Reversible wheel: A wheel whose disc can be mounted on either face to provide 'inset' or 'outset', thus decreasing or increasing the wheel track.

Regenerative braking: Form of braking in electronic or electric hybrid vehicles in which energy of road wheels of moving vehicle is used during braking, to…

Rebound: Wheel motion when it moves down relative to the body.

Ratchet screw driver: A screw driver with a ratchet mechanism.

Ratchet: A feature of a special wrench which allows you to turn the handle in one direction to tighten a nut or bolt, but on…

Radius rod or Thrust member: The member connecting the axle casing and the chassis frame in the longitudinal direction, which transmits the driving thrust from…

Radial tyre: A tyre which has body cords running at right angles to the tyre centre line. Two or more belts are used to give…

Propeller shaft: This is the shaft which transmits the drive from the transmission (gear box) to the bevel pinion or worm of final drive in…

Pressure plate: A spring-loaded plate (part of the clutch) which transmits power to the driven (i.e. friction) plate when the clutch is engaged.

Ply rating: It is a relative index of tyre strength and load- carrying capacity. It does not indicate exact number of plies in the tyre.

Pitman arm: A lever which transmits steering force and motion from the steering gear to the steering linkage.

Pitch: A vehicle is said to pitch when the front end rises while the rear end falls, or vice versa.

Perfect steering: The steering condition when all the four wheels of the vehicle are rolling perfectly.

Payload: The weight of the commodity being hauled in the vehicle.

Panhard rod: Also called track bar, it is the suspension link connecting the vehicle body at one end and the live axle beam at the…