Handbrake before park: Avoiding transmission lock and damage on inclines

Using an automatic transmission is much simpler than a manual one, but some situations can surprise us. One such case is leaving the vehicle in P position, which can later prevent it from moving.

The P position, which means parking, is a setting of the automatic transmission lever that locks the gearbox. It is only used after the ride is completed and before the engine is turned off.

User manuals and various guides emphasize that leaving the car in P on an incline should be preceded by engaging the parking brake. Otherwise, the element that locks the gearbox can be damaged by the large forces acting on it.

This is partially true, although cases of locking mechanism damage in automatic transmissions are extremely rare and mainly result from extreme situations.

– In everyday use, this is almost impossible – explains mechanic Marcin Albricht Wiśniewski from Chester & Wasyl Garage, where mainly cars with automatic transmissions are serviced. "I have encountered such a problem only once, in exceptionally extreme conditions," he adds.

So, what can happen? An overloaded lock can cause the transmission lever to jam. After starting the engine, moving it from P to R or another position might be difficult, but not impossible. It may require more force.

It's worse when the car is equipped with an electronic lever, which is just a manipulator giving commands to the controller.

– In the case of an electronic selector and a significant road incline, it may turn out that the gearbox does not come out of P – the mechanic warns. "In that case, the car will not move, and you will need to help it by 'discharging' the stresses by gently pulling the car towards the incline or lifting the driven axle," he specifies.

Unfortunately, the vast majority of cars nowadays already have electronic levers. When pushing or pulling the vehicle, you need to be especially careful because pushing too hard in the opposite direction can cause stress, or even destroy the transmission.

Drivers with automatic transmissions often forego using the parking brake. On flat surfaces, this is not an issue, but on inclines, it is a mistake.

After stopping the vehicle, with your foot on the brake pedal, you should first engage the handbrake, then move the automatic lever to the N position, take your foot off the brake, and allow the parking brake to engage. Only after all this can you switch the transmission to the P position.

Using the P position is crucial when the car is stationary. Engaging parking while the vehicle is still slightly rolling can lead to failure, such as damage to the locking mechanism. This is more likely than in cases of parking on an incline.