* Transmission issues: This is the most likely culprit. The torque converter, responsible for smooth power transfer between the engine and transmission, might be wearing out or malfunctioning. As the car slows, the converter's clutch engagement can become erratic, leading to a jerk. Problems with the valve body controlling fluid flow within the transmission can also cause this.
* Engine mounts: Worn or damaged engine mounts allow the engine to move excessively. As the engine slows, this movement can cause a sudden shift in torque delivery, resulting in a jerk.
* Low transmission fluid: Insufficient transmission fluid reduces lubrication and pressure, leading to rough shifting and jerky stops.
* Brake system issues: While less likely to cause a jerk *right* before the complete stop, severely worn or malfunctioning brakes could contribute to a jerky sensation. The car might be struggling to smoothly decelerate, leading to an abrupt stop.
* Software glitches (in newer cars): Modern cars have sophisticated computer systems managing the transmission. A software glitch could cause erratic behavior in the transmission's control system.
* Driver error (less likely): Rapidly releasing the accelerator pedal just before stopping can sometimes cause a slight jerk depending on the car's settings and transmission behavior.
Troubleshooting:
If this jerking is consistent, it's crucial to get your car checked by a mechanic. They can diagnose the problem accurately and recommend the appropriate repairs. Ignoring the issue could lead to more significant transmission problems down the line. Describing the jerk precisely to the mechanic (e.g., "it happens only when slowing down completely," "it's a forward jerk," etc.) will help them pinpoint the cause.
