How Many Times Should the Transmission Oil Be Changed After Water Ingress?
2 Answers
Transmission water ingress requires at least 2 oil changes, while a thorough cleaning may require up to 5 oil changes. Handling transmission water ingress: Once water enters the transmission, it must be sent to a specialized transmission repair facility for a circulating oil change within 24 hours. If more than 24 hours have passed but within 48 hours, disassembly and cleaning are necessary. Continued use under such conditions, combined with gear agitation and high-temperature, high-pressure environments, will cause water-oil mixing, leading to the loss of oil film protection for internal transmission components. Precautions for oil changes: Avoid using inferior transmission oil, as low-quality or counterfeit transmission oil has poor temperature resistance, is prone to oxidation, and can cause sludge and residue buildup, clogging filters and reducing transmission oil pressure. It is essential to visit a professional automatic transmission repair company to completely replace and remove the automatic transmission fluid and other contaminants.
That time I dealt with a car with a water-damaged transmission. Water mixing with oil can cause parts to rust and fail, so a single oil change definitely isn't enough. Typically, you need to change the oil two or three times. For example, first drain the old oil and add new oil, start the car and let the engine run for about ten minutes. The hot oil will evaporate the moisture and absorb residual impurities, then drain it and replace it with new oil. Repeat this cycle to ensure thorough cleaning, with a drive of several dozen kilometers between each change. If the water damage is severe, like in a flood-damaged vehicle, you might need more than three changes to feel safe. I recommend going to a professional repair shop quickly to check the transmission's water content—don't DIY it to avoid missing details. Prevention? Avoid deep water areas and regularly maintain the transmission fluid level. If you notice any gear shifting issues, early inspection can save you a lot of money—safety first.
