DICTIONARY OF AUTOMOTIVE TERMS - "Pl"

PL
Acronym for Parking lock
PL&PD
Acronym for Public Liability and Property Damage as a form of basic Car insurance
Place in service
A vehicle is placed in service if that vehicle is new to the fleet and has not previously been in service for the fleet. These vehicles can be acquired as additional vehicles (increases the size of the company fleet), or as replacement vehicles to replace vehicles that are being retired from service (does not increase the size of the company fleet).
Plain bearing
A cylindrical sleeve friction bearing; most commonly used type of bearing.
Also See
Ball bearing
Needle bearing
Roller bearing
Plain carbon steel
See
Carbon steel
Plain disc wheel
A type of wheel without holes or slots in the wheel disc
Plain gage tubing
See
Plain gauge tubing.
Plain gauge tubing
Tubing whose thickness remains constant over its entire length.
Plain Sheared Point
The end of a metal object cut approximately flat and square to the axis, without chamfer.
Plain wrapper
Trucker slang for an unmarked police car as in "Plain wrapper sitting at the 57 taking pictures."
Plan
See
Body plan
Capacity plan
Lines, plan
Planar cells
See
Flat plate cells.
Plane
A flat surface.
Also see
Inclined plane
Planer Head Bolt
A bolt having a large, low square head, designed for insertion in T-slots of planer, shaper, or milling machine tables.
Planes
See
Buttock Planes
Cardinal Planes
Plane sailing
A method of navigation which ignores the earth's curvature, treating its surface as a plane. Colloquially it indicates travel or procedure without difficulty or obstruction.
Planet
See
Twin Planets
Planetary albedo
The fraction of incident solar radiation that is reflected by the Earth-atmosphere system and returned to space, mostly by backscatter from clouds in the atmosphere.
Planetary gear
A gear used in some starters as an intermediate transmission
Also see
Stepped Planet Gear
Planetary gear differential
A planetary gear set used as a differential with asymmetric torque distribution, as used in 4WD vehicles
Planetary gears
See
Planetary gearset.
Planetary gearset
  1. A Gearing unit consisting of a Ring gear with internal teeth, a sun or central Pinion gear with external teeth, and a series of Planet gears that mesh with both the ring and the Sun gear. Frequently used in Overdrives and Automatic transmission. Also called Epicyclic gearbox.
  2. A central externally toothed sun gear, an internally toothed outer ring gear, and several intermediate planet gears which are evenly spaced and supported by a planet carrier; they are in constant mesh with the sun gear and the internal gear
Also See
Ravigneaux planetary gear set
Simpson planetary gear set
Planetary gear set
See
Planetary Gearset
Planetary-gear system
A gearset used in automatic transmissions that features a central gear, called a sun gear, surrounded by two or more smaller planetary gears that mesh with a ring gear.
Planetary set
See
Ravigneaux planetary gear set
Planetary transmission
A form of gear used by Benz in which small Pinions revolve around a central or Sun gear and mesh with an outer Ring gear called the annulus. Type used in the Ford Model T. Also called Epicyclic gearbox and "sun-and-planet gears".
Planet carrier
That part of a Planetary gearset upon which the Planet gears are affixed. The planet gears are free to turn on hardened pins set into the carrier. The planet carrier revolves around the central axis of a planetary gear set and supports the planet gears
Planet gear
See
Planet gears
Stepped planet gear
Planet gears
Those gears in a Planetary gearset that are in mesh with both the ring and the Sun gear. They are referred to as planet gears in that they orbit or move around the central or Sun gear.
Also See
Stepped planet gear
Planet pinion
See
Planetary gearset
Planets
See
Twin planets
Planet spider
A common type of Planet carrier with a Spider or web-style design
Planet wheel
See
Planetary gearset
Planishing
The final panel hammering stage for lifting out minor imperfections in a panel surface. Part of the panel finishing process
Planishing hammer
Planishing hammer

Planishing hammer

A specialized hammer used in repairing damaged body work

Planck's constant
Constant value (6.626 x 10-34 watt seconds squared) which, when multiplied by the frequency of radiation, determines the amount of energy in a photon.
Plan lines
The plans that show the shape or form of the ship
Planned obsolescence
A policy of manufacturers that encourages motorists to become dissatisfied with their cars so that they are eager to buy the latest model.
Planning
See
Product planning
Plant
See
Alternative Power Plant
Automatic Generating Plant
Auxiliary Plant
Blending Plant
Diesel-electric Plant
Pressing Plant
Plant condensate
One of the natural gas liquids, mostly Pentanes and heavier hydrocarbons, recovered and separated as liquids at gas inlet separators or scrubbers in processing plants.
Plant Liquids
See
Production Plant Liquids
Plant products
Natural gas liquids recovered from natural gas processing plants (and in some cases from field facilities), including ethane, Propane, Butane, butane-propane mixtures, natural gasoline, plant condensate, and lease condensate.
Plaque
See
Dashboard plaque
Dash Plaque
Plasma
Temporary physical condition of a gas after it has been exposed to and has reacted to an electric arc.
Plasma arc cutters
Cutting equipment that makes clean, fast cuts without destroying the properties of high-strength steels
Plasma spray process
The process in which a very high temperature flame is produced by blowing gas through an electric arc. Metal wire or powder is melted by passage through the flame and is projected on the surface to be coated
Plastic
A material that contains as an essential ingredient one or more organic polymeric substances of large molecular weight. It is solid in its finished state and, at some stage in its manufacture or processing into finished articles, can be shaped by flow.
Also See
Fiber Reinforced Plastic
Glass reinforced plastic
Hydrocarbon plastics
Plastic deformation
A permanent change in the shape or size of a solid body without fracture resulting from the application of sustained stress beyond the elastic limit
Plastic engine
An automobile engine whose bulk is made of plastic components (e.g., engine block, inlet manifold, water-pump housing, valve covers, oil pan), the use of metal being limited to parts subjected to extreme mechanical or thermal loads (e.g., combustion chamber, exhaust manifold, pistons, cylinder liners, valve train, etc.)
Plastic filler
See
Polyester filler
Plasticize
  1. To soften a material to make it plastic or moldable by heating, kneading, or adding a plasticizer
  2. To soften an adhesive, coating or sealer, generally by the addition of high boiling liquids or plasticizers
Plasticizer
  1. An additive that gives flexibility to an otherwise rigid plastic
  2. A liquid or solid chemical added to a compound to impart softness or flexibility. Some plasticizers have an undesirable tendency to migrate from the parent material into nearby surfaces which are receptive. When they migrate into adhesive films, for instance, they generally cause loss of strength or complete failure of the bond
Plastic molding
A process that converts organic-based materials, by means of a general-purpose press and purpose-built Tooling under controlled heat and pressure, and injects the hot material into a die cavity shaped in the final form of the intended part.

Plastics welding
A uniting of thermoplastic, i.e., non-setting plastics of similar or different type using heat and pressure and with or without the addition of plastic of a similar kind (filler material). The welding proceeds within the temperature range of thermoplasticity of the contact surfaces on the parts to be welded; the freely mobile molecular chains in the marginal areas flow together and become interlaced
Plastigage
A soft plastic that flattens out to predetermined widths when subjected to torque; these widths equal a specific clearance. It is normally used to check main and rod-bearing clearance. It is sold in a paper sleeve that also doubles as the scale on which it is measured (in thousandths of an inch)
Plastigauge
A plastic material that compresses to the thickness of the clearance between a crankshaft journal and a bearing when the bearing retaining cap is installed, so the clearance can be checked against specifications
Plate
  1. The action of Coating a material with some metal. Also called Electroplate or Anodize.
  2. A flat piece of material often used to mount another device.
  3. Two lead-alloy plates in each cell of a battery where the positive plate is made of lead peroxide and the negative plate is made of spongy lead. The plates are arranged in groups, in an alternate fashion, called elements. Separators are placed between the plates of different polarity. Plates and separators are completely submerged in the Electrolyte.
  4. The electrode, in a valve or tube, held at a positive potential with respect to a cathode, and through which positive current generally enters the vacuum or plasma, through collection of electrons.
  5. Clutch discs
  6. The electro-chemical coating of a metal piece with a very different metal.
Also See
Adapter plate
Anchor Plate
Armature End Plate
Armor Plate
Backing plate
Baffle plate
Bipolar Plates
Blanking plate
Boiler Plate
Brake backing plate
Breaker plate
Buckled Plates
Catch Plate
Center drive plate
Chafing plate
Clutch plate
Clutch pressure plate
Contact breaker plate
Directional Baffle Plate
Driven plate
Drive plate
End cover plate
Flitch plate
Friction plate
Gusset plate
Heel plate
Hinge plate
Hinge tapping plate
Hub plate
Identification Plate
Intel-plate
Intermediate drive plate
Intermediate plate
Keel, flat plate
License plate
License plate frame
Nave plate
Negative plate
Positive plate
Pressure plate
Quarter-wave Plate
Rear license plate lamp
Rear license plate light
Restrictor plate
Retainer plate
Scuff plate
Sensor plate
Separator Plate
Short Circuit Between The Plates
Skid plate
Step plate
Striker plate
Support Plate
Surface Plate
Swash plate
Swash Plate-wobble Plate
Transfer plate
Valve body separator plate
Valve plate
Vanity plate
Wobble Plate-swash Plate
Plated
See
Armor-plated
Cadmium-plated
Chrome-plated
Chromium-plated
Plate frame
See
License plate frame
Plate grid
See
Grid
Plate group
An assembly of plates of identical polarity (positive or negative) used in a battery cell
Plate keel
See
Flat plate keel
Plate lamp
See
Rear license plate lamp
Plate light
See
Rear license plate light
Plate strap
The conducting connection between the lugs of battery plates of like polarity and the cell terminal
Plate support
The support at the bottom of a battery case on which the elements rest. It provides space for the sediment chamber
Plate-swash Plate
See
Wobble Plate-swash Plate
Plate-wobble
See
Swash Plate-wobble Plate
Platform
Primary load-bearing structural assembly of a motor vehicle determining the basic size of the motor vehicle, and is the structural base that supports the driveline and links the Suspension components of the motor vehicle.
Also see
Lifting platform take-up point
Platform Bus
See
High Platform Bus
Platform frame
The underbody construction consisting of a reinforced and fairly flat section that forms the entire lower portion of a vehicle. It includes the floorpans and is bolted to the body; (e.g., Volkswagen Beetle)
Platform pedal
Older style pedal that the foot rests on top of and is not locked into.
Platform take-up point
See
Lifting platform take-up point
Platform Trailer
A flatbed trailer. There are straight platforms, single drops, and double drops.
Plating
The coating of metal usually by electrolysis.
Also See
Barrel Plating
Black chromium plating
Bright Plating
Brush Plating
Chromium plating
Copper plating
Gold plating
Hard chromium plating
Mechanical plating
Nickel plating
Shell plating
Silver-plating
Zinc plating
Platinum
A precious light-grey, heavy, ductile, noble metal, atomic number 78, atomic weight 195.09; melting point at 1769°C. It is the main member of the so-called platinum metals. Together with other platinum metals, it is used as a catalyst in automotive exhaust converters. It is used in the construction of Breaker points. It conducts electricity well and is highly resistant to burning.
Platinum electrode
A spark plug electrode made of platinum which lasts longer than one of nickel alloy because it can better withstand high temperatures
Platinum metals
A generic term for a family of noble metals found with and resembling platinum. It includes ruthenium, rhodium, palladium, osmium, iridium, and platinum. They are used as catalysts in catalytic converters. Less than a tenth of a troy ounce is required per converter to produce acres of catalytically active catalyst surface
Platinum spark plug
A spark plug with a platinum center electrode
Platinum-tipped spark plugs
Most General Motors vehicles built since 1995 are equipped with platinum-tipped spark plugs. Under normal operating condition, platinum-tipped spark plugs are designed to function up to 166,000 km. They are designed to operated with a wider gap. The electrode is platinum-tipped and the body is stainless steel.
Play
Movement between two parts.
Also See
Camshaft end play
End play
Free pedal play
Free play
Pedal free play
Radial play
Playback
See
Quasi S-VHS Playback
Player
See
Cassette player
CD player
Plenum
  1. A chamber, located between the Throttle body and the runners of an Intake manifold, used to distribute the intake charge evenly and to enhance engine breathing.
  2. An enclosure containing air or gas at a higher pressure than exists outside.
  3. The air ducts, air valves and blower assembly inside the dash
Plenum chamber
  1. A large cast alloy body in an induction system which connects the throttle body or inlet tube to the cylinder head(s) or inlet manifold.
  2. The air compartment in a car body formed between the scuttle and the bulkhead, providing a basis for the interior air supply
  3. Chamber or container for moving air or other gas under a slight positive pressure.
Plexiglas
A trade name for an Acrylic plastic, made by the Rhom and Haas Co.
Plexiglass
See
Plexiglas.
Pliers
A gripping tool with two hinged arms and serrated jaws.
Also See
Angle-nose pliers
Bending pliers
Combination pliers
Crimping pliers
End cutting pliers
Eyelet pliers
Flat-nosed pliers
Flat-nose pliers
General purpose pliers
Half-moon slip joint pliers
Heavy-duty diagonal cutting pliers
Heavy-duty end cutting pliers
High leverage diagonal cutting pliers
High leverage end cutting pliers
Hose clamp pliers
Hose clip pliers
Hose pinch-off pliers
Internal circlip pliers
Locking pliers
Lock ring pliers
Long-nose pliers
Long-nose self-grip pliers
Multigrip pliers
Parallel action locking pliers
Piston ring pliers
Radiator hose shark tooth pliers
Spark plug pliers
Thin needle-nose pliers
Valve shim pliers
Valve stem seal pliers
Plies
See
Ply
Stabilizing plies
Tire plies
PLL circuitry
A phase-locked loop circuitry in a radio which locks the station frequencies to ensure utmost frequency stability
Plow bolt
Plow bolt

Plow bolt

A bolt with a countersunk, flat head, square neck, and unified thread pitch. Used in road graders, scoop shovels and other heavy-duty equipment where a smooth surface is required at the spot of head protrusion

Plowing snow
Using mechanical means to push or clear snow away from the road surface
Plug
  1. A removable cork or stopper which fills a hole.
  2. A Spark plug.
  3. A male electrical connector.
  4. To seal with a stopper
Also See
Banana Plug
Blanking plug
Cold plug
Drain plug
Drain plug key
Drain plug spanner
Drain plug wrench
End Plug
Expansion plug
Fill plug
Flame glow plug
Freeze plug
Fusible Plug
Glow plug
Glow plug indicator
Glow plug starter switch
Hot plug
Level plug
Magnetic drain plug
Magnetic plug
Oil drain plug
Oil pan drain plug
Platinum spark plug
Platinum-Tipped Spark Plugs
Radiator drain plug
Resistor spark plug
RFI suppressed spark plugs
Rubber plug
Safety Plug
Self-regulating sheathed-type glow plug
Sheathed-type glow plug
Sooted plug
Sooty plug
Spark plug
Spiral-type glow plug
Split electrode spark plug
SR sheathed glow plug
Surface gap spark plug
TC Spark Plug
Thermocouple Spark Plug
Wading plugs
Welch plug
Wire glow plug
Plug boot
See
Spark plug boot
Plug boot puller
See
Spark plug boot puller
Plug brush
See
Spark plug brush
Plug cable
See
Spark plug cable
Plug cable cover strip
See
Spark plug cable cover strip
Plug cable loom
See
Spark plug cable loom
Plug cable marker
See
Spark plug cable marker
Plug cable separator
See
Spark plug cable separator
Plug caddy
A special box which can hold spare spark plugs and is especially used by snowmobilers.
Plug cap
The device on the end of the high tension wire coming from the coil and mounted on the spark plug. Also called Spark plug cap
Plug condition
See
Spark plug condition
Plug electrode
See
Spark plug electrode
Plug gap
See
Spark plug gap.
Plug gapping
Adjusting the side Electrode on a Spark plug to provide the proper Air gap between it and the center Electrode.
Plug gauge
See
Spark plug gauge
Plug Heat Range
See
Spark Plug Heat Range
Plug ignition
See
Twin ignition system
Plug-in diagnosis
On-board computer provides means for special test equipment to be plugged in for making a series of programmed tests to check condition of various units and systems on the vehicle
Plug indicator
See
Glow plug indicator
Plug insert tap
See
Spark plug insert tap
Plug insulator
See
Spark plug insulator
Plughole
The hole in a tank or cistern, which can be closed with a rubber plug
Plug key
See
Drain plug key
Plug lead
See
Spark plug wire
Plug patch
A tire repair material which is forced into a nail hole to fill it. The plug is attached at one end to a patch that seals the hole and then expands to fill the hole. Although a common procedure, it is not the most satisfactory method of repair
Plug pliers
See
Spark plug pliers
Plug repair
The filling of a nail hole by forcing repair material into the damaged area, often while the tire is mounted and containing air. It is not a satisfactory method of repair.
Plug reversal
The reconnecting of an electric motor's windings to reverse its direction of rotation while running
Plug shell
See
Spark plug shell
Plug socket
See
Spark plug socket
Universal Spark Plug Socket
Plug spanner
See
Drain plug spanner
Plug starter switch
See
Glow plug starter switch
Plug tap
Tapping threads in a blind hole
Plug tester
See
Spark plug tester
Plug Valve
See
Lubricated Plug Valve
Plug weld
A weld which holds two pieces of metal together and made in a hole in one of metal which is lapped over the other pieces. Also called rosette weld.
Plug welding
A number of holes are punched along the edge of the repair section to be welded in; the section overlaps the damaged area to be repaired and is welded to the base metal at the punched boles. This is a convenient way of duplicating the spot welding process used by manufacturers, as spot welding equipment is usually too expensive and cumbersome for repair purposes

Plug whiskering
See
Gap bridging
Plug wire
See
Spark plug wire
Plug wire cover strip
See
Spark plug wire cover strip
Plug wire loom
See
Spark plug wire loom
Plug wire marker
See
Spark plug wire marker
Plug wire separator
See
Spark plug wire separator
Plug wrench
See
Drain plug wrench
Spark plug wrench
Plunger
  1. Any immersing type of piston.
  2. A hydraulic tappet component (e.g., in a valve).
  3. An actuating element in an ignition lock.
  4. A piston in a starter solenoid.
Also see
Control plunger
Plunger principle
A new ABS control system which offers improved pressure modulation with very small amplitudes even at pressures close to zero. Compare Valve principle
Plunger pump
An oil pump consisting of a reciprocating plunger in a ported chamber
Plunger suspension
A suspension system in which the vertical movement of the axle is controlled by springs mounted above and below the axle.
Plunging joint
A Slip joint which is a connection in the drive train, of variable length, which permits the drive shaft to change in effective length. The British term is "sliding joint"
Plus
See
Cab Plus
Pentanes Plus
Two plus two
Ply
A layer of rubber-coated parallel cords which forms a unit of a tire carcass. The plies are made of cord, Fiberglass, steel, or structural fabric.
Also See
Bias tire
Conventional cross ply
Radial ply
Tire plies
Plymouth
Plymouth

Click image for books on
Plymouth

A vehicle brand of Chrysler of which the Fury for 1956-58 are Milestone cars. The Satellite SS and GTX for 1965-70 are Milestone cars. The Barracuda Formula S for 1965-69 are Milestone cars. The Roadrunner and Superbird for 1968-70 are Milestone cars. Acclaim (1989-95), Breeze (1996-2000), Caravelle (1983-88), Colt (1971-94), Colt Vista (1988-94), Grand Voyager (1974-2000), Gran Fury (1975-77, 1980-89), Horizon (1978-90), Laser (1990-94), Neon (1995-2001), Prowler (1997-2000), Reliant (1981-89), Sundance (1987-94), and Voyager (1974-2000)

Ply rating
(PR) An indication of tire strength and load carrying capacity. It does not necessarily indicate actual number of Plies. A two-ply four-ply rating tire would have the Load capacity of a four-ply tire of the same size but would have only two actual plies. This system of measurement has been replaced by the term Load range.
Ply separation
A breakdown of the bonding compounds resulting in the plies detaching from each other. Usually as a result of excessive heat.
Ply tire
See
Bias ply tire
Ply turnup
The extension of a carcass ply to its end after wrapping around the bead. Also called "flipper strip"