What are the symptoms of overfilling AT transmission fluid?
1 Answers
Overfilling transmission fluid can cause gear shift shocks, automatic transmission fluid leakage, and reduce the cooling function and transmission efficiency of the gearbox. Automatic transmission fluid leakage: If the transmission fluid level is too high, the rotating components will come into contact with the fluid during driving. Under the agitation of high-speed rotating components such as planetary gear mechanisms or clutches, the fluid will expand and boil, causing it to spurt out from the filler hole and vent valve. Since the transmission is located right above the exhaust pipe, fluid dripping onto the exhaust pipe during driving will result in black smoke emerging from the car's skirt, making it appear as if the car is on fire. Reduced cooling function and transmission efficiency: The main functions of transmission fluid are lubrication and cooling. The fluid transfers heat through the transmission housing and transmission cooler. If too much fluid is added, the rotation of gears will encounter greater resistance, reducing the cooling function and transmission efficiency. This requires the engine to consume more fuel, decreasing the vehicle's overall fuel economy. Moreover, this energy loss will be converted into heat inside the transmission, causing the transmission temperature to continuously rise. Ultimately, this leads to premature wear of the bearings and burning of the friction plates inside the transmission. Both replacement and repair are costly. In summary, the fluid level should neither be too high nor too low. During the design phase of the transmission, lubrication and temperature rise tests are conducted, and the fluid level is precisely verified.
