- Lead
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- [pronounced LEED] A short connecting wire which makes electrical contact between two points.
- [pronounced LEED] The distance from the thread crest of a bolt or screw to the adjacent crest of the same thread, i.e., the distance a screw thread advances in one full turn.
- [pronounced LED] A metal that is soft, toxic, heavy, malleable, and ductile. Used in storage batteries, and as an anti-knock agent added to Gasoline in the form of Tetraethyl lead.
- Lead-acid battery
- An electricity producing system of lead plates and dilute sulfuric acid; used as a starter battery and as a traction battery in electric vehicles or as a source for lights because they are rechargeable, inexpensive, and durable
- Lead acid rechargeable battery
- Used in many light systems. Benefits include low cost and solid long term durability.
- Lead and lag
- The time between a valve opening and TDC or BDC (Valve lead), and the time between TDC or BDC and a valve closing (Valve lag); (compare Valve overlap)
- Lead dioxide
- A combination of lead and oxygen, as found in the storage battery. Lead dioxide is reddish brown in color
- Leaded gasoline
- Gasoline to which lead has been added as an anti-knock agent. Contains more than 0.05 grams of lead per US gallon or more than 0.005 grams of phosphorus per US gallon. The actual lead content of any given gallon may vary. Premium and regular grades are included, depending on the octane rating. Includes leaded Gasohol. Blendstock is excluded until blending has been completed. Alcohol that is to be used in the blending of gasohol is also excluded.
- Leaded petrol
- British term for Leaded gasoline
- Leaded premium gasoline
- Gasoline having an antiknock index: (R+M/2) greater than 90 and containing more than 0.05 grams of lead or 0.005 grams of phosphorus per gallon.
- Leaded regular gasoline
- Gasoline having an antiknock index: (R+M/2) greater than or equal to 87 and less than or equal to 90 and containing more than 0.05 grams of lead or 0.005 grams of phosphorus per gallon.
- Lead-free gasoline
- Until 1973 all new vehicles used Gasoline that had Tetraethyl lead or some other lead Compound as an Additive to increase octane rating and reduce Knock or Detonation. In 1973, almost all new cars required lead-free Gasoline (Unleaded gas). The Exhaust valves in older cars were lubricated by the lead, so they were redesigned to accommodate the new Gasoline. To offset the Detonation problem, the Compression ratio was also reduced. Lead-free Gasoline was introduced to remove the lead in the Exhaust fumes as a health hazard.
- Lead-free petrol
- British term for Lead free gasoline
- Lead glazing
- A faulty spark plug condition caused by molten lead salt deposits that solidify into a yellow, brown, or green glaze
- Leading arm
- A Suspension system which has two long arms that extend forward from the pivot points of the arms. The wheels are attached to the forward end of these arms. The Citroën 2CV has this form of Independent suspension. Compare Trailing arm
- Leading edge
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- The forward edge (e.g., of a body panel). Compare Trailing edge
- In reference to a wind energy conversion system, the area of a turbine blade surface that first comes into contact with the wind.
- Leading link
- A Suspension link that is aligned to resist longitudinal motions in a wheel; it is mounted to the chassis behind the wheel. The axle is mounted at the front end of two short links that pivot at the bottom of solid forks, The link s are sprung to control movement. A long leading-link system has a complete fork that pivots behind the wheel
- Leading power factor
- A designation of the relative instantaneous direction of the currents to the voltages: (angle is 0 to -90°).
- Leading shoe
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- The British term for Primary shoe, the shoe of a brake drum system which pivots outwards into the approaching drum. Compare Trailing shoe
- A shoe whose friction surface leads ahead of the shoe pivot point and is forced against the drum by drum rotation.
- Lead sled
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See
- Leadsled
- A typical body style of a custom car that became popular in the USA in the 1950s such as the Mercury; the term derives from the fact that large amounts of body lead are required to achieve the smooth body lines desired
- Lead weight
- A balance weight on a wheel rim. Also called Wheel weight.
Also see
- Lead wire
- A welding term referring to the electricity carrying wire from the power source to the electrode holder or to the ground clamps.
- Lea Francis
- A vehicle brand of which the 1950-54 Lea Francis 2.5 Liter Eighteen Sports models are milestone cars.
- Leaf spring
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A length of Flat spring steel plates bent in an arch usually with curled ends (eyes) to allow mounting to the Frame. The eyes are usually filled with rubber bushings to reduce noise when the leafs flex. A bolt through the front eye secures the spring to the frame, and a pin through the rear eye attaches the spring to a Shackle. Another pin attaches the shackle to the frame. The pivoting shackle accommodates the changes in the effective length of the spring as it flexes. The axle housing is secured to the leaf spring with two U-bolts on either side. Some applications need only one leaf spring; but most have several leaves, each smaller than the other, nested together to help the main spring. Rebound clips are used at the ends to hold several leafs together to keep them from separating sideways. In a single-leaf application, sometimes two holes are drilled in the center of the main spring to mount a u-bolt which surrounds the axle. Also called semi-elliptic springs.
Leaf spring
Also see
- Leak detector
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- Any device used to detect leaks in an air conditioning system (dye, solutions, electronic, propane, etc)
- Device used to detect and locate refrigerant leaks.
- Device or instrument such as a halide torch, an electronic sniffer, or soap solution used to detect leaks.
- Leak down tester
- The leak-down tester is similar to a compression tester, except the engine does not need to be cranked over. Instead, the leak-down tester pressurizes the cylinder and then measures the amount of cylinder pressure lost through worn piston rings. This lost pressure is called blow by and can indicate a defective valvetrain or blown head gasket.
- Lean
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- A weak air/fuel mixture that has less fuel to air ratio. The opposite is Rich.
- A lateral movement where one side lists more than the other.
- Lean Authority Limit Switch
- A device developed by GM to monitor heated carburetor inlet air through an air cleaner TVS and to prevent the control unit from providing the carburetor with too lean a mixture, for better performance when starting from cold
- Lean-burn engine
- An engine which uses a lean mixture of fuel and air to increase fuel economy and reduce exhaust emissions.
Also see
- Lean mixture
- A mixture of air and fuel in which there is more air and less fuel.
The opposite is Rich mixture.
Also see
- Lean NOx Catalyst
- (LNC) Catalyst designed to reduce nitrogen oxides from diesel or spark-ignited engine exhaust gases under net oxidizing conditions, i.e., in the presence of excessive amount of oxygen.
- Lease term
- The duration of the lease. 24 and 36 month leases are the most common but you can lease a vehicle for 12, 48, or even 60 months if you choose. Remember that your monthly payment will change depending on the length of the lease.
- Leasing
- The financial plan like renting where you pay a sum of money each month in return for the use of a
vehicle instead of buying it outright. Open-end leases allow you to pay an additional amount at the end
of the term so that you can own the vehicle. Sometimes this is called the buy-back option. Closed-end
leases state that at the end of the term the ownership and possession of the vehicle must revert back
to the leasing agency. Leasing used to be the domain of businesses; but because of the high cost of
vehicles, leasing is now an option for the average consumer.
Also see
- Leathers
- Apparel worn by those riding motorcycles. They consist of a leather jacket and leather trousers. Their purpose is to reduce the possibility of injury in the event of a fall; but they also provide warmth when riding because the rushing air will tend to cool off the rider.
- Leather upholstery
- Vehicle seating that is covered in leather. Usually found on upscale vehicles or as an extra-cost option.
- LED
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- Acronym for Light Emitting Diode.
- A semiconductor device used for digital displays in the instrument panel and in taillights in place of bulbs because of their low power usage, durability, and brightness.
- Left
- When referring to the side of a unit, the left side is always from the perspective of operation. In other words, when sitting in the Driver's seat or when pushing a mower, the left side is the operator's left side.
- Left-hand drive
- (LHD) A steering system where the steering wheel is located on the left-hand side of the vehicle; used for driving on the right, as in most parts of the world, except for the UK, Australia, Hong Kong, and Japan. The opposite is Right-hand drive (RHD)
- Left-handed monkey wrench
- A fictitious tool. A monkey wrench is a pipe wrench, a wrench with an adjustable jaw.
- Left hand gear lever
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A device which is attached to the gear lever on the right side of the steering column which allows those who have no use of their right hand to shift gears.
Left hand gear lever
- Left hand rule
- To determine direction of lines of force, grasp conductor with left hand thumb extended in direction of current flow. Fingers indicate direction of lines of force
- Left-hand thread
- Most threads on bolts and screws have Right-hand thread meaning that turning the bolt Clockwise inserts or tightens the bolt; Counterclockwise loosens or removes the bolt. But in left-hand thread the reverse is true. Turning the bolt Clockwise loosens or removes the bolt. Left-hand thread is used on applications where the normal turning motion of the object is such that there is a possibility that the object could back out and be removed. For instance, the left pedal of a Bicycle turns around the Crankarm in a Counterclockwise direction. If it had right-hand thread, the pedal could fall off. Thus all left pedals have left hand thread so that the motion of the pedal helps to keep the pedal tight on the Crankarm.
- Legend
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A model of automobile from Acura
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Legend
- Legionnaire's disease
- Disease named after an outbreak of the illness at an American Legion convention in July, 1 976. The specific cause of the disease is uncertain.
- Le Grand Livre
- Literally the big book which lists every Paris-Brest-Paris bicycle finisher going back to 1891.
- LE-Jetronic
- The LE-Jetronic system incorporates the advantages of direct airflow measurement with the enhancements afforded by electronics. Electromagnetically actuated injectors inject fuel onto the intake valves. Each cylinder has its own solenoid injector which is actuated once with every crankshaft revolution. The injectors are opened by control pulses delivered by the ECU; the length of these pulses depend on the quantity of inducted air, engine speed and other parameters. All of these parameters are detected by sensors and processed in the control unit
- Le Mans
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A model of automobile manufactured by Pontiac division of General Motors
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Pontiac Le Mans
- Length of Fastener
- The length of a flat bearing surface fastener is the distance, in a line parallel to the axis, from the bearing surface to the extreme point. The length of a countersunk head fastener is the distance, in a line parallel to the axis, from the largest diameter of the bearing surface to the extreme point.
- Length, overall
- The extreme length of a ship measured from the foremost point of the stem to the aftermost part of the stern
- Lens
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- A specially treated glass through which a welder may look at an intense flame without being injured by the harmful rays, or glare, radiating from this flame.
- A glass or plastic front cover of a headlight through which the light converges or diverges.
- A glass or plastic covering of a signal light, taillight, backup light, etc.
Also see
- Lentil Head Screw
- Obsolete term for oval head screw
- LeSabre
- A model of automobile manufactured by Buick Division of General Motors from 1959-2005
- Lessee
- The individual or party signing the lease contract and taking responsibility for the vehicle and lease payments, i.e., the company or individual which leases vehicles.
- Lessor
- The individual, dealer, business, manufacturer, or financial
institution that owns the vehicle and offers it for leasing.
Also see
- Less Than Load
- (LTL) Situations in which general freight from various shippers is combined into a truck load.
- Let out
- To release, such as to let some air out of the tire or to release the clutch by pushing in the clutch pedal.
- Letter drills
- A series of drills in which each drill size is designated by a letter of the alphabet A, B, C, etc.
- LEV
-
- Acronym for Low-emission vehicle
- Acronym for Low Emission Vehicle Standards.
- Level
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- The condition where an item is perpendicular to the force of gravity.
- The degree of importance, quality, or value. For example a manufacturer may produce the same car in two or more levels of accessories and options.
Also see
- Level control
- A device that maintains the level of a vehicle when it is loaded at one end. When your trunk is heavily loaded, the front of your car is much higher and the headlights are not shining where they should. Level control compensates for the load by adding more compressed air to the shock absorbers to raise the back of the car.
- Level crossing
- Intersecting roads or railroad tracks that are on the same plane rather than one of them in an overpass.
- Leveled suspension
- A means of eliminating the "squat" of the rear suspension under load by a hydraulic self-leveling unit between the chassis and the center of the rear axle. Standard on up-scale automobiles.
- Leveling
- Placing a variable-thickness course of materials to restore horizontal and vertical uniformity to existing pavements, normally continuous throughout the project. British spelling is levelling.
- Leveler (Leveller)
- A component in continuous sheet galvanizing lines by means of which steel strips are stretched and leveled
- Level of service
- A standard of performance defined by a local government detailing the types and amounts of winter maintenance needed to achieve desirable road conditions
- Level out
- To work on a panel to remove irregularities with the use of hammer and dolly or by filling and sanding, etc.
- Level plug
- A threaded plug in the side of a gearbox or rear axle to determine if sufficient oil has been used during filling
- Level tube
- In a tool which is designed to determine if an object is parallel with the ground, there is a glass cylinder (i.e., the level tube) which contains a liquid and a small air bubble. The object is level when the bubble is centered within the tube.
- Leverage
- The use of a lever and fulcrum to create a mechanical advantage. The brake pedal is an automotive part that employs leverage.
- Levering bar
- A metalworking tool shaped like a large tire iron with flat hooked ends for levering bent panels back into position
- Lever-type shock absorber
- A spring damper operated by a lever arm from a chassis-mounted hydraulic damper unit.
Also see
- Lexus
-
An upscale model of automobile manufactured by Toyota including ES 250 (1990-91), ES 300 (1992-2003), ES 330 (2004-06), ES 350 (2007-08), GS 300 (1993-2006), GS 350 (2007-08), GS 400 (1998-2000), GS 430 (2001-07), GS 450h (2007), GX 470 (2003-07), IS 250 (2006-08), IS 300 (2001-05), IS 350 (2006-08), LS 400 (1990-2000), LS 430 (2001-06), LS 460 (2007), LX 450 (1996-97), LX 470 (1998-2007), RX 300 (1999-2003), RX 330 (2004-06), RX 350 (2007-08), RX 400h (2006-07), SC 300 (1992-2000), SC 400 (1992-2000), and SC 430 (2002-07)
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Lexus