Why Does the Transmission Get Water Inside?
4 Answers
Transmission can get water inside because it has ventilation holes, which may form small water droplets due to temperature changes. These droplets vaporize under high temperatures and are expelled as steam. Below is an introduction to water ingress in transmissions: 1. Precautions: When water enters the transmission, the performance of the transmission oil is severely affected—not only is its lubrication performance compromised, but its power transmission capability also declines. This can lead to clutch slippage, followed by an increase in oil temperature, which may generate steam or even cause the oil-water mixture to boil. These viscous substances can accumulate in the valve body, causing blockages and affecting the transmission control system. 2. Explanation: Severe water ingress requires replacement of related components: Rubber components such as gaskets and seals need to be replaced; friction plates must be replaced because they consist of steel plates and high-density wood materials, which swell when exposed to water, affecting friction performance. Additionally, the transmission oil and differential oil must be completely replaced.
I have repaired multiple cases of water ingress in transmissions, which typically stem from several key reasons. The transmission has sealing components, such as oil seals, which can age or become damaged over time, allowing water to seep inside when driving through accumulated rainwater. Additionally, blocked or poorly designed vent holes can cause water to backflow when water levels rise. I've also seen cases where external water pressure forces water into cracks or weak sealing points in the transmission housing when the vehicle wades through deep water. Once water enters, the transmission fluid emulsifies and loses its lubricating ability, leading to gear rusting, bearing wear, and in severe cases, the entire transmission being scrapped, with repair costs being alarmingly high. Therefore, I advise vehicle owners to regularly inspect the sealing condition, especially replacing old oil seals before the rainy season, and to avoid driving through excessively deep water. Water ingress may seem like a minor issue, but if not addressed promptly, it can lead to major disasters. Remember, prevention is better than repair.
I learned from my own car troubles that transmission water ingress is often caused by poorly protected vents or failed seals. That time I drove through floodwater during a heavy rainstorm, water seeped in through the vent, contaminating the transmission fluid and turning it milky white. Delayed oil change led to gear wear. Another common cause is aged or cracked external seals allowing rainwater or pressure wash water to enter. From experience, performance deteriorates after water ingress - gear shifts become jerky or even stall. I've since made it a habit to check seals and change fluid every six months. This is a safety issue - don't wait for problems to act. Simple maintenance prevents costly repairs. Daily driving requires attention to water depth - avoid forcing through deep water to significantly reduce flooding risks.
The main causes of water ingress in transmissions include seal damage and ventilation system defects. Worn-out sealing components allow external water to easily penetrate. Poorly designed or clogged vent holes can cause water backflow during wading, damaging the lubricating oil. After water ingress, the oil-water mixture emulsifies, leading to lubrication failure, gear rusting, or sintering. I recommend timely inspection and oil changes to maintain proper functioning.
