When you put a vehicle in park, you expect it to stay put. That expectation not living up to reality is the reason for Ford's latest recall.
Ford has issued a recall for approximately 52,000 examples of the 2017 F-250 pickup truck. Every affected truck carries a build date between Oct. 9, 2015 and March 30, 2017. 48,421 of those trucks are in the US, with the remainder living up in Canada.
As one might expect, the problem lies with the transmission. The park rod actuating plate might be damaged, which means the transmission might not actually put itself in park, despite the gear selector's position.
When it comes to placing a vehicle in park, it all comes down to the pawl. When the shifter moves to P, it engages a pin that moves into place, locking the transmission's output shaft and preventing it from moving. That rock-back movement you occasionally feel after putting a car in park is the transmission bouncing off that pawl.
So, instead of being in park, the truck might actually be in neutral. If the parking brake is not applied, the truck may experience unintended movement, even if it's parked on seemingly flat ground. The parking pawl and parking brake operate independently of one another, so Ford recommends using the parking brake every time the vehicle is put in park, in order to prevent any accidental movement.
In order to remedy the issue, dealership employees will have to inspect the park rod actuating plate in the transmission. If it's damaged, the dealership will replace it. It's unclear when the recall will begin, or if dealers already have the replacement parts in question.