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Panhard Rod

A rod that is attached to the vehicle frame at one end and to the axle at the other end to prevent the chassis from moving side to side relative to the axle; used on a beam axle or de Dion axle type rear suspension.

Paper

Sheets of fibrous absorbent materials made from organic fibers that will "swallow up" liquids and may well disintegrate under such action if the liquid is a solvent for the binder.

Parabolic Reflector

A reflector in the shape of a concave parabola used for radar and other microwave antennas.

Parade Lap

A lap or laps in closed-course racing before the pace lap to give the drivers an opportunity to warm up their tires and engines and to give the fans a chance for a good look at the cars at a slow speed.

Parallax Error

This is an error that occures if the pointer of an analoge meter is viewed from any angle execpt stright on, or if a timing light flash is viewed at an angle.

Parallel Circuit

An electric circuit having two or more paths that the current flows through at the same time. The current is divided with more of it flowing through the path of least resistance.

Parallel Linkage

A steering linkage having equal-length tie rods.

Parallel-joint Type

A drive shaft installation whereby all companion flanges and/or yokes in the drive line are parallel with each other with the working angles of the joints of a given shaft being equal and opposite.

Parallel-series Circuit

A circuit with several parallel branches, each branch containing one or more series components.

Parallelogram Linkage

A steering linkage system having a short idler arm mounted on the right side in such a manner that is parallel to the pitman arm.

Parameter

A particular measured value that characterizes the behavior of an electronic unit or device.

Parasitic Drag

Any interference of the aerodynamic efficiency of a vehicle body such as may be caused by outside mirrors, door handles, antenna, and windshield wiper arms and blades.

Parasitic Load

An electrical load that is present when the ignition switch is in the OFF position.

Parent Metal

The original metal in a body panel to which another metal panel has been added.

Parity

An error-checking scheme whereby additional bits are added to data to aid in detecting common errors in data transmissions.

Park Contacts

Electrical contacts, inside a windshield-wiper motor assembly, to provide current to the motor after the control switch has been turned to the OFF or PARK position, allowing continued motor operation until reaching the park position.

Park Neutral Switch

Used on vvehiclesequipped with automatic transmissions to indicate the transmissions shifted postion.

Parking Brake Control

The pedal of lever used to apply the parking brakes.

Parking-brake Cable

A cable or cables that transmit brake-actuating force in the parking-brake system.

Parking-brake Equalizer

A device used to equalize the pull between the parking brake actuator and two rear wheels.