What Happens If Automatic Transmission Fluid Is Not Changed for a Long Time?
3 Answers
Due to the specific operating environment inside the transmission, transmission fluid has a certain shelf life. If not changed for a long time, the performance of the fluid will deteriorate, generating more impurities, which can lead to accelerated wear of transmission components, earlier occurrence of failures, or higher failure rates. Below are the relevant details: 1. Function of Transmission Fluid: The main role of transmission fluid is to keep the shifting system clean and to lubricate the transmission components, thereby extending their lifespan. 2. Replacement Interval: Generally, automatic transmission fluid (ATF) should be replaced every two years or every 40,000 kilometers. Manual transmission fluid can usually be replaced at 60,000 kilometers, but this depends on the vehicle model. Vehicles that frequently drive at high speeds are advised to undergo maintenance earlier at a repair shop.
When I first bought my car, I thought automatic transmission fluid didn’t need frequent changes—why not save a bit where I could? But then trouble struck. Over time, the fluid degraded and became as thick as asphalt, drastically reducing its lubrication effectiveness. Inside the transmission, gears and clutch plates were grinding against each other, causing severe wear. After driving for over two years without a fluid change, the car started jerking during gear shifts, especially in stop-and-go traffic, leaving me on edge. The mechanic said sludge buildup had clogged the hydraulic channels, leading to rough shifting and overheating, nearly frying the entire transmission. The repair cost me over 3,000 yuan—had I checked and changed the fluid earlier, a routine maintenance of just a few hundred yuan could’ve prevented it. Now, I make sure to change it every 40,000 kilometers—safe and cost-effective. Don’t repeat my laziness.
From years of driving experience, neglecting automatic transmission fluid changes poses significant risks. As the fluid ages, its viscosity decreases or thickens, losing its cooling and lubricating properties, which can lead to overheating and wear of valves and clutch components. My neighbor's car, which hadn't had its fluid changed for five years, suddenly failed to shift gears while driving, nearly causing an accident on the highway. Upon inspection, metal shavings and sludge were found in the fluid, reducing system efficiency and increasing noise. It's generally recommended to change the fluid around 50,000 kilometers, but more frequent changes are needed for short trips or heavy loads. Small maintenance extends mechanical life, while major repairs can drain your wallet. Proper maintenance ensures your car runs smoothly and lasts longer.
