In an automatic transmission, the Park position engages a mechanical locking device called a parking pawl. This metal pin drops into the teeth of a gear on the transmission output shaft, physically preventing the drive wheels from turning. It is the mandatory gear selection for leaving a vehicle stationary, though it should always be used alongside the parking brake to avoid putting excessive stress on the internal pawl.
Heard on the job
Make sure it's fully in Park before you take your foot off the brake, or you'll snap the pawl on this incline.
Insider tip
Never shift into Park while the vehicle is still moving. The grinding noise you hear is the parking pawl skipping over the gear teeth, which can sheer off the metal.
Also heard as
- P