How Does Water Enter the Transmission?
2 Answers
During the summer, there is more rainfall, vehicles frequently wade through water, and the frequency of car washes increases. Additionally, air conditioning is often used for cooling, which can lead to water entering the automatic transmission. Carelessness may result in automatic transmission failure. Depending on the extent of water ingress, the repair costs will vary. Relevant information is as follows: Transmission Oil Deterioration: Water entering the automatic transmission directly causes the transmission oil to deteriorate and oxidize, thereby reducing its friction coefficient. This leads to insufficient friction between vehicle components, resulting in symptoms such as jerking, impact, and slipping in the automatic transmission. For very minor cases, only changing the automatic transmission oil and seals may be required. However, if some electrical components are also exposed to water, the cost will increase. Timely Repair: The earlier the vehicle is repaired after water ingress, the lower the cost will be. If the automatic transmission has minor water ingress and is not repaired promptly, it may lead to a series of issues over time, such as oil leaks, abnormal noises, and "jerking" symptoms. By then, the repair costs for the automatic transmission could be 3-5 times higher than before.
The story of how water got into my car's transmission is a long one. There was a heavy rainstorm one time, and the road was flooded with deep water. I thought driving through slowly would be fine, but the water level ended up exceeding the transmission's vent hole, allowing water to seep directly inside. The transmission isn't completely sealed—its vent hole is located at the bottom or on the side. If the water level is too high or the car gets submerged, water can pour in. Later, when I checked the fluid and found it had turned milky white, I realized something was seriously wrong. Water in the transmission mixes with the oil, causing lubrication to fail, and internal components like gears and bearings can rust and corrode. The repair ended up costing me several thousand dollars. Since then, I never take risks when encountering heavy rain or deep puddles. Now, I regularly check the vent hole's condition and try to avoid driving through deep water—I really don’t want to go through that kind of repair hassle again.
