Fuel tank sloshing and clunking noise underneath the driver and passenger seats. the vehicle fuel tank design locates a portion of the gas tank under the vehicle and below the seats. when the gas tank is above half full, you can hear and feel the gas moving in the tank, especially at low speed, during traffic with frequent stopping. not sure how safe is to feel the gas moving inside the fuel tank and the noise when the gas impacts the gas tank walls. when the tank is full and you brake, the fuel sloshes forward and moves something inside and slams against the inside of the tank.
The explorer was put into reverse. the vehicle drove forward about 3 ft, jerked, then slammed into reverse. reaction time on my behalf was slow as it was unexpected, i almost hit a light pole. this occurred in a parking lot
During low speed maneuvers like parking and when coming to a stop, the fuel sloshes loudly and can be heard inside the vehicle. it sloshes most noticeably when the fuel level is above 3/4 full. the fuel moves so much it sometimes sounds like there's something hitting the floor underneath the driver seat or a driveline issue.