Will Water Enter the Transmission When Driving Through Water?
3 Answers
Yes. Generally, transmission water ingress is mainly caused by the following two situations: Situation 1: Water level exceeds 2/3 of the wheel height. The first scenario is when the car is submerged in water. The specific criterion is that if the water level exceeds 2/3 of the wheel height, the probability of water entering the transmission is around 80% to 90%. If the water has already reached the dashboard level, the transmission is 100% flooded. Situation 2: Water splash enters the transmission during oncoming traffic. The second scenario occurs during oncoming traffic when there is excessive standing water on the road. The splashing waves hitting the car body can also cause water to enter the transmission. When water enters the transmission, the performance of the transmission fluid will be severely affected. Not only will the lubrication performance be compromised, but the power transmission capability of the fluid will also decline, leading to clutch slippage and subsequent oil temperature rise. This can also result in the generation of water vapor or even boiling of the oil-water mixture. These viscous substances can accumulate in the valve body, causing blockages and affecting the transmission control system. After driving through water, if you notice that the car does not move when shifting gears or experiences abnormal vibrations during acceleration, Xin Dongli recommends that drivers contact a repair shop as soon as possible for inspection to avoid further damage.
Last time I drove through deep water, I learned the hard way that transmissions can indeed take in water! There's a vent tube at the bottom of the transmission, just like we need to breathe. If the water level rises above half the tire height, water can flow back into the transmission through the vent tube. After crossing the water, my gears made grinding noises when shifting, and the repair shop found the oil had emulsified and turned white. The mechanic said automatic transmissions are more delicate, with many precision components inside, and water can corrode the gears and solenoid valves. The worst part is that there are no obvious symptoms in the early stages of water ingress—by the time you notice jerking or slipping, the repair bill could easily reach four figures. Now I avoid puddles altogether, even if it means detouring an extra two kilometers. Actually, the vehicle manual specifies the maximum wading depth, which is far more reliable than our rough estimates.
I've been repairing transmissions for over a decade and have seen countless water intrusion cases. A transmission isn't a sealed can - its Achilles' heel is the vent hole on top. When wading depth exceeds the wheel hub centerline, water rushes in through the tubing. Water damage occurs in two phases: first contaminating transmission fluid to cause lubrication failure, making gears grind dry and overheat; then corroding valve bodies and circuit boards. I once serviced a flood-damaged car - opening the transmission revealed rusted bearings and emulsified sludge. The repair bill for replacing seals, cleaning valve bodies, and changing bearings totaled over 8,000 yuan, enough for two new tires! Prevention is simple: avoid deep water in rain, and maintain steady throttle without shifting when crossing water.
