Will the Transmission of a Flooded Car Get Water Inside?
4 Answers
Flooded car transmissions can indeed get water inside. Here is the relevant information: 1. First scenario: Engine coolant enters the automatic transmission through the radiator. 2. Second scenario: After the vehicle is flooded, water enters through the automatic transmission vent. 3. Hazards: When water enters the automatic transmission, vehicle faults do not appear immediately, so owners often overlook checking the transmission fluid. Over time, the transmission fluid deteriorates and emulsifies, leading to reduced lubrication performance and increased wear of internal components. When the transmission slips, the fluid turns black and emits a burnt smell, and the friction elements of the clutch and brake slip. This phenomenon can cause the engine to rev high while the vehicle speed increases slowly, often affecting gear shifting as well. At this point, the transmission must undergo major repairs.
I'm a mechanic, and transmissions can indeed get water inside, especially in flooded cars. There are vent holes on the transmission casing, and if the water level rises, water can seep in through these holes, mixing with the gear oil and turning it milky white, like milk. If you try to start and drive the car after it's been submerged, the water will mix with the oil and churn inside the gears, causing the transmission to rust and seize up. The repair cost could be as much as half the price of a used car. Last time, Old Zhang next door had his car flooded—he didn’t want to spend money on repairs, drove it for two months, and the transmission completely failed. In the end, he had to tow it to our shop to salvage parts. So remember, the first thing to do after your car is flooded is to call a tow truck—never start the engine.
My car was flooded during last year's heavy rain, with water just reaching the wheel hubs. When I took it to the 4S shop for inspection, the mechanic said the transmission fluid had turned white. They explained that there are sealing gaskets and vent holes at the bottom of the transmission. If the water pressure is high enough, like in a flood situation, even a brand-new car can't withstand it. The most troublesome part is that a water-damaged transmission is prone to aftereffects even after repair. Now, my car occasionally grinds when shifting into reverse. It's recommended to have flood-damaged vehicles thoroughly inspected by professional institutions, especially automatic transmission models. The cost of repairing a transmission could be enough to buy two sets of tires.
The transmission in automotive design is not completely sealed; its vent is typically positioned above the chassis but below the engine compartment. When a vehicle is fully submerged, water pressure can force water into the transmission housing. The ingress of water reduces lubrication and causes internal metal oxidation. I have encountered cases where owners ignored warnings, leading to complete transmission failure. During repairs, it is necessary to disassemble and clean all gear sets and replace contaminated fluids. Even after repair, the lifespan of the transmission is reduced by approximately 30%.
