What Causes the Jerking When Shifting to D Gear in an AT Transmission?
1 Answers
Reasons for jerking and shaking when shifting to D gear in an AT transmission: engine speed too high, brake not pressed firmly, or brake released too early. Engine speed too high: When the engine speed is too high during a cold start, the torque converter transmits more power, resulting in greater impact force and more noticeable shaking when shifting gears. The only correct and safe method when going downhill is to use engine braking to control speed and reduce the frequency of brake usage. Brake not pressed firmly: At the moment of shifting, engine power is directly transmitted to the wheels. If the brake is not pressed firmly, the wheels may slightly move when shifting to D gear, causing the vehicle to suddenly move forward with a stronger shaking sensation. Solution: Press the brake firmly to ensure the wheels do not move slightly. Brake released too early: Releasing the brake too early causes abrupt power engagement. The automatic transmission lever does not directly control the gear position; it is merely a signal device. Different signals are sent to the transmission control system when shifting to different gears, which then controls the gear shift. However, the transmission requires some time to complete the shift. Thus, at the moment of shifting to D gear, the transmission gears are not yet engaged. After releasing the brake, when the gears engage, the driving wheels suddenly receive power without the restriction of the brake, causing the vehicle to move forward abruptly and resulting in shaking.