Vibration when turning on the automatic transmission can be caused by several reasons:
*Low or poor quality transmission fluid: Low or dirty fluid can cause insufficient lubrication of transmission components, causing vibration.
* Malfunctioning or worn torque converter: The torque converter transfers power from the engine to the transmission. A faulty or worn torque converter can cause vibration due to imbalance or slippage.
* Transmission control module (TCM) malfunction: The TCM controls the operation of the transmission. A faulty TCM may shift gears incorrectly or cause other problems that lead to vibration.
* Worn or damaged engine or transmission mounts: Engine and transmission mounts are designed to absorb vibrations. Worn, damaged or broken mounts can cause vibration to be transmitted into the body of the vehicle.
* Warped driveshaft: The driveshaft transfers power from the transmission to the rear wheels. A warped or unbalanced driveshaft can cause vibration.
* Malfunctioning exhaust system: An improperly installed or damaged exhaust system can resonate with the vehicle’s body and cause vibration.
* Increased differential play: The differential distributes power between the drive wheels. Increased play in the differential can lead to vibrations, especially when accelerating or cornering.