What Causes the Car to Roll Backward When Parked in First Gear?

[Jimenez]

Because the slope is too steep, the power provided by first gear is insufficient. Here are the relevant explanations: 1. Specific principle: Although the car is in gear, if the handbrake is not engaged, the friction from the cylinder piston, clutch, and gears may be less than the downward pulling force of the vehicle parked on a slope. Always remember to engage the handbrake for any vehicle; without the handbrake, you should both shift into gear and park on a flat road. 2. Details of rolling: If the slope is steep and the car is heavy, being in gear may not be enough to hold the car. The car rolls forward because the downward gravitational force converts into power, pulling the car downward. The jerking motion occurs because the engine provides resistance when in gear, and the engine piston's movement creates the greatest resistance at the highest and lowest points, causing a jerk before rolling, then another jerk at the highest and lowest points, followed by more rolling.