What are the effects of not changing transmission fluid for a long time?
2 Answers
Here are the effects of not changing transmission fluid for a long time: 1. Gear corrosion: The pH value of the transmission fluid will change, causing corrosion to the gears inside the transmission. 2. Deterioration of lubrication: Transmission fluid continuously decomposes with use and time. If not replaced, its viscosity and lubricity will continuously decline and adhere to critical components. Friction from contaminated fluid can cause metal particles floating in the oil to continuously scratch bearings, races, gears, and other components, potentially leading to transmission shaking, inability to shift, misalignment, or even gear and bearing breakage. 3. Internal transmission blockage: Various contaminants can form inside the transmission, and combined with metal particles, they can clog the transmission, check valves, and filters, leading to abnormal internal pressure. Automatic transmissions require precise pressure for operation, and abnormal pressure can cause transmission seal failure; manual transmissions may experience shifting failure or gear misalignment if clogged. 4. Transmission overheating: Besides lubrication, transmission fluid also cools the transmission. Prolonged failure to replace old fluid can cause the transmission to overheat continuously. This heat weakens the viscosity and lubricity of the transmission fluid, generating additional friction.
My old car hasn't had its transmission fluid changed in seven or eight years. Recently, I noticed the gear shifts were particularly sluggish, and the car shook violently during acceleration. When I took it to the shop, the transmission was full of sludge. The mechanic said that long-term failure to change the fluid allows impurities to accumulate, clogging small passages, leading to insufficient lubrication and increased gear wear. This makes gear shifts noticeably less smooth, and rising temperatures can easily cause overheating. Ultimately, it may result in internal seal failure or torque converter damage, and in severe cases, the entire transmission could be ruined, with repair costs running into thousands. I regret it deeply. Now, I follow the manual and change the fluid every 30,000 to 50,000 kilometers to prevent small issues from turning into big troubles, and it also helps improve fuel efficiency.
