1. Transmission Selector Position: When the vehicle is put in the "Park" position, the transmission selector lever moves a linkage or cable that is connected to the transmission brake. This initiates the process of engaging the brake.
2. Parking Pawl: Inside the transmission, there's a parking pawl, which is a gear-shaped component. When the transmission brake is activated, the parking pawl moves into position and engages with a corresponding notched gear on the transmission's output shaft or parking gear.
3. Locking Mechanism: The movement of the parking pawl causes it to lock the output shaft or parking gear, effectively preventing the transmission from rotating. This means that the wheels connected to the transmission cannot turn, keeping the vehicle stationary.
4. Release Mechanism: When the transmission brake is released (usually by shifting out of the "Park" position), the parking pawl is disengaged from the notched gear. This allows the transmission to rotate freely again, enabling the vehicle to move when the appropriate gear is selected.
5. Safety Interlock: In most vehicles, there's a safety interlock mechanism that prevents the ignition key from being removed unless the transmission brake is engaged. This feature helps ensure that the vehicle cannot be inadvertently driven away while in the "Park" position.
The transmission brake is an essential safety feature that contributes to the overall control and security of a vehicle when it's parked. It complements the parking brake, which is typically applied to the rear wheels, and provides additional assurance that the vehicle will not roll or move unintentionally.
