
| An acronym for gallons per hour. |
| GPM
| An acronym for gallons per minute. |
| GPS
| An acronym for Global Positioning System. A global tracking system that tracks or locates the position of a sending device through global satellites. Used by individuals to locate there position any ware in the world and used by companies like trucking companies to track the position, speed, and milage of there vehicles. |
| GPT
| General purpose thermoplastic |
| gr
| Grey. |
| grade
| 1. A hill; generally a step hill. 2. Sort by size or quality. |
| grade labeling
| Tire ratings that may be used as a guide in buying, enabling the buyer to compare, at a glance, the apparent value of one tire with that of another. |
| gradeability
| The ability of a truck to negotiate a given grade at a specified GCW or GVW. |
| gram
| A metric unit of weight measurement equal to 1/1000 kilogram ( 1oz x 28 = 1 gram). An American dollar bill or paper clip weighs about 1 gram. |
| grams-per-mile
| A measurement of the amount of exhaust emissions a vehicle produces. |
| gran turismo (GT)
| Italian for "grand touring." |
| gran turismo omologato (GTO)
| Italian term for GT cars the have been qualified for racing as a production vehicle. |
| Grand National
| A premier series of NASCAR stock car races. |
| Grand Prix (GP)
| 1. A French term that means "grand prize." 2. An international series of Formula One racing events. 3. The 24-hour race at LeMans. 4. An annual USAC midget-car race once held on Thanksgiving in Southern California. |
| grand touring
| A sports coupe with enclosed, rather than open, bodywork. |
| granny gear
| The combination of low gear in the transmission and low range in the transfer case. |
| graphical user interface GUI
| A program interface that takes advantage of the computer's graphics capabilities to make the program easer to use such as Microsoft Windows. |
| graphics
| Any computer-generated image or illustration produced on a screen, paper, or film. |
| graphite
| A crystalline form of carbon (c) found in natural deposits or formed by eating black carbon (C). |
| Graticule
| The grid lines on a screen for measuring oscilloscope traces patterns or waveforms |
| gravity bleeding
| A method of purging air from a system by allowing the fluid to force air out of an opened bleeder valve by its own weight. |
| gravity casting
| A process that relies on gravity to pull the material to the bottom of the mold during casting. |
| gravity energized
| A one-way roller clutch that has no mechanical means for holding the roller in contact with the cam and race. |
| gray market
| The individual importing of a foreign car into the United States. |
| gray water
| Used wash water from the kitchen and bathroom of a mobile home or recreational vehicle. |
| gray-market parts
| Any part that is not covered by a manufacturer's warranty, generally because it was not sold through an authorized dealer. |
| grease
| Lubricant consisting of a stable mixture of oil, soap thickeners (usually lithium, sodium, or calcium), and other ingredients for the desired physical or operating characteristics. |
| grease fitting
| The orifice, having a check valve, that a grease gun fits on during the greasing process. |
| grease plug
| A small plug in a lubrication hole where there is a danger of over lubrication by high-pressure equipment. It is removed for lubrication and then reinstalled. |
| greasy friction
| The friction between two surfaces coated with a thin layer of oil. |
| green
| 1. Aq color. 2. A term used for green flag. |
| green flag
| The flag used to signal the start of a race. |
| green goo
| A term used for green Loctite. |
| green Loctite
| A high-temperature anaerobic compound used for securing parts together. |
| greenhouse
| The upper part of a vehicle body, including the windows, pillars, and roof. |
| greenhouse effect
| A greenhouse is warmed because glass allows the sun's radiant heat to enter but prevents radiant heat from leaving. Global warming is caused by some gases in the atmosphere that like greenhouse glass, hence, the term greenhouse effect. |
| grenade motor
| An engine that is expected to deliver a very high horsepower for a short time, before it blows up. |
| grenaded motor
| An engine that has blown up. |
| grid
| 1. A wire mesh, such as that used for a grille. 2. The starting position of race cars based on their qualifying order. |
| grid growth
| A condition where the battery grid grows little metallic fingers, extending through the separators, shorting out the plates. |
| grille
| An ornamental opening in the front of a vehicle through which air is delivered to the radiator. |
| grind
| 1. To use an abrasive wheel to remove metal. 2. The specific contour of a camshaft lobe, such as a quarter-race grind. 3. A long race with emphasis on endurance rather than performance. |
| grip
| A term used for traction. |
| grit
| Fine dust or dirt. |
| grocery getter
| A car used for everyday transportation. |
| grommet
| 1. A reinforced-metal eyelet through which a fastener is attached. 2. A rubber or plastic eyelet inserted in a hole to protect wires that pass through it. |
| groove
| 1. The recess in a part to hold a ring or snap ring. 2. Space between two adjacent tread ribs or lugs; the lowered section of the tire tread. 3. The specific path through a turn in an oval track or in road racing. 4. A rut. |
| groove weld
| A weld made in a groove between the work pieces. |
| gross axle-weight rating (GAWR)
| The maximum allowable fully loaded weight of a given axle. |
| gross combination weight (GCW)
| The total weight of a fully equipped vehicle including payload, fuel, and driver. |
| gross horsepower
| The maximum engine output as measured on a dynamometer. Also known as gross torque. |
| gross torque
| A term used for gross horsepower. |
| gross trailer weight (GTW)
| The sum of the weight of the trailer(s) and the payload. |
| gross valve lift
| The valve lift, including the running-valve clearance. |
| gross vehicle-weight rating (GVWR)
| The maximum that a vehicle should weigh when fully loaded with all passengers, fuel, and cargo. |
| ground
| 1. The common return path for electric current in a system, component, or vehicle. 2. A reference point connected to or assumed to be at zero potential with respect to the earth. 3. The lowest possible voltage potential in a circuit. |
| Ground Controlled Circuit
| A circuit which energizes by applying a ground usually through a control module |
| ground effect
| The reduced air pressure under a vehicle that allows the normal pressure above the vehicle to push the vehicle downward, providing a better grip on the road surface. |
| ground electrode
| A part of the lower end of the spark-plug shell making up the electrode gap, providing a path for current flow while jumping the gap. |
| Ground Trace
| The part of a waveform that defines the circuit ground |
| ground wave
| An electromagnetic wave that travels along the Earth's surface; usually emitted by a radio transmitter. |
| ground-end spring
| A spring that has flattened ends, usually by grinding, to better fit the perches or retainers. |
| ground-return system
| A common system of electrical wiring whereby the chassis or frame serves as a part of the electrical circuit. |
| grounded
| Connected to Earth or to some conducting body that serves in place of the Earth. |
| grounded circuit
| A condition that allows current to return to ground before it has reached the intended load component. |
| grounding
| The connecting of an electrical unit to the vehicle frame to provide a complete path for electrical current. |
| group injection
| A method of injecting fuel into the manifold areas of several cylinders of an electronic fuel-injection system while at the same time, actually entering each cylinder as its intake valve is opened. |
| groupie
| One, especially a female, who follows the racing circuits hoping to be accepted by its members. |
| growler
| Electrical tester designed to test starter and DC generator armatures. |
| GST
| Generic scan tool |
| GT
| An acronym for gran turismo, Italian for "grand touring." |
| GTAC
| An acronym for gas-tungsten arc cutting. |
| GTAW
| An acronym for gas-tungsten arc welding. |
| GTO
| An acronym for gran turismo omologato. |
| GTW
| An acronym for gross trailer weight. |
| guard
| A barrier, such as a shroud, that physically prevents entry of the operator's hands or fingers into the point of operation. |
| Gudgeon pin
| English term for wrist pin |
| GUI
| An acronym for Graphical User Interface. A program interface that takes advantage of the computer's graphics capabilities to make the program easer to use such as Microsoft Windows |
| guide
| 1. A part used to align an assembly or another part. 2. The support for a valve stem in the head. |
| guide block
| A metal or hard-rubber device used to maintain timing-chain tension. |
| guide insert
| A valve-guide insert that is not an original part of the cylinder head; used to replace a worn integral valve guide. |
| guide liner
| A thin, bronze sleeve used to repair a worn-out valve guide. |
| guide plate
| A metal plate on the cylinder head that keeps the push rod aligned with the rocker arm. |
| guide rail
| A device that keeps the timing chain aligned and in the correct position. |
| guide seal
| A seal that prevents oil from being drawn into the valve guide. |
| guide shoe
| A device used to maintain tension on the timing chain of an overhead-cam engine. |
| guide sleeve
| A tubular sleeve that is placed on a connecting rod bolt when it is removed, to prevent the bolt threads from scratching the crank pin. |
| Guide-Matic
| An electronic headlamp control that automatically shifts between upper and lower beams as required. |
| guide-mounted seal
| A seal that mounts directly onto the valve guide. |
| gullwing
| A coupe-body style with the doors hinged so they open upward. |
| gulp valve
| A valve that opens in an air-injection system to admit extra air into the intake manifold upon deceleration, thus "leaning out" the mixture to prevent backfiring. |
| gum
| Residue that remains when gasoline is allowed to sit for a period of time. |
| gumballs
| 1. Drag racing tires made of especially soft, sticky compound. 2. The rotating light in a hemispherical housing on top of a police car or emergency vehicle. |
| gun it
| To rev up an engine suddenly. |
| gun-drilled oil holes
| Holes that are drilled to allow oil to be fed to the piston pin. |
| gurgle method
| A method of adding refrigerant from small cans to a system without running the engine. |
| gusset
| A triangular piece of metal used to add strength to a corner. |
| gut
| To remove non-functional parts of a vehicle in order to reduce its weight. |
| guts
| 1. The internal structure of a vehicle. 2. The essential working parts of a device. |
| GVW
| Gross vehicle weight |
| GVWR
| An acronym for gross vehicle-weight rating. Total weight of a vehicle plus its maximum rated payload. |
| gymkhana
| An individually clocked maneuverability contest for sports cars over an extremely tight course. |
Auto & Car Glossary
