Does stalling in D gear damage the car?
3 Answers
Stalling in D gear can indeed harm an automatic transmission vehicle, particularly damaging the transmission. The correct procedure is: press the brake, shift from D to N after stopping, turn off the engine, then shift from N to P, and finally release the brake. D gear is the drive gear used while the car is moving. Most automatic vehicles have D gear designed with a sequence from 1st to higher gears, or sometimes 2nd to higher gears. When driving, placing the gear lever in D allows the vehicle's speed to be controlled by the accelerator. An automatic transmission eliminates the need for manual gear changes by the driver, as the vehicle automatically selects the appropriate gear based on speed and traffic conditions. Automatic cars typically have six gear positions, arranged from top to bottom as: P, R, N, D, S, L.
I've been driving for decades, and this situation is indeed rare in automatic transmission cars. However, if the engine stalls while in D gear, it might affect the vehicle. Specifically, the engine suddenly stops, but the transmission remains engaged, meaning the hydraulic pump isn't running, leading to insufficient gear oil pressure. This could cause internal wear, such as additional stress on the torque converter or planetary gear set. If this happens frequently over time, the transmission might age prematurely or even get damaged. I've experienced it twice myself, noticing severe shaking, and upon inspection, minor scratches were found. The key is to develop good habits: it's best to shift to N or P gear before turning off the engine to avoid accidents. An occasional occurrence isn't a big deal, but if it happens often, you should investigate the cause, which could be low engine idle or sensor issues.
As someone who frequently researches cars, I believe that stalling in Drive (D) gear is highly unlikely under normal driving conditions, as modern vehicles are equipped with safety systems to prevent stalling. However, if it does occur—such as due to unstable idling or a malfunction—where the engine stops running while still in D gear, it can cause impact to the transmission. The reason is that the transmission relies on the engine's operation to provide hydraulic pressure for lubrication and gear shifting. Once the engine stops, insufficient oil film between the clutch plates and gears may lead to increased friction or even deformation. Having modified transmissions for several cars, I've observed a few cases where such stalling accelerated component wear. My advice is to restart the engine immediately after stalling. If it happens repeatedly, check the mass airflow sensor or fuel pump. Regular transmission fluid changes during maintenance can help prevent this issue.
