What is the working principle of transmission fluid?
3 Answers
The working principle of the transmission is to assemble two turbine blades in a space filled with hydraulic fluid, which are connected to the power input end and the power output end respectively. The powerful vortex generated by the impeller at the power input end drives the impeller at the output end, thereby achieving power transmission. The functions of the transmission: Change the transmission ratio to expand the range of torque and speed variation of the driving wheels; enable the vehicle to reverse while the engine rotation direction remains unchanged. The transmission, also known as the gearbox, is a mechanism used to alter the speed and torque from the engine, capable of fixing or changing the transmission ratio between the output shaft and the input shaft in steps. Classification of transmissions: Step-type transmissions use gear transmission and have several fixed transmission ratios; continuously variable transmissions can continuously obtain any transmission ratio within the speed range; integrated transmissions refer to hydromechanical transmissions composed of a torque converter and a stepped gear transmission.
I've always considered transmission fluid as the lubricating companion of a vehicle. Its primary role is to lubricate all moving components inside the transmission during operation, such as gears, bearings, and clutch plates, reducing friction and wear between them and preventing damage caused by overheating. In automatic transmissions, the fluid also serves a hydraulic function, utilizing fluid pressure to control the gear-shifting process, ensuring smooth and seamless transitions between gears. Manual transmissions, on the other hand, focus more on straightforward lubrication. If the fluid isn't replaced periodically, it can oxidize, thicken, and accumulate contaminants, leading to transmission slippage, increased noise, or complete failure. Once, my car had rough shifting issues, and I discovered it was due to old fluid—after replacement, it ran smoothly again. It's recommended to change the fluid every 60,000 kilometers, but always refer to the vehicle's manual for specifics, as improper maintenance can lead to costly repairs. Choosing the correct type of fluid is also crucial: automatics typically require specialized ATF (Automatic Transmission Fluid), while manuals use regular oil with matching viscosity to ensure long-term reliability.
Having worked in auto repair shops for years, I've gained a clear understanding of how transmission fluid works. It's essentially a lubricant that coats internal gears, shafts, and components with a protective film, reducing friction heat and preventing wear or deformation from high temperatures. In automatic transmissions, the fluid also serves as hydraulic oil - the pump creates pressure to actuate valves for gear shifting, ensuring smoother driving. Dirty fluid or low levels can cause sluggish shifting, slippage, or even transmission failure. I recommend checking fluid color and level during every maintenance: light yellow and clean is ideal, while dark coloration or burnt odor means immediate replacement. Manual transmission fluid prioritizes lubrication, whereas automatic transmission fluid (ATF) offers comprehensive performance including cleaning to remove carbon deposits. Typically change every 50,000km to prolong lifespan and prevent roadside breakdowns. Always use manufacturer-recommended fluid that maintains stable performance across temperatures.
