Gearbox oil gravity change or cycle machine change

When we usually maintain the vehicle, it seems that the focus of attention is on changing the engine oil. But little is known about changing gearbox oil. At present, there are two ways to change gearbox oil (specifically, automatic gearbox oil), one is gravity oil change, and the other is circulating engine oil change.ThatShould the gearbox oil be changed by gravity or by cyclic engine?Let's follow the editor to understand the mystery of these two oil change methods.

Gravity oil change method:

I believe that the students are very familiar with the principle of gravity oil change, because the engine oil is changed by gravity. But unlike the engine, the internal parts and structure of the gearbox are more sophisticated and complex. If the transmission oil is drained only by gravity, it will definitely not drain cleanly, especially the oil in the hydraulic torque converter and various valve body oil passages, which is very difficult to drain. When we use the gravity oil change method to change the gearbox oil, we can only change more than 60% of the oil at most. In addition, more than 30% of the old oil will remain in the gearbox. Therefore, the disadvantage of the gravity oil change method is that the oil change is not thorough enough; however, its operation is simple, and the amount of oil used is small, and the oil change cost is relatively low.

Circulating machine oil change method:

As the name suggests, the oil change method of the circulation machine requires the use of a circulation machine for replacement, and the operation steps of this method are more complicated. First, a large amount of gearbox oil is discharged by gravity, and then the oil remaining in the gearbox is replaced by a new and old oil cycle method with a circulating machine. In this way, the oil change is more thorough and can basically replace 90% of the oil in the gearbox. But the oil consumption is also larger, and the oil change cost is higher.

Summarize:

Although theoretically speaking, the circulation engine oil change method is more advantageous than the gravity oil change method, but because many 4S shops do not have a circulation engine at all, the main force for replacing transmission oil in our country is the gravity oil change method. .