How Long Does It Take for an Automatic Transmission to Fail After Water Intrusion?
3 Answers
Transmission failure symptoms do not appear immediately after water intrusion but gradually manifest within two weeks. Water entering the transmission can cause internal components to rust and degrade the transmission fluid. If the friction plates absorb water, they cannot be repaired and must be replaced along with other sealing components, increasing repair costs. Symptoms of water in the transmission include: 1. Minor water intrusion: Some screws inside the transmission may rust. It is advisable to replace gaskets, oil seals, and other components to extend service life, along with replacing the transmission fluid and differential oil. 2. Moderate water intrusion: White deposits appear in the oil pan. When oil mixes with water, it forms a white emulsion that adheres to the oil pan. The presence of such deposits indicates moderate water intrusion. Gaskets, oil seals, transmission fluid, and differential oil must be completely replaced. 3. Severe water intrusion: The color and viscosity of the transmission fluid can indicate severe water damage. Water in an automatic transmission can corrode steel screws inside the transmission, necessitating prompt inspection and repair. Similar to moderate intrusion, severe cases may also require replacing the sprocket.
The other day my car drove through a flooded pothole and the transmission got waterlogged, but I stubbornly kept driving for ten days. Surprisingly, it ran normally for the first couple of days, just with slightly stiff gear shifting. Then on the third day while on the highway, it suddenly started jerking during gear changes, and the dashboard lit up with warning lights like a Christmas tree. Once water gets in there, the lubricant emulsifies faster than spoiled milk, and the metal components start rusting inside. The only reason it didn’t break down immediately was that the water didn’t fully penetrate, but gear corrosion and solenoid rust-through will catch up eventually. My advice—don’t push your luck, drain the fluid and get it checked ASAP.
Last month during a heavy rainstorm, my car drove through deep water, and that night I heard a buzzing noise from the transmission. The next day, when I shifted to D gear, the engine revved but the car wouldn't move. After towing it to the repair shop and opening it up, they found the clutch plates rusted like scrap metal. The mechanic said waterlogged bearings would definitely develop rust spots, and the transmission could fail within as little as two or three days, or up to half a month at most. Especially for newer transmissions with electronic valves, water damage can cause instant failure. If you discover water ingress, immediately disconnect the battery and call a tow truck to avoid repair costs that could amount to half the price of a new car.
