| D
| An acronym for drive; one of the forward gear positions in an automatic transmission. |
| D-1
| The low forward-drive range of an automatic transmission. |
| D-2
| The high, forward-driving range for an automatic transmission. |
| D-cam
| The pattern used for grinding pistons in a cam shape with a 0.012 inch (0.3mm) difference between the thrust face and the pinhole side. |
| D-Jetronic
| An early fuel-injection system by Bosch. |
| D-port
| An intake or exhaust port shaped like the letter D. |
| D-ring
| A control in a drag-racing car's cockpit used to deploy the chute at the end of the run. |
| DAC
| An acronym for digital to analog converter. |
| dago axle
| a dropped-beam axle used on older Fords to dump or lower the front end. |
| dam
| the sealing provisions located between the radiator and condenser to ensure adequate ambient and ram air through both components. |
| damage appraiser
| A term often used for estimator. |
| dampened pressure switch
| An electrical pressure switch that opens the compressor clutch circuit when the low-side pressure is too low. |
| dampener
| A term often used incorrectly for damper. |
| dampening ball joint
| A term used for non-load-bearing ball joint. |
| dampening effect
| The effect shocks have on reducing suspension-spring oscillations. |
| Damper
| [1] English term for Shock Absorber [2] Friction or hydraulic shock absorbers or the equivalent electronic device [2] a device that reduces or eliminates vibration or oscellations [3] a balancer on the front of the crank shaft to reduce or eliminate harmonic vibrations |
| damper assembly
| A device designed to decrease vibrations to the passenger compartment. |
| DAQ
| Utah's Division of Air Quality |
| dark current
| A small leakage current that flows through a photosensitive device in the absence of light. |
| Darlington pair
| Two transistors electrically connected to form an amplifier permitting a small amount of current flow to control a larger current flow ( an electronic relay). Named for Sidney Darlington, a physicist at Bell Laboratories from 1929 to 1971. |
| dArsonval
| Jaques-Arsene dArsonval French physiologist ( 1851 - 1940 ) The enventor of the Deprez - dArsonval galvanometer a highly sencative volt meter |
| dash
| 1. A short term for dashboard. 2. A short race, usually about six laps. |
| dash components
| Accessories, such as the air conditioner and/or heater, that are mounted on the firewall in the engine compartment. |
| dash control valve
| Hand-operated valves located on the dash, such as parking-brake valves, tractor-protection valves, and differential locks. |
| Dash series
| A NASCAR race series for four-cylinder, subcompact cars. |
| dashboard
| The section immediately behind the windshield that houses the instruments, accessory controls, and glove box. |
| dashpot
| A device found on the carburetor that prevents a fast-closing throttle action. |
| Dashpot timer
| A device using a piston moving through a liquid to produce a time delay |
| data
| Information specifically in digital format that is operated on by the micro possessor and produces an output. |
| data base
| Any collection of data organized for accessing and retrieving |
| Data Bus
| A collection of wires through which data is transmitted from one part of the computer to another or from one computer to another. |
| Data Line
| A scan tool transmission line designed to read sensor values and fault codes read from the RAM memory not directly from the circuit |
| data link
| A device in a computer system that sends and receives digital signals. |
| data link connector (DCL)
| The vehicle connector that allows the scanner to interface with the vehicles PCM. In OBD-II vehicles the DLC must be located on the left hand side of the passenger compartment in view of the service technician. |
| data processing
| The handling of information in a series of prescribed operations such as adding, moving, perform logic, input, output, read, write, etc, to achieve a desired result. |
| data processor
| A device that is capable of performing data operations, such as a microcomputer. |
| datum point
| The starting point for measuring an object. |
| daylight
| To be ahead of a competitor by more than a car length in side-by-side racing, so daylight is visible between the two vehicles. |
| Daytona
| The Daytona International Speedway. |
| Daytona International Speedway
| A speedway in Daytona Beach, Florida. Home of the Daytona 500, Firecracker 400, and IMSA"s 24-hour sport-car endurance race. |
| dB
| Decibel |
| DBC
| an acronym for dual-bed catalytic. |
| DC
| An acronym for direct current. |
| DC Coupling
| An oscilloscope setting that allows the scope to display both AC and DC Signals |
| DCL
| Data communications link |
| DCS
| Deceleration control system |
| DCTO
| Dual coolant temperature override |
| DDA
| Detroit Diesel Allison |
| DDC
| Diesel Data Center |
| DDD
| Dual diaphragm distributor |
| DDE
| European Digital Diesel Electronics |
| de Dion axle
| A drive system with a differential or transaxle attached to the frame and exposed, universal-jointed half-shafts driving the wheels with a separate dead axle connecting the wheels that holds them upright and supports the springs. |
| De energized
| Having the electric current or energy source turned off |
| de-ice switch
| A switch used to control compressor operation to prevent evaporator freeze-up. |
| DE-MOSFET
| (depletion-enhancement metal oxide semiconductor field effect transistor) This transistor can be operated in either a depletion or enhancement mode. |
| Deactivate
| A series of seps necessary to turn a feature or function off |
| dead axle
| A shaft, such as the rear axle on a front-wheel drive vehicle, that connects wheels to either side of a vehicle but does not provide driving power. |
| Dead center
| The extreme top or bottom of the pistion stroke |
| dead player
| A vehicle part or assembly that is inoperable. |
| Dead Short
| A zero resistance short circuit |
| dead spot
| The momentary loss of power in an engine while increasing its speed. |
| dealership
| A privately owned sales and service facility representing an automobile manufacturer. |
| deburr
| To remove sharp edges from a part. |
| DEC
| Diesel electronic control |
| decarbonize
| To remove carbon deposits. Also known as decarburize. |
| decarburize
| Same as decarbonize. |
| decel valve
| A device that reduces exhaust emissions during vehicle deceleration by keeping rpm up and vacuum down. |
| decelerate
| To decrease speed. |
| deceleration
| 1. A decrease in velocity or speed. 2. To allow the vehicle to coast to idle speed from a high speed. |
| deceleration valve
| A device used withy the dual-diaphragm, vacuum-advance to advance engine timing under deceleration conditions. |
| dechrome
| 1. To strip the vehicle of chrome for modification. 2. To remove the chrome prior to body repair and/or painting. |
| deci
| The prefix representing the number 0.1 |
| decibel (dB)
| A standard of measure for the relative loudness of a sound. |
| deck
| 1. The flat, mating surfaces of an engine block and head. 2. The trunk of a passenger car. 3. To machine an engine block deck flat. 4. To dechrome the deck lid. |
| deck lid
| The trunk door, or cover. |
| deck plate
| A heavy metal plate that is bolted to an engine block during cylinder-honing operations. |
| declutching fan
| An engine-cooling fan system, mounted on the water pump, having a temperature-sensitive device that governs or limits terminal speed. |
| decoke
| A British term for decarbonize. |
| deep cycling
| A condition where a battery is completely discharged before it is recharged. |
| deep staging
| A drag-racing technique where the driver uses minimum roll out to avoid breakout. |
| deep sump
| An oil pan, used on some drag-race cars, that is deep enough to keep the oil away from the crankshaft at high rpm to slightly increase horsepower. |
| deep-dish wheel
| A wheel with an extremely positive offset. |
| deep-rolled fillets
| The transition radius between a journal and the cheeks of a crankshaft. |
| default
| A value or setting that a device or program automatically selects if you do not specify a subroutine |
| default setup
| The setup that exists as long as there are no changes made to the settings. |
| DEFI
| Digital electronic fuel injection |
| deflection
| 1.An axial or radial movement away from the normal or standard axis of a part. 2. A bending or distorting motion; usually applied to a brake drum when it is forced out-of-round during brake application. |
| deflection angle
| The angle at which oil is deflected inside a torque converter during operation; the greater the angle, the greater the torque applied to the output shaft. |
| deflection rate
| The number of pounds required to compress a spring one inch (25.4 mm). |
| defogger
| That part of the heater system designed to clear the windshield of fog haze under certain conditions. |
| defrost door
| A small door within the duct system that diverts a portion of the delivery air to the windshield. |
| defrost switch
| A thermostatic-type switch that senses evaporator temperature and turns the compressor off to prevent frosting or ice formation on the evaporator. |
| defroster
| That part of the heater system designed to clear heavy frost or light ice from the inside or outside of the windshield. |
| defroster door
| A term often used for defrost door. |
| deg
| An acronym for degree. |
| degreaser
| A chemical that breaks oil and grease down. |
| degreasing
| Cleaning parts in a solvent to remove oil and grease. |
| degree
| Part of a circle; one degree is 1/360th of a circle. |
| degreeing a cam
| Using instruments to determine the actual timing of valves opening and closing for a particular camshaft. |
| dehumidify
| To remove water vapor from the air. |
| dehydrate
| A process for dehumidifying. |
| dehydrator
| 1. A machine used to dehydrate a system or component. 2. A term often used for drier. |
| dehydrator filter
| A term used for filter drier. |
| deka
| The prefix representing the number 10 |
| Delayed Time Base
| A time base with a sweep that can start (or be triggered to start) relative to a pre-determined time on the main time bade sweep. Allows the user to see events more clearly and to see events that are not visible solely with the main time base sweep |
| Delco Eye
| A type of built-in battery tester that provides an immediate visual indication of battery conditions. |
| delta "p"
| A term used when referring to a difference in pressure. |
| delta "t"
| A term used when referring to a difference in temperature. |
| delta connection
| The interconnection of three windings, such as an alternator stator in a triangular fashion. Named for the triangle shaped Greek capital letter delta, also knowen as a delta winding. |
| Delta time
| The chang in time when chosen from the cursor menu displays the amount of time displayed between the cursors |
| DEMA
| An acronym for Diesel Engine Manufacturers Association. |
| demagnetization
| The process of removing magnetism from a magnetized substance. |
| demagnetize
| To reduce or remove the magnetism from an object. |
| denatured alcohol
| Ethyl alcohol, used to clean brake systems; contains methanol, rendering it unfit for human consumption. |
| Department of Environmental Regulation (DER)
| A department of the United States Environmental Protection Agency (EPA). |
| Department of Transportation (DOT)
| The United States Department of Transportation, a federal agency charged with the regulation and control of the shipment of all hazardous materials. |
| departure angle
| The maximum angle, in degrees, of a line running rearward and upward from the rear tire contact point to the lowest obstruction under the rear of the vehicle. |
| depolarize
| To remove or eliminate positive and negative poles from an item. |
| deposited metal
| Any filler metal that may have been added during a welding process. |
| depressed park
| The out-of-sight positioning, below the hood line, of windshield wiper blades of some wiper systems. |
| depressurize
| To release or remove pressure. |
| depth filter
| A filter that traps contaminants within the matrix of the filter material. A felt filter is a type of depth filter. |
| depth of fusion
| The penetration that a weld fusion extends into the base metal, or previous bead, from the surface. |
| DEQ
| The Utah Departmant of Enviornmental Quality |
| DER
| An acronym for Department of Environmental Regulations. |
| DERM
| Diagnostic energy reserve module |
| desiccant
| 1. A material, such as silica gel, that absorbs moisture from a gas or liquid. 2. A drying agent used in refrigeration systems to remove excess moisture. |
| design working pressure
| The maximum pressure under which a specific system or component is designed to work safely and without failing. |
| desmodromic valves
| A valve system in which positive cam action, not spring action, is used to open and close the intake and exhaust valves. |
| detent
| 1. A recess to hold the gear selector in the gear range selected. 2. A pin, stud, or lever which initiates or halts an action at a determined time or interval. 3. A valve that controls downshifting by boosting throttle pressure. |
| detergent
| 1.A chemical, added to engine oil, that possesses the ability to clean by preventing the accumulation of deposits. 2. An additive used in gasoline to prevent and/or clean up fuel system deposits. |
| detergent dispersant
| A chemical component in motor oil that loosens dirt and varnish in an engine. |
| detergent oil
| An oil with a detergent additive. |
| detonation
| A phenomenon of internal combustion where the compressed air/fuel charge explodes violently instead of burning smoothly, usually due to the creation of a second flame front in the combustion chamber, away from the spark plug. Sometimes resulting in an audible knocking noise but always harmful to the engine. |
| detonation sensor
| A device, mounted on an engine block, cylinder head, or intake manifold, that generates and sends a small voltage signal to the ECU, to retard timing, when encountering the vibration frequency associated with detonation. |
| detonation-detection sensor
| A term often used for detonation sensor. |
| Detroit locker
| A specific brand of locking rear-end differential. |
| deuce
| 1. A 1932 Ford. 2. A two-barrel carburetor. 3. A 1962 through 1967 Chevrolet. |
| deuce and a half
| A truck having a nominal payload capacity of 2-1/2 tons. |
| deuce and a quarter
| The Buick Electra 225, particularly the 225-inch-long 1959 model. |
| Dex-Cool
| A ling-life antifreeze manufactured by Texaco, Used in most GM heavy and light duty vehicles, Dex-cool is an ethylene glycol based antifreeze that contains (OAT's ((Organic Acid Technology)) rather than nitrates and phosphates or silicates as corrosion inhibiting chemicals) Normilly dyed Orange to distinguish it from other Ethylene glycol antifreezes and Propylene glycol. |
| Dexcool
| See Dex-Cool |
| Dexron II
| A petroleum-based automatic transmission fluid developed by General Motors. |
| DFC
| Deceleration fuel control |
| DFI
| Digital fuel injection |
| DFRDTE
| (Porsch) Oxygen sensor Difference |
| DFS
| Dual function switch or deceleration fuel shutoff |
| DG
| An acronym for double-groove valve tem. |
| DI
| Distributor ignition or direct ignition |
| dia
| An acronym for diameter. |
| Diac
| A bidirectritional diode |
| diagnose
| To recognize by signs and symptoms |
| diagnosis
| 1. A standard procedure that is followed to locate and identify the cause of a malfunction. 2. The art ro act of identifying the cause of a problem or malfunction by observing its signs and symptoms. |
| diagnostic
| Any number of on-board tests run by the diagnostic management system which checks for malfunctions, errors or breakdowns in vehicle systems or components. |
| Diagnostic Code
| a set of Numbers obtained from a Computer either by the use of flasching "Check Engine" lights or with the use of a scantool |
| diagnostic executive
| The diagnostic management system software that stores testing results and controls the illumination of the malfunction indicator lamp |
| diagnostic management system
| The PCM system responsible for preforming testing of the powertrain components and systems, recording testing results and preforming test fail actions. |
| Diagnostic Mode
| This Chrysler mode of operation is used by the Ligic Module to indicate malfunctions to the technician through Flash codes |
| Diagnostic Read Out BOX
| Chryslers Scan tool now up to DBR IV |
| Diagnostic Trouble Code
| A number generated by the vehicles computer to indicate a flaiure in a sensor, circuit, or the computer itself |
| Diagnostic Trouble Codes
| Any code stored in a control module memory used to aid the technician in the diagnosis of a system |
| diagnostician
| A person who determines the cause of problems when given all the signs and symptoms. |
| diagonal brake system
| A dual-brake system with separate hydraulic circuits connecting diagonal wheels together; right front to left rear and left front to right rear. |
| diagonal cross check
| In preparation for oval-track racing, the measure of weight distribution between the right-front and left-rear wheels and between the left-front and right-rear wheels. |
| dial
| An instrument with an analog-gauge indicator. |
| dial in
| 1. To set the Christmas tree for drag racing events, with the interval between starting times for vehicles with different indexes. 2. To set up a car with the right combination for maximum performance for any particular racing condition. |
| dial under
| A practice allowed under NASCAR rules in handicap eliminations for Stock and Super Stock classes where the breakout rule is in effect. |
| diameter
| The cross-section measurement of a round or circular object. |
| diaphragm
| 1. A flexible membrane in a speaker or microphone where electrical signals are converted to sound vibrations and vice versa. 2. The flexible membrane found in a temperature- or pressure-control device that seals in an inert fluid from the atmosphere while allowing a mechanical movement. |
| diaphragm clutch
| A clutch having a shallow, cone-shaped spring disc to provide pressure to the plate. |
| diaphragm spring
| 1. A spring shaped like a disk with taped fingers pointed inward. 2. A spring shaped like a wavy disk. |
| diaphragm-spring clutch
| A clutch in which a diaphragm spring applies pressure against the friction disk. |
| Diatomacoeus Earth
| (Kitty Litter) An absorbent material containing an abundance of diatoms or their siliceous remains. |
| DIC
| Driver Information Center |
| dice
| A tight contest between two cars on an oval track or road course generally battling for a specific position. |
| dichlorodifluoromethane
| the proper chemical name for Refrigerant-12. |
| die out
| To stall or stop running. |
| dielectric
| 1. An insulator. 2. A term referring to the insulation between the plates of a capacitor. |
| dielectric grease
| Lithium or silicone based grease used to lubricate, protect from moisture, and dissipate heat while acting as a non-conductor; applications include light bulb sockets, spark plug boots, distributor caps and under ignition modules |
| dielectric strength
| The ability of an insulator to insulate; to resist carrying current without damage. 2. The resistance to electron penetration. |
| diesel cycle
| An engine operating cycle where the air is compressed and the fuel is injected at the end of the compression stroke, causing ignition. |
| diesel engine
| A compression-ignition engine. |
| Diesel Engine Manufacturers Association (DEMA)
| A professional association of diesel-engine manufacturers. |
| dieseling
| A condition in which a carbureted engine continues to run after the ignition is shut off. |
| diff
| An acronym for differential. |
| differential
| The section of the rear-axle assembly that provides three functions: it allows the wheels to revolve at different speeds during turns, provides the final gear reduction and changes the angle of drive 90 degrees. |
| differential action
| An operational situation where one driving wheel can rotate at a slower speed than the opposite driving wheel. |
| differential assembly
| The mechanism that relates to front- or rear -driving axles that permits unequal travel distances and speeds between the vehicle's driving wheels. |
| differential case
| The housing of the differential that contains the side and pinion gears and the pinion shaft, and also serves as a mounting place for the ring gear. |
| differential drive gear
| A large, circular helical gear that is driven by the transaxle pinion gear and shaft and that drives the differential assembly. |
| differential housing
| Also known as rear-axle housing. A cast iron assembly that houses the differential unit and the drive axles. |
| differential lock
| A toggle or push-pull type air switch that locks together the rear axles of a tractor so they pull as one for off-the-road operation. |
| differential pinion gears
| Small, beveled gears located on the differential pinion shaft. |
| differential pinion shaft
| A short shaft locked to the differential case. This shaft supports the differential pinion gears. |
| differential pressure valve
| A device that maintains a constant pressure to fuel injectors. |
| differential side gear
| The gears that are internally splined to the axle shafts, which are driven by the pinion gears. |
| dig out
| To accelerate suddenly, as in the start of a race. |
| digger
| A dragster. |
| digital
| 1. Relating to the technology of computers and data communications where all information is encoded as bits of 1's or 0's that represent ON or OFF states. 2. A numerical readout. |
| digital computer
| A device that manipulates digital data and performs arithmetic and logic operations on such data. |
| Digital device
| A device that has only two states of operation, on and off |
| digital electronic fuel injection
| An early Cadillac electronic fuel-injection system. |
| digital instrument
| A display that indicates an activity, such as rpm, mph, voltage, or fuel supply, with an electronic readout; used in most Indy cars, though some drivers still prefer analog instruments. |
| Digital Logic
| Circuit elements connected in such a manner as to solve problems using components that have only two states of operation |
| digital oscilloscope
| A type of oscilloscope that uses an analog-todigital converter to convert the measured voltage into digital information. Three types of Digital Oscilloscopes are digital storage, digital phosphor, and digital sampling oscilloscopes |
| Digital Phosphor Oscilloscope
| A type of digital oscilloscope that closely modles the display characteristrics of an analog scope while providing traditional digital scope benefits. |
| digital read out (DRO)
| A method of electronically reading conditions as opposed to an analog readout. |
| Digital Sampling Oscilloscope
| A type of digital ooscilloscope that employs equivalent-time sampling method to capture and display samples of a signal, ideal for accurately capturing signals whose frequency components are much higher than the oscilloscopes sample rate |
| digital signal
| A signal whose level has only discreet values, like on or off, 1 or 0, +5v or +0.2 v. |
| digital speech
| Recorded speech broken into tiny units of sound, each having characteristics such as pitch and loudness that can be represented by numbers, becoming the digital code for speech. |
| Digital Storage Oscilloscope
| A digital oscilloscope that acquires signals via digital sampling (using an analog-to-digital converter) It uses a serial-processing architecture to control acquistion, user interface, and the raster display |
| digital-to-analog converter
| A device, generally electronic, used to convert discrete digital numbers to continuous analog signals. |
| Digitize
| The process by which an analog-todigital converter in the horizontal system samples a signal at discrete points in time and converts the signal's voltage at these points into digital values called sample points |
| digitized
| The process of converting an analog voltage signal to a digital equivalent that the computer can understand. |
| digs
| The drag races. |
| diluent
| A liquid that extends a solution but definitely acts to weaken the solvent power of the active solution. |
| dilution
| To make thinner or weaker. Oil is diluted by the unintentional addition of fuel and water droplets. |
| dimmer switch
| A switch that allows the driver to select either high- or low-beam operation of the headlights, and to switch between the two. |
| dimple
| The process of turning a hole under or down to allow the installation of a fastener. |
| dimpling
| the distortion of an oil-pan rail around the bolt hole. |
| ding
| A small dent. |
| diode
| An electrical one-way check valve made by joining P-material to N-material at a junction |
| diode trio
| A group of three diodes grouped together with one output used to provide rectified current to the field and voltage regulator on many internally regulated alternators |
| diolefins
| An ingredient of gasoline which contribute to gum and lacquer formation in the fuel system. |
| DIP
| Dual inline package |
| dip stick
| A thin, steel strip of metal used to measure the fluid level or quantity in the engine, transmission, or compressor. |
| dipper
| A small, metal scoop at the bottom of a connecting rod to scoop up oil from the pan to lubricate the bearing. |
| dipper trough
| A trough aligned under the connecting rod that is fitted with the dipper. |
| direct battery power
| Power available to a circuit in the automobile directly from the battery, without an intermediate switch. |
| direct current (DC)
| 1.Current flow in one direction only such as the current produced by a battery. |
| direct drive
| A transmission mode in which the driveshaft and engine crankshaft are at the same speed. |
| Direct Fuel Cell
| A type of fuel cell in which a hydrocarbon fuel is fed directly to the fuel cell stack without requring an external "reformer" to generate hydrogen. |
| direct ignition system
| An ignition system where impulses are sent directly to the spark plugs by a modulator. |
| direct injection
| A type of fuel-injection system that injects fuel directly into the cylinders. |
| direct-acting shock absorber
| A double-action design controlling up and down suspension travel; it is mounted directly between the frame of the vehicle and the control arm or axle. |
| direct-acting thermostatic air cleaner
| A component of heated air-intake systems that uses a thermostatic bulb connected to a rod to operate a flapper valve in the air-cleaner snorkel. |
| direct-bonded bearing
| A bearing that is formed by pouring molten babbitt directly into the bearing housing and machining the cooled metal to the desired diameter. |
| direct-clutch solenoid
| A solenoid that directs fluid flow to engage the direct clutch. |
| directional control
| The ability to steer the automobile while stopping |
| directional signals
| Lights at either side of both the front and rear of the vehicle that flash to indicate an intended turn. |
| directional stability
| The ability to maintain a straight line wile stopping |
| directional tire
| A tire having a tread pattern that must be mounted facing forward. |
| dirt dobber
| A circle-track race driver that prefers a dirt track over an asphalt track. |
| dirt tracking
| Driving on an asphalt track as if it were a dirt track. |
| DIS
| Direct ignition system or distributorless ignition system |
| DISA
| Differential air intake control system |
| disable
| 1. To remove or inhibit normal capability. 2. A command that prevents further operation of a peripheral device. |
| disassemble
| To take apart. |
| disc
| 1. An acronym for discount. 2. A variant of disk. |
| disc brake
| A type of brake that provides a means of slowing or stopping a vehicle using hydraulic pressure to apply pads against a rotor. |
| disc minimum thickness
| The least thickness, usually stamped or cast into the disc, to which a brake disc can be machined or worn before it becomes unsafe. |
| disc-brake fluid
| A special fluid having a high boiling point, about 500 degrees F (260 degrees C). If exposed to air, it will attract moisture and be unsafe for use. |
| disc-brake pad
| An assembly consisting of friction material and its steel backing. |
| discharge
| 1. Releasing some, or all, refrigerant from a system by opening a valve to permit the refrigerant to escape slowly into a recovery system. 2. To purge air from a sealed system. |
| discharge air
| Conditioned air as it passes through the outlets and enters the passenger compartment. |
| discharge line
| The fluid line that connects the compressor outlet to the condenser inlet. |
| discharge pressure
| The high-side pressure of the refrigerant as it is being discharged from the compressor. Also known as high-side pressure. |
| discharge pressure switch
| A term used for compressor-discharge pressure switch. |
| discharge side
| That portion of the refrigeration system under high pressure, extending from the compressor outlet to the metering-device inlet. |
| discharge valve
| A term used for high-side service valve. |
| disconnect
| A switching device for disconnecting an electrical circuit or load from the power supply. |
| discrete components
| An electrical component, such as a capacitor, that has been fabricated prior to its installation. |
| discrete device
| An individual electrical component, such as a resistor. |
| Discriminating Sensors
| Parts of the air bag circuitry that calibrate to close with speed changes that are great enough to warrant air bag deployment |
| disengage
| To disconnect; used to describe the action when a clutch uncouples the power of the driving part from the driven part. |
| dished piston
| A piston having a depression in the crown. |
| disk
| 1. A magnetic device for storing information and programs accessible by a computer. 2. The rotor, a revolving piece of metal, against which shoes are applied to provide a braking action. 3. A two-dimensional figure defined by all points enclosed by a circle's diameter. 4 Often referred to as disc. |
| disk drive
| A device that stores, reads, or retrieves data from a magnetic disk and copies it into the computer's memory for use. |
| disk runout
| The amount that a brake disk wobbles during rotation. |
| disk-operating system
| An operating system in which the programs are stored on magnetic disks that keep track of, save, and retrieve files; allocate storage space and manage other control functions. |
| disperesant
| A chemical added to oil that prevents impurities from clinging together and forming lumps that could clog the lubrication system galleys. |
| displacement
| The volume within an engine's cylinders, usually expressed in cubic centimeters (cc). |
| displacement current
| An expression for the effective current flow across a capacitor. |
| display terminal
| An output device, such as a CRT, that produces a visual representation of graphic data. |
| disposable cylinder
| A mainarea for the one-time use of packaging, transporting, and dispensing of a fluid, such as refrigerant. It is a violation of Federal Law to refill these cylinders, commonly referred to as "DOT-39s." |
| disposal
| To get rid of something |
| disqualified
| 1. To render unfit. 2. To be deprived of a right or privilege. |
| dist
| An acronym for distributor. |
| distance learning
| A type of education in which students work on their own at home or at the office and communicate with faculty and other students via e-mail, electronic forums, videoconferencing, and other forms of computer-based communication. |
| distillation
| The process that consists of driving gas or vapor from liquids or solids by heating and condensing . Used for purification, fractionation, or the formation of new substances. |
| distillation curve
| The reference to plotting a line connecting the percentages of gasoline that evaporate at various temperatures. The distillation curve is used as an important control for fuel standards such as volatility (vaporization). |
| distillation endpoint
| The temperature at which a fuel is completely vaporized. |
| distortion
| 1. Inaccuracies in size and shape, as in an out-of-round cylinder. 2. An unwanted change in purity of sound, as caused by a weak signal. 3. A term used for tread distortion. |
| distributor
| 1. A jobber; one who buys from a manufacturer and sells to a wholesaler. 2. A device used to direct electrical current to spark plugs. 3. A device used to direct fuel to injectors. |
| distributor advance
| A term used for centrifugal advance, ignition advance, or vacuum advance. |
| distributor cam
| The four-, six-, or eight-sided lobe at the top end of the distributor shaft that rotates to cause the contact points to open and close. |
| distributor cap
| A cover for the conventional ignition-system distributor, having a central terminal that receives secondary voltage from the coil and four, six, or eight peripheral terminals to send this voltage to the spark plugs. |
| distributor housing
| A metal part that contains or provides a mounting for distributor components in a conventional ignition system. |
| distributor ignition
| An ignition system that relies on a conventional distributor for proper operation. |
| distributor pipe
| A pipe to convey fuel from the fuel distributor to the injector. |
| distributor plate
| The plate inside a distributor that is fastened to the housing and does not move. |
| distributor rail
| A term used for distributor pipe. |
| distributor timing
| A term used for ignition timing. |
| distributor vacuum advance
| A term used for vacuum advance. |
| distributor vacuum-advance control valve
| A term often used for deceleration valve. |
| distributorless ignition
| A term used for distributorless ignition system. |
| distributorless ignition system
| An ignition system that relies on a computer to distribute the electrical spark to the proper spark plug. |
| div
| An acronym for division. |
| dive
| The tendency of the front of a vehicle to press down on the front springs during heavy braking. |
| divergent nozzle end
| An exhaust-pipe nozzle end that expands from the inlet to the end. |
| divergent-convergent nozzle end
| An exhaust-pipe nozzle that is expanded then reduced in size at the end. |
| diverter valve
| A vacuum-operated valve in an air-injection system that directs air-pump output to the atmosphere during high-vacuum deceleration to eliminate backfiring. |
| division
| 1. A branch or department of an organization. 2. The mathematic operation to determine how many of one number is contained in another; for example, how many 10s are in 100. |
| DIY
| An acronym for do-it-yourself. |
| DIYer
| An acronym for a do-it-yourselfer. |
| dizzy
| Slang for distributor. |
| DKV
| Deceleration kick valve |
| DLC
| an acronym for Data Link Connector formerly referred to as the ALDL or assembly line communications link, this is the connector to which the diagnostic scan tools are connected, |
| DM
| A Mercedes acronym for Diagnostic Module-Emission Monitor |
| DMCV
| Deceleration mixture control valve |
| DME
| Digital motor electronics |
| DMIVA
| Distributor mounted ignition module with vacuum advance |
| DMM
| Digital multi-meter |
| DMS
| Dual manifold system |
| DMV
| Department of Motor Vehicles or distributor modulator valve |
| DNF
| An acronym for "did not finish". |
| do-it-yourself (DIY)
| To repair one's vehicle. |
| do-it-yourselfer (DIYer)
| One known to repair their own vehicles. |
| Dobson unit (DU)
| A measure of ozone density level, named after Gordon Dobson, a British meteorologist, who was the indenter of the measuring device (called a spectrophotometer) |
| DOE
| Department of Energy |
| dog
| 1. A poor performing vehicle. 2. To follow another car very closely in oval-track racing. 3. A pin or stub used to mate and/or drive a gear or assembly. |
| dog clutch
| 1. A simple splined clutch that cannot be slipped; generally found in dirt-track cars without transmissions. 2. The mating collars, flanges, or lugs that can be moved as desired to engage or disengage similar collars, flanges, or lugs in order to transmit rotary motion. |
| dog house
| 1. The housing over an engine or transmission. 2. The front fenders, grille, and hod assembly of a vehicle. |
| dog leg
| A sharp, angular turn. |
| dog tracking
| Off-center tracking of rear wheels as related to the front wheels. |
| DOHC
| An acronym for dual overhead camshaft. |
| DOL
| Data output link |
| dolly
| To shape or form metal. |
| DOM tubing
| An acronym for drawn-over mandrel tubing with precise and consistent inside and outside dimensions, used for race-car chassis construction. |
| domed piston
| A piston having a raised crown. |
| Domestic
| Of U.S. manufacturer |
| donuts
| 1. A 360-degree tire burnout. 2. Tires, especially big racing slicks. |
| dooley
| A Chevrolet pick-up truck with dual rear wheels; generally a term given to any dual-wheel vehicle. |
| doorslammer
| A full-bodied drag car with functioning doors. |
| doosy
| A variation of doozie. |
| doozie
| 1. Short for Duesenberg, considered the greatest racing car ever built in the United States. 2. Anything, such as a car, that is truly fine or outstanding. |
| doped solder
| Solder containing a small amount of an added element to ensure retention of one or more characteristics of the materials on which it is used. |
| doping
| The intentional adding of impurities to pure silicon or germanium to form either P or N type semiconductor materials. |
| DOT
| An acronym for Department of Transportation. |
| DOT 3, 4, and 5
| U.S. Department of Transportation specification numbers for hydraulic brake fluids. |
| DOT 39
| Trade jargon for a disposable refrigerant cylinder. Disposable cylinders should never be refilled or used as compressed air tanks. |
| dot matrix
| A type of display or printer output in which each alphanumeric character is made up of an array of small dots. |
| double A-arm
| A suspension system using two A-arms or A-frames to connect the chassis to the wheel spindle. |
| double Cardian joint
| A near-constant-velocity universal joint consisting of two Cardian joints connected by a coupling yoke. |
| double century
| Two-hundred miles per hour. |
| double clutch
| A driving technique to minimize gear clash when shifting gears with a manual transmission. |
| double filament lamp
| A lamp designed for more than one function; used in the stoplight, tail light and the turn-signal circuits combined. |
| double flare
| A flare on the end of tubing, made by folding it over to form a double face. |
| double pivot control arm
| A term used for control arm. |
| double pole double throw (DPDT)
| A term used to identify a switch configuration having six terminals that connects one pair to either of the other two pairs of terminals. |
| double pole single throw (DPST)
| A term used to identify a switch configuration having four terminals that connect or disconnect two pairs of terminals simultaneously. |
| double ton
| Two-hundred miles per hour. |
| double wishbone
| A term used for double A-arm. |
| double wrap
| A flexible type of brake band designed with two segments that provide flexibility, which increases self-energizing action. |
| double-A frame
| A term used for double-A arm. |
| double-acting shock absorber
| A shock that provides a dampening effect on both compression and rebound. |
| double-groove valve stem
| A valve stem having two keeper grooves. |
| double-hump heads
| A term used for camel-hump heads. |
| double-J rim
| The double-J shaped safety locks on a rim, used to hold the inner and outer tire beads securely. |
| double-reduction differential
| A differential that contains extra gears to provide additional gear reduction. |
| DOV
| Dual orifice valve |
| dowel
| A pin inserted in an object or part to aid in the alignment of another object or part. |
| dowel pin
| A round, solid, or hollow pin used to align two or more parts. |
| downdraft carburetor
| A carburetor having a downward airflow. |
| downflow radiator
| A radiator in which the coolant flow is from the tip tank to the bottom tank. |
| downforce
| The downward force of air on a speeding vehicle. |
| downloading
| To copy data (usually an entire file) from a main source to a peripheral device. |
| downshift
| The automatic shift from a high gear ratio to a low gear ratio. |
| downshift valve
| An auxiliary shift valve that increases throttle pressure to force a downshift under high driveline loads, also called a kickdown or detent valve. |
| downstream blower
| A blower arranged in the duct system so as to pull air through the heater and/or air-conditioner core(s). |
| downtime
| 1. The time a system or machine is not available for use, due to failure or routine maintenance. 2. Time lost due to lack of service orders. |
| downward spring-and-wheel action
| A term used for rebound travel. |
| DP
| Dash pot |
| DPD
| Dual point distributor |
| DPDIS
| Dual plug distributorless ignition system |
| DPDT
| An acronym for double pole double throw. |
| DPFE
| A Ford term Differential pressure feedback EGR or Delta pressure feedback EGR |
| DPH
| Dual plug head |
| DPI
| Dual plug inhibit |
| DPS
| Differential pressure switch |
| DPST
| An acronym for double pole single throw. |
| DPVS
| Distributor ported vacuum switch |
| DQ
| An acronym for disqualified. |
| DQSDTE
| (Porsche) Air Quantity across the Idle air control valve (IACV) |
| DRAC
| an acronym for Digital Ration Adapter Controller, Used by the microprocessor to change analog signals to digital signals |
| draft
| To follow another vehicle close enough to take advantage of the slipstream or partial vacuum created behind it at very high speeds. |
| draft tube
| A vent to release engine-crankcase vapors. |
| drafting
| The technique of following another vehicle closely to save fuel. |
| drag
| 1. A performance term for a quarter-mile race from a standing start, against time or another car. 2. An acceleration contest between two vehicles. 3. The resistance of air against an object trying to pass through it. |
| drag coefficient
| A term used for coefficient of drag. |
| drag link
| The steering component that connects the Pitman arm to the steering arm. |
| drag racing
| An acceleration contest between two vehicles. |
| drag strip
| A standard racing strip 60 feet (18.3 meters) wide by 4,000 feet (1,219 meters) long, where eighth- or quarter-mile-competition events occur. |
| dragster
| A vehicle used for drag racing. |
| Drain
| The portion of a field effect transistor that receives the holes or electrons |
| Draw
| The amount of electrical current used by any load, circuit, or conductor |
| drawbar
| That part of a converter dolly that allows the fifth wheel to be repositioned on the frame. |
| drawbar capacity
| The maximum, horizontal pulling force that can be safely applied to a coupling device. |
| drawn-over mandrel tubing
| A type of seamless tubing with an accurate and precise inside and outside dimension; used in the construction of a race-car chassis. |
| DRB
| Diagnostic readout box |
| DRB-II
| Diagnostic readout box-stage II |
| DRB-III
| Diagnostic readout box-stage III |
| DRCV
| Distributor retard control valve |
| dressing
| A term used for belt dressing. |
| drier
| 1. A tubular device containing desiccant, usually placed in the liquid line to absorb moisture in an air-conditioning system. 2. A catalyst added to paint to speed the time required for curing. |
| drift
| A controlled slide through a turn involving all four wheels. |
| drift oil passage
| Holes drilled in various parts of the engine for pressurized oil to flow through. |
| drift pin
| A round, tapered, steel pin used to bring plates that are to be bolted or riveted into alignment to permit placing bolts or rivets easily. |
| drip pan
| A shallow pan under the evaporator core to catch the condensation that will be ejected by a drain hose fastened to the drip pan and extending to the outside. |
| drive axle
| An axle or axle shaft that transmits power to the drive wheels. |
| drive belt
| Flexible belt or belts used to connect a drive pulley on the crankshaft to the coolant pump and accessories. Two basic types of drive belts are the serpentine or multiple-ribbed belt and v-belt. |
| drive by wire
| To use an electronic throttle control rather than mechanical linkage. |
| drive coil
| A hollow field coil in a positive engaged starter that is used to attract the moveable pole shoe. |
| Drive Cycle
| The purpose of the OBDII drive cycle is to assure that all of the on-board diagnostic tests (monitors) have been run on the vehicle so that all of the I/M flags are set |
| drive fit
| A term used for interface fit. |
| drive gear
| In a combination of two operating gears, the first is the drive gear and the other is the driven gear. |
| drive line
| Assembly of various parts such as the driveshaft, universal joints, and connecting yokes that transmit torque from the transmission to the differential. |
| drive shaft
| An assembly of one or two universal joints connected to a shaft or tube used to transmit power from the transmission to the differential. |
| drive-line torque
| The transfer of torque between the transmission and the driving axle assembly. |
| driveability
| The general operation of a vehicle, rated from good to poor, based on the characteristics of the average driver. |
| driveline windup
| A reaction that takes place as a result of the transfer of engine torque through the rear-wheel driveline. |
| driven disk
| The friction disk of a clutch. |
| driven gear
| The gear that receives the driving action from the drive gear. |
| driven pinion
| A rotating shaft in the differential that transmits torque to another gear. |
| driven pinion gear
| One of the two main driving gears to multiply engine torque located within the transaxle or rear-driving axle housing. |
| driven plate
| The friction plate in a clutch assembly. |
| driver
| 1. The operator of a vehicle. 2. A car for everyday use.[3] An electronic switch (transistor) used to open and close the ground circuit of verious output devices. |
| driver-reaction distance
| The distance traveled between the point at which the driver perceives a need to brake and the actual start of brake application. |
| drivetrain
| All of the components required to deliver engine power to the road surface. |
| driving axle
| An axle capable of transmitting power by way of a differential or other transmission arrangement. Also a term used for drive axle. |
| driving lamps
| Auxiliary lights to provide additional illumination for high-speed driving. |
| driving lights
| A term used for driving lamps. |
| DRL
| Daytime running lights |
| drop
| To lower a structural part of a vehicle. |
| Drop head coup
| English term for Convertible |
| drop head coupe
| A British term for a two-door convertible. |
| drop the hammer
| 1. To engage the clutch and depress the accelerator suddenly. 2. To suddenly depress the accelerator to the floorboard. |
| drop through
| The undesirable sagging or surface irregularity encountered when brazing or welding; caused by overheating with rapid diffusion between the filler metal and the base metal. |
| drop-center rim
| A wheel that has a smaller diameter center section, to facilitate tire replacement, designed to prevent the tubeless tire from rolling off the rim when the tire blows out. |
| drop-center safety rim
| A wheel rim with a low center area and raised flanges designed to prevent the tire from accidentally coming off the rim. |
| drop-center wheel
| A conventional wheel that has a space in the center for one bead to fit into while the other bead is being lifted over the rim flange. |
| drop-throttle oversteer
| A term used for lift-throttle oversteer. |
| droplight
| An electrical light on a long extension cord. Also called a trouble light, or repair light. |
| dropped axle
| A lowered beam axle used on older Fords to dump the front end. |
| Dropping Resistor
| A resistor incerted in series with a line to reduce the voltage to a desired level |
| DRS
| Distance rpm sensor or distributor retard solenoid |
| druid
| A term used by a dissatisfied contestant, who has problems with the rules, when referring to a race official. |
| drum
| The part of a brake that rotates with the axle hub and that the brake shoes press against to slow or stop the vehicle. |
| drum armature
| A generator or motor armature having its coils wound longitudinally or parallel to its axis. |
| drum brake
| A type of brake in which stopping friction is created by shoes pressing against the inside of the rotating drum. |
| drum maximum diameter
| The largest diameter, generally 0.060 inch (1.5 mm) over originally to which a brake drum can be machined or worn before it is considered unsafe. |
| drum web
| The closed side of a brake drum. |
| drum-brake fade
| The loss of braking efficience due to excessive heat. |
| dry
| 1. The process of changing from a liquid to a solid, as in paint. 2. The process of evaporation, as in water. |
| dry deck
| A condition in which the piston crown is at the level of the block deck. |
| dry friction
| The friction between two dry solids. |
| dry fuel
| A fuel with an additive to prevent water from collecting and freezing in the fuel system. |
| dry gas
| Same as dry fuel. |
| dry-charged battery
| A battery that is filled with electrolyte only when put into service. |
| dry-disk clutch
| A clutch in which the friction faces of the friction disk are dry. |
| dry-film lubricant
| A petroleum-based chemical used to lubricate operating parts during assembly, prior to engine start up, to provide lubrication until oil is circulated after start up. |
| Dryer drive
| A type of starter-motor drive used in heavy-duty applications that provides mechanical meshing means and automatic demeshing. |
| drying agent
| A term used for desiccant. |
| DS
| Distance sensor or Dura-spark or deceleration solenoid |
| DS/CP/TVS
| Distributor spark/canister purge/thermal vacuum switch |
| DS/TVS
| Distributor spark/thermal vacuum switch |
| DS/TVV
| Distributor spark/thermal vacuum valve |
| DS/VDV
| Distributor spark/vacuum delay valve |
| DS/VMV
| Distributor spark/vacuum modulator valve |
| DS/VRDV
| Distributor spark/vacuum retard delay valve |
| DS/VRV
| Distributor spark/vacuum regulator valve |
| DSAS
| Deceleration spark advance system |
| DSDV
| Distributor spark delay valve |
| DSI
| Distributorless semiconductor ignition |
| DSO
| An acronym for Digital Storage Oscilloscope |
| DSR
| Ford Diagnostic Subrutine (KOEF or KOER) |
| DTC
| An acronym for diagnostic trouble code. It is also referred to as a fault code and is any code stored in the PCM memory. |
| DTCS
| Distributor thermal control switch |
| DTCV
| Distributor thermal control valve |
| DTM
| Diagnostic test mode, or Deceleration throttle modulator |
| DTVS
| [1] Delay thermal vacuum switch [2] Dual Temperature Vacuum Switch |
| DTVV
| Delay thermal vacuum valve |
| dual camshaft
| A type of engine that has two camshafts for opening and closing additional valves. |
| dual exhaust
| An exhaust system used on V-type engines with a separate muffler, exhaust, and tail pipe for each cylinder bank. |
| dual master cylinder
| A master cylinder, associated with a dual-brake system, having two sections for displacing fluid under pressure; generally one section for front brakes and one section for rear brakes or, in some applications, one for left brakes and the other for right brakes. |
| dual overhead camshaft
| Two cams in a single-cylinder head. |
| dual quads
| Two four-barrel carburetors. |
| Dual trace
| A feture that allows the oscilloscope to display two separate waveforms at the same time |
| dual-area diaphragm
| An automatic transmission shift control that receives its vacuum signal from the intake manifold and the EGR port. |
| dual-bed catalytic
| A term used for dual-bed catalytic converter. |
| dual-bed catalytic converter
| A catalytic converter that passes different gases through an upper or front chamber coated with platinum and rhodium and a lower or back chamber coated with platinum and palladium. |
| dual-bed converter
| A term used for dual-bed catalytic converter. |
| dual-brake system
| A brake system that uses two hydraulic circuits; should one fail, the other remains operational. |
| dual-diaphragm advance
| A vacuum-advance mechanism with two diaphragms; one for normal ignition timing and the other to retard the spark during idling and part-throttle operation. |
| dual-diaphragm distributor
| A distributor incorporating a dual-diaphragm advance. |
| dual-fuel engine
| 1. An engine designed to run on two separate fuels, such as gasoline or propane. 2. An engine designed to run on two fuels simultaneously, such as gasoline, alcohol, or a combination of the two. |
| dual-idler gear drive
| A timing-gear system having two idler gears for the crankshaft to drive the camshaft. |
| dual-ignition system
| An ignition system having two coils and two distributors, with two spark plugs for each cylinder. |
| dual-mass flywheel
| A flywheel that consists of two parts separated by springs used to absorb vibrations in the driveline |
| dual-plane crankshaft
| A crankshaft with two throws in two planes at right angles. |
| dual-plane manifold
| An intake manifold with two air cavities to provide air/fuel mixture to the cylinders. |
| dual-point system
| 1. An ignition system with two sets of points in the distributor. 2. A system that controls spark timing by electro-mechanical selection of separate advance and retard points. |
| duallie
| A Dodge pick-up truck with dual wheels; popular reference for any dual-wheel vehicle. |
| duals
| A term generally referring to two exhaust systems; two of anything, wheels, for example. |
| Dubble Start Override
| Prevents the starter motor from being energized if the engine is already running |
| ducktail
| An upswept rear end, often with a spoiler. |
| duct
| A tube or passage used to provide a means to transfer air or liquid from one point or place to another. |
| duct tape
| A heavy duty, fiber-backed tape used for emergency repairs to body parts, in all forms of racing. |
| ductility
| The property of a material that permits it to be worked by drawing or stretching without rupture. |
| duesie
| 1. Anything truly fine or outstanding. 2. Short for Duesenberg, touted by many to be the finest race car ever built. Also, doozie. |
| dummy
| A mannequin, such as used in crash tests. |
| dummy load
| An electrical test procedure to simulate actual operating conditions. |
| dummy shaft
| A shaft used as an aid in the assembly or disassembly of a parts group. |
| dump
| 1. To lower the front end. 2. To defeat a competitor in a drag race. 3. To damage or destroy a component, such as a transmission. |
| dump station
| A facility where RV's and others clean their holding tanks. |
| dump tubes
| Straight through exhaust headers. |
| dumped and tubbed
| A vehicle that has been lowered in the front and fitted with oversize wheel wells, |
| dune buggy
| A small, light-weight, off-road vehicle with little or no body work. |
| duo-servo
| A drum brake design with increased stopping power due to the servo or self-energizing effect of the brake. |
| duplex
| Simultaneous, independent, two-way transmission in both directions. |
| Dura Spark ignition
| An ignition system developed by Ford. |
| durability
| The quality of being useful, generally referring to the life of a catalyst or emission-control system. |
| duration
| 1.The time, in crankshaft degrees, that a camshaft holds an exhaust or intake valve open. 2. A rating system applied to engine camshafts that determines how long the valve will be open relative to crankshaft movement in degrees. |
| dust
| To overtake or defeat a competitor in a race. |
| dust off
| A term often used for dust. |
| dust shield
| 1. The upper portion of a shock absorber that surrounds the lower twin-tube unit. 2. A covering that protects an assembly from the elements. |
| dutched
| A paint job finished with elaborate striping or flame painting. |
| duty cycle
| 1. The percentage of time a component is on compared to the time the component is off during one cycle. 2.The percentage of time that a power source, or one of its accessories, can be operated at rated output, without overheating. |
| duty solenoid
| A solenoid on a feedback carburetor that cycles many times per second to control a metering rod, and therefore, the air/fuel mixture. |
| DV
| Diverter valve or delay valve |
| DV-TW
| Delay valve-two way |
| DV/TS
| Delay valve/trapped spark |
| DVA
| Distributor vacuum advance |
| DVAC
| Distributor vacuum advance control |
| DVAS
| Distributor vacuum advance solenoid |
| DVC
| Distributor vacuum control |
| DVCD
| Distributor vacuum delay valve |
| DVCS
| Distributor vacuum control solenoid |
| DVCV
| Distributor vacuum control valve |
| DVD
| An acronym for Digital Versatile Disc or Digital Video Disk; a new type of CD-ROM that holds a minimum of 4.7 GB, enough for a full-length movie. |
| DVMC
| Distributor vacuum modulator valve |
| DVOM
| Digital volt ohm meter |
| DVRS
| Distributor vacuum retard switch |
| DVRV
| Distributor vacuum regulating valve |
| DVSV
| Distributor vacuum solenoid valve |
| DVVV
| Distributor vacuum vent valve |
| dwell
| The length of time the distributor points are closed measured in degrees of distributor-shaft rotation. |
| dwell angle
| Another term used for dwell. |
| Dy
| Dysprosium An element with the atomic number of 66 |
| dye-penetrant testing
| A non-destructive, inexpensive method of testing metal for cracks. |
| Dykes ring
| A compression piston ring having an "L" cross-sectional shape that provides sealing against the cylinder walls. |
| dykum blue
| A blue dye used to color metal. |
| dynamic
| Pertaining to motion, force, energy or movement. |
| dynamic balance
| A term used when wheels are balanced using equipment that spins the tires and wheels as an assembly |
| dynamic data display
| The Mopar Diagnostic System software in which Input signals from various components plotted over time. |
| dynamic friction
| The coefficient of friction between two surfaces that have relative motion between them. Also knowen as kinetic friction. |
| dynamic range
| The operating range of a sensor. |
| dynamic seal
| A seal that prevents fluid passing between two parts that are in motion relative to each other. |
| dynamic voltage
| The voltage measured at the source with the circuit in operation. |
| dynamically balanced
| 1. A term that often refers to a wheel and tire being balanced while spinning. 2. In general terms, the balance of any object when it is in motion. |
| Dynamis Response Test
| A Ford term for a key on/engine running test in which a rapis acceleration is applied to the engine and the engine is checked for appropriate throttle movement, change in RPM, and change in the intake airflow. |
| dynamo
| An electric DC-current generator. |
| dynamometer
| A machine on which a vehicle may be driven, simulating actual driving conditions for emissions and diagnostic purposes. |
| dyno
| Short for dynamometer. |
| Dytel
| A trade name for a red dye found in some CFC refrigerants. |
| Dzus fastener
| A screw-like fastener that may be removed or installed with a quarter turn, ideal for race-car body panels that may have to be replaced quickly. |
Auto & Car Glossary...
Auto & Car Glossary
