DICTIONARY OF AUTOMOTIVE TERMS - "Le"

Lea:

A vehicle brand of which the 1950-54 Francis 2.5 Liter Eighteen Sports models are milestone cars.

Lead:

1. [pronounced LEED] A short connecting wire which makes electrical contact between two points.
2. [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.
3. [pronounced LED] A soft, toxic, heavy metal used in storage batteries, and as an anti-knock agent added to gasoline in the form of tetraethyl lead.

Also See:
body lead
coil lead
high tension lead
HT lead
ignition lead
jump lead
low tension lead
paddling the lead
red lead
spark plug lead
spongy lead
tetraethyl lead
tetramethyl lead

Lead-acid battery:

An electricity producing system of lead plates and dilute sulphuric acid; used as a starter battery and as a traction battery in electric vehicles or as a source for lights because they are rechargable, inexpensive, and durable

Lead acid rechargable battery:

Used in many light systems. Benefits include low cost and solid long term durability.

Lead and lag:

The terms referring to 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-antimony grid:

See grid

Lead ballast:

See dry ballast.

Lead burning:

Joining two lead pieces by melting or fusing the metal where they touch each other

Lead deposit:

Lead particles that separate from the battery plates during normal operation

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

Leaded petrol:

British term for leaded gasoline

Leaders:

See loss leaders

Lead free:

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 gasoline:

See lead free

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:

Forward or at the front.
Also See:
double leading brake shoe

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 brake shoe:

See:
primary forward brake shoe
single leading brake shoe
double leading brake shoe

Leading edge:

The forward edge (e.g., of a body panel). Compare trailing edge

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 shoe:

1. The British term for primary shoe, the shoe of a brake drum system which pivots outwards into the approaching drum. Compare trailing shoe
2. A shoe whose friction surface leads ahead of the shoe pivot point and is forced against the drum by drum rotation.

Leading-trailing brake:

A non-servo brake with one leading and one trailing brake shoe

Lead loading:

The process of filling dents and damaged areas of the bodywork with body lead

Lead peroxide:

A poisonous compound used, for example, as an electrode in batteries

Leads:

See:
carbon-core leads
high-tension leads
high tension leads
low tension leads

Lead sled:

See leadsled

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 sulphate:

Chemical compound; poisonous white crystals found in discharged batteries

Lead tolerance:

Resistance to leaded fuel

Lead weight:

A balance weight on a wheel rim. Also called wheel weight.
Also See:
red lead

Lead wire:

A welding term referring to the electricity carrying wire from the power source to the electrode holder or to the ground clamps.

Leaf:

See:
auxiliary leaf
helper leaf
leaf spring
longitudinal leaf spring
quarter-elliptic leaf spring

Leaf spring:

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.
Also See:
longitudinal leaf spring
quarter-elliptic leaf spring
semi-elliptic leaf spring
tapered leaf spring
taper leaf spring
transverse leaf spring

Leak:

See:
helium leak test
slow leak
stop-leak

Leakage:

See compression leakage

Leak detector:

1. Any device used to detect leaks in an air conditioning system (dye, solutions, electronic, propane, etc)
2. Device used to detect and locate refrigerant leaks.
3. 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.

Leak-off pressure:

Manufacturer-specified pressure used to test injector leakage on a pop tester

Leak test:

See helium leak test

Lean:

1. A weak air/fuel mixture that has less fuel to air ratio. The opposite is rich.
2. A lateral movement where one side lists more than the other.

Lean air-fuel mixture:

A mixture of air and fuel in which there is more air and less fuel. See air-fuel ratio.

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:
CACIS

Lean mixture:

A mixture of air and fuel in which there is more air and less fuel. See air-fuel ratio. The opposite is rich mixture.
Also See:
stoichiometric ratio

Lease:

Form of contract transferring the use of a vehicle in consideration of payment.
Also See:
closed end lease
off-lease
open end lease
subsidized lease
subvented lease

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.

Leather:

See:
chamois leather
full leather upholstery
full leather

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:

See full leather upholstery

LED:

1. Acronym for "Light Emitting diode."
2. 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.

Ledballast:

See dry ballast.

Ledge:

See:
safety ledge
special ledge

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 hand gear lever:

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 monkey wrench:

See left-handed monkey wrench.

Left-handed monkey wrench:

See left-handed monkey wrench.

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:

See left-hand thread.

Left-hand thread:

Most threads on bolts 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.

Left handed monkey wrench:

See left-handed monkey wrench.

Left-handed monkey wrench:

A fictitious tool. A monkey wrench is a pipe wrench, a wrench with an adjustable jaw.

Left thread:

See left-hand thread

Leftward welding:

Welding a seam towards the left

Leg:

See chassis leg

Legere:

See voiture Legere

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.

Leg of fillet weld:

Distance from point where the base metals touched to toe of the fillet.

Le Grand Livre:

Literally "the big book" which lists every Paris-Brest-Paris bicycle finisher going back to 1891.

Legroom:

The amount of space available to move one's legs in a vehicle

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:

A model of automobile manufactured by Pontiac division of General Motors
Click image for books on Pontiac Le Mans

Lemna:

See bridge.

Lemon:

A new or used car with many defects

Length:

See:
floodable length
free length
nominal length
overall length
shank length

Length between perpendiculars:

The length of a ship between the forward and after perpendiculars

Length, overall:

The extreme length of a ship measured from the foremost point of the stem to the aftermost part of the stern

Lens:

1. 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.
2. A glass or plastic front cover of a headlight through which the light converges or diverges.
3. A glass or plastic covering of a signal light, taillight, backup light, etc.

Also See:
diffusing lens

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:
independant lessor

Let in:

To engage, such as to engage the clutch slowly

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 drill:

See letter drills.

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 Standards.

Level:

The condition where an item is perpendicular to the force of gravity.
Also See:
acceptable quality level
automatic level control
bac level
blood alcohol level
engine oil level warning light
float level
fluid level warning indicator
interior noise level
oil level
oil level gauge
oil level sensor
spirit level
trim level

Level control:

See automatic level control.

Level gauge:

See oil level gauge

Leveling:

See:
automatic level control
headlight leveling control
ride levelling
roller levelling

Leveling control:

See headlight leveling control

Leveller:

A component in continuous sheet galvanizing lines by means of which steel strips are stretched and levelled

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

Levels:

See emission levels

Level sensor:

See oil level sensor

Level warning:

See:
engine oil level warning light
fluid level warning indicator

Level warning indicator:

See fluid level warning indicator

Level warning light:

See:
coolant level warning light
engine oil level warning light

Lever:

A simple machine comprising an arm and a pivot.
Also See:
actuating lever
brake lever
clutch lever
clutch release lever
gear lever
gearshift
left hand gear lever
parking brake lever strut
parking brake lever
relay lever
release lever
roller foot lever
selector lever
shift lever
throwout lever
tire lever

Leverage:

The use of a lever and fulcrum to create a mechanical advantage. The brake pedal is an automotive part that employs leverage.

Leverage diagonal cutting pliers:

See high leverage diagonal cutting pliers

Levering bar:

A metalworking tool shaped like a large tire iron with flat hooked ends for levering bent panels back into position

Lever lock:

See selector lever lock

Lever strut:

See parking brake lever strut

Lever-type shock absorber:

A spring damper operated by a lever arm from a chassis-mounted hydraulic damper unit.
Also See:
telescopic shock absorber

Leviathan:

A big multi-cylinder dual sport bike

Lexus:

A model of automobile manufactured by Toyota
Click image for books on Lexus

Leyland:

See:
British Leyland

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