Classification of Transmission Fluid and Gearboxes

https://www.sdrboil.com/transmission-oil

Classification of Transmission Fluid and Gearboxes

Transmission fluid is an oil product to keep the gearing system clean, which can play a role in ensuring the normal operation of the transmission and prolonging the life of the transmission device, and it has the ability to resist low temperature, and can also carry out extremely effective lubrication effect at low temperature, and reduce the loss of oil products under severe operating conditions. According to the different structure of transmission, transmission fluid is divided into automatic transmission fluid and manual transmission fluid.

Automatic Transmission Fluid

ATF (Automatic Transmission Fluid) for short, is a special fluid for automatic transmissions. Early automatic transmissions did not have specialized fluids, but used engine oil instead. The engine oil as automatic transmission fluid was quickly eliminated because the working conditions and technical requirements varied greatly. The special automatic transmission fluid used today is both the transmission fluid for the torque converter, the lubricant for the planetary gear structure and the hydraulic fluid for the shifting device. Automatic transmission fluids are generally changed every 120,000 kilometers for normal driving conditions and every 60,000 kilometers for severe driving conditions.

Manual Transmission Fluid

Generally known as gear oil, according to its quality level, the American Petroleum Institute of automotive gear oils are divided into five grades (GL-1 ~ GL-5). GL-1 ~ GL-3 performance requirements are lower for general loads under the spur, bevel gears, as well as gears such as gearboxes and steering gears, lubrication. GL-4 is used for high-speed low-torque and low-speed high-torque conditions, the automobile hyperbolic gear driveshafts and lubrication of the manual gearbox. GL-5 has the highest level of performance and is used for lubrication of hyperbolic gear shafts and manual transmissions under harsh operating conditions and high shock loads. Transmission gear oils are generally changed once every 2 years or 60,000 kilometers under normal driving conditions.

And according to the function classification, the transmission can be divided into: manual transmission (MT), mechanical automatic transmission (AMT), dual clutch transmission (DCT), automatic transmission (AT) and continuously variable transmission (CVT).

Manual Transmission (MT)

Consisting of gears for each gear and a mechanical clutch, it has a simple structure, high transmission efficiency and is very reliable. However, it is a bit cumbersome as it requires purely manual operation and you have to press the clutch. However, it is also fun to drive and allows you to improve your driving skills.

Mechanical Automatic Transmission (AMT)

Similar to the structure of a manual transmission, except that the whole shifting process can be done by an electronically controlled element and does not need to be manually controlled by yourself. However, due to the lack of automation of the electronic control system, there is a noticeable stutter when shifting gears. It is often used as a low-cost automatic solution for economy cars; in addition, its simple structure and high shift efficiency make it commonly used in racing cars.

Dual Clutch Transmission (DCT)

Similar to a manual transmission structure, it consists of two sets of clutches. When traveling in the first gear, the gears of the second gear will be automatically combined and ready to start working, shifting gears quite fast, but the smoothness is a bit poor at low speeds. Initially used in sporty cars, it is now widely used in all types of vehicles.

Automatic Transmission (AT)

Composed of components such as a torque converter, the structure is relatively complex. Some of the power is consumed in the gearbox during the shifting process, and the transmission efficiency is slightly lower. However, it shifts smoothly and has mature and reliable technology, making it the choice for most automatic models.

Continuously Variable Transmission (CVT)

Composed mainly of two vertebrae shafts and a steel chain, it can control the transmission ratio at any time, and is theoretically the smoothest and most economical of all gearboxes. However, due to its structure, it is unable to withstand a lot of torque during intense acceleration. If you are looking for an economical and comfortable car, this gearbox is usually used.