Why does the car shake when shifting into P gear for parking?
4 Answers
When the vehicle is parked on a slope and shifted into P gear, it may shake back and forth slightly. In fact, this does not cause damage to the transmission. This occurs because there is a gap between the parking pawl and the parking gear. Due to the mechanical imprecision of the parking pawl, the vehicle may shake slightly back and forth after shifting into P gear and releasing the foot brake. Once the parking pawl engages fully, the vehicle will no longer move. Here is the relevant explanation: The P gear in automatic transmission vehicles is the parking gear, which is essentially an evolution of the N gear. In addition to placing the transmission in neutral mode, the P gear also includes a parking pawl inside the transmission and a parking gear on the power output shaft. When shifted into P gear, the parking pawl and parking gear inside the transmission interlock, thereby fixing the vehicle in place.
After driving for so many years, I've noticed that a slight shake when shifting into P (Park) is quite common. It usually happens because the vehicle isn't completely stopped before shifting gears. Automatic transmissions have a component called the parking pawl, which needs to engage properly. If the car is still slightly moving, it can cause a small vibration as the gears suddenly lock into place. This is more noticeable when parking on a slope, as gravity can cause the car to shift slightly, triggering the mechanism. While it's not a major issue, it could lead to component wear over time and isn't good for the transmission in the long run. I recommend firmly pressing the brake and waiting until the car is fully stopped before shifting into P, especially on inclines where using the parking brake can help reduce the shake. Developing good habits like this can help extend your car's lifespan.
I often drive a Hyundai automatic transmission car, and it's quite common for the car to jolt slightly when shifting into P (Park) occasionally. This is related to the internal design of the transmission. When you engage P, the parking pawl locks onto the output shaft to secure the wheels. If the ground is uneven or the car is still moving slightly during the shift, the meshing process of mechanical components can cause a bit of impact. I've experienced this a few times with new cars, and technicians have told me it's normal. However, frequent occurrences could signal aging transmission fluid or loose components. My advice is to ensure the car comes to a complete stop before shifting into P—especially at red lights—to protect the vehicle from potential damage. A little extra care in maintenance goes a long way.
Many car owners mention this issue during repairs. The main reason for shaking when shifting into P is the parking pawl mechanism engaging—it's like a small claw grabbing into gear teeth gaps. If you park on a slope without using the handbrake, gravity pulls the car causing slight movement, resulting in noticeable vibration when the mechanism forcibly engages. This is common in older vehicles due to part wear or torque converter issues. Having handled similar cases, I recommend stabilizing the car with the handbrake before shifting to P to reduce impact. Regular transmission fluid checks also help prevent this.
