Parking pawl


A parking pawl is a device fitted to a motor vehicle's automatic transmission that locks up the transmission when the transmission shift lever selector is placed in the Park position. "Park" is the first position of the lever in all cars sold in the United States since 1965 through SAE J915, and in most other vehicles worldwide.

Mechanism

The parking pawl locks the transmission's output shaft to the transmission casing by engaging a pawl that engages in a notched wheel on the shaft, stopping it 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 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.

Standards