| Automotive transmissions |
|---|
| Manual |
| Automatic /Semi-automatic |
Aparking pawl is a device fitted to amotor vehicle'sautomatic transmission that locks up thetransmission when thetransmission shift lever selector is placed in thePark position. "Park" is the first position of the lever (topmost on a column shift, frontmost on a floor shift) in all cars sold in the United States since 1965 (when the order was standardised by theSociety of Automotive Engineers (SAE)) throughSAE J915,[1] and in most other vehicles worldwide.
The parking pawl locks the transmission'soutput shaft to the transmission casing by engaging apawl (a pin) that engages in a notched wheel on the shaft, stopping it (and thus the driven wheels) from rotating. The main components of a parking pawl mechanism are the parking gear, parking pawl, actuator rod, cam collar, cam plate, pivot pin, and parking pawl return spring. The mechanism assembly is designed so that the parking pawl tooth collides and overrides the parking gear teeth (ratchets) until a safe engagement speed for the vehicle is reached. Software controls are put in place to avoid this condition and engage the pawl only when the vehicle has come to a standstill.[2]
