Mechanical reasons:
* Worn or faulty friction discs: Over time, friction discs can wear out or become damaged due to heat and friction, causing transmission slippage and jerking.
* Faulty Transmission Control Solenoids: The solenoids control the flow of transmission fluid through the valve plate, which operates the various gears. Faulty solenoids can cause inaccurate gear activation and jerking.
* Insufficient transmission fluid level: Low transmission fluid levels can cause insufficient lubrication and air bubbles, resulting in shifting shocks.
* Worn Oil Filter: A dirty or clogged oil filter can restrict transmission fluid flow and cause hesitation.
* Faulty torque converter: The torque converter links the engine to the transmission and serves to dampen torque. A faulty torque converter can cause vibrations and shocks to be transmitted to the transmission.
Electrical reasons:
* Faulty Transmission Position (TPP) Sensor: The TPP tells the transmission control module (PCM) the position of the gear shift, which allows the PCM to properly control the gear shift. A faulty TPP can cause improper shifting and jerking.
* Faulty PCM: The PCM controls the transmission by receiving input from sensors and controlling solenoids and other transmission components. A faulty PCM may not properly control gear shifts, resulting in jerking.
* Faulty Wiring: Damaged or faulty wiring can interfere with the transmission of electrical signals between the PCM and transmission components, resulting in improper shifting and jerking.
Other possible reasons:
* Worn or damaged engine and transmission mounts: Worn or damaged mounts can cause excessive vibration from the engine and transmission, which is transmitted to the vehicle body and causes vibrations.
* Faulty torque converter lock-up clutch: The torque converter lock-up clutch locks up the torque converter at certain speeds, improving efficiency. A faulty torque converter lock-up clutch can create a jerk when turning on and off.