What are the effects of overfilling transmission fluid?
2 Answers
The effects of overfilling transmission fluid are: 1. Excessive air entering the transmission, causing clogging of the drain holes on the control valve, resulting in poor drainage and gear shift impact; 2. When the fluid level contacts rotating components, bubbles may form. When bubbly oil enters the oil pump, it leads to abnormal oil pressure and affects lubrication effectiveness. Transmission fluids can be categorized by transmission type: 1. Automatic transmission fluid (ATF); 2. Manual transmission fluid. Transmission fluid is a lubricant that maintains cleanliness in the gear system, ensuring proper transmission operation and prolonging the lifespan of transmission components. It provides effective lubrication at low temperatures and reduces fluid loss under severe operating conditions.
Just a couple of days ago, I helped my neighbor check their car because the transmission fluid was overfilled, resulting in clunking noises when shifting gears. Overfilling can cause the fluid level to be too high, making it easy for foam to form when the gears churn. This foam can disrupt lubrication, and the hydraulic system may malfunction due to abnormal pressure. The most obvious symptom is oil leakage—the seals simply can't handle that kind of high pressure, leaving oil stains on the floor and transmission housing in no time. The gear shifts feel extremely jerky, like being kicked from behind. Once, I opened it up and saw the clutch plates slipping because they were soaked in oil, and the steel belt might also be worn. Running it like this for too long can be very costly, so it's best to drain the excess fluid ASAP and definitely avoid driving it hard.
