What to Do If Too Much Transmission Fluid Is Added?
2 Answers
It is recommended to drain some if too much transmission fluid is added. This is because the lubrication at the crankshaft relies on the oil being stirred by its own rotation, so the oil level should not be too high. Otherwise, the stirring resistance increases, and excessive oil splashing onto the piston area may lead to increased oil leakage. Here are some related details: 1. Transmissions can be divided into automatic and manual, and the frequency of fluid changes varies accordingly. Problems can arise if the transmission fluid is not changed for a long time. Transmission fluid working under high-speed and high-temperature conditions for extended periods can deteriorate and evaporate, thereby accelerating the wear of mechanical parts and, in severe cases, damaging internal transmission components. 2. Without changing the transmission fluid, the vehicle may experience weak starts when cold. During driving, slight slipping and similar phenomena may occur. Long-term neglect of transmission fluid changes can cause the fluid to thicken, potentially obstructing the transmission cooler and leading to excessively high fluid temperatures, which exacerbates wear. 3. The primary function of transmission fluid is to keep the shifting system clean and to lubricate and prolong the life of the transmission components. Due to differences in transmission design—manual transmissions and automatic transmissions (further categorized into CVT, AMT, etc.)—each transmission type has specific technical requirements. Even the same transmission model used in different vehicles may vary in torque, weight, speed, and structure, which is why manufacturers specify their own dedicated transmission fluids.
Last time I overfilled the transmission fluid a bit, and the car started shifting noticeably rough with strange noises. I immediately stopped to check and found that excessive fluid can cause foaming, reducing lubrication effectiveness while increasing pressure and potentially causing leaks. As a DIY car enthusiast, I used a syringe to slowly extract the excess fluid through the dipstick tube—removing a little at a time and checking the level repeatedly to keep it between the two marks on the dipstick. It's best to do this with the engine running and the transmission warm for accurate measurement. After removing the excess, I test-drove the car, and the shifting returned to smooth operation. Now I carefully follow the manual's specified quantity when adding fluids to avoid mistakes. Experience has taught me that prevention is better than cure, and regularly checking fluid quality is also crucial to avoid unnecessary repair costs.
