In almost all cars, the automatic transmission oil level is checked with the engine running and in the position of the range lever in the “P” position. With the help of a dipstick, the oil level in the box is determined; there are several notches on it. The top two, sometimes one, which corresponds to the normal oil level in the automatic transmission, warmed up to a temperature of 90 degrees, it is usually marked with the inscription "Hot".
We change the oil in the following sequence: first you need to warm up the gearbox after driving 10-20 kilometers, after warming up, drive the car to the place of oil change, stop it on a flat area, pull out the dipstick in order to check the oil in the automatic box, wipe it, and again lower it into the soup pipe until it stops, and pull it out again. It happens that there are lower marks on the dipstick that allow you to check the oil level when the box is cold, but they are intended only for an approximate check, the final level should still be checked when the oil is warmed up.
Often on the dipstick is indicated the position of the hose, at which it is necessary to check the oil level, and the type of oil used in this box. There are Acura and Honda cars with such a nuance: they should check the oil with a warm box, but with the engine turned off.
A very low oil level in the automatic gearbox is dangerous in that the pump captures air with oil, as a result an air-oil mixture will be obtained, which is compressed and has low heat capacity and thermal conductivity. The oil loses its most important property and becomes compressible. The consequences of these structural changes will be: a drop in pressure in the system, overheating of the automatic transmission, poor lubrication of rubbing parts. Driving a car with such oil in the automatic transmission will very quickly lead to its failure. The oil can foam due to the rotation of the automatic transmission parts, if the level is exceeded, while the rotating parts of the automatic transmission begin to dip into the oil, foaming it. Its foaming does not occur immediately after the engine is turned on, as in the case of a low level, but in the driving cycle, especially at high engine speeds.
In both the first and second cases of an incorrect oil level, the foamed oil increases in volume and is thrown out through the breather in the automatic box. Look under your car, if so, you will often see that the box is covered in oil.
