Classification, selection and precautions of gear oil for automobile manual transmission

1. Classification of manual transmission gear oil:

At present, there are two types of gear oil in the domestic market: one is foreign gear oil, which is classified by SAE (Society of Automotive Engineers) and API (American Petroleum Institute). The other is classified according to the domestic gear oil classification method.

1. Classification of foreign automotive gear oils

The classification of SAE automotive gear oil is divided into seven viscosity grades: 70W, 75W, 80W, 85W, 90, 140, and 250. "W" is used to indicate winter size gear oil, and "W" is not used to indicate summer size gear oil.

Now there is a multi-grade gear oil, such as: 80 w / 90, 85 w / 90, 80 w / 90 means that this gear oil can be used at an ambient temperature of the lowest - 30 ℃ and the highest - 10 ℃.

According to the classification of API and the severity of working conditions, gear oil can be divided into 6 grades of use: gl-1, gl-2, gl-3, gl-4, gl-5, gl-6.

In recent years, with the development of automotive technology, many car manufacturers have higher and higher requirements for automotive gear oil, so SAE and ASIM (American Society for Testing Materials) have introduced a new level, say mt-1 pg-2, mt -1 is mechanical transmission oil, its quality is higher than gl-4 standard. The quality requirements of pg-2 are higher than gl-5.

2. Classification of domestic automotive gear oils

There are also two classification methods for domestic gear oil:

First, according to the viscosity classification, the classification standard is also classified according to the SAE standard.

Another category is:

Ordinary automotive gear oil, equivalent to API grade gl-3,

Medium duty vehicle gear oil, equivalent to API grade gl-4,

Heavy-duty vehicle gear oil equivalent to API grade gl-5.

II. Manual Transmission Gear Oil Selection

When selecting gear oil for automobile transmission and differential, it is best to select the type of gear oil viscosity and quality grade in accordance with the provisions of the automobile operation manual. You can also refer to the following methods:

1. Select the viscosity grade of the gearbox according to the local seasonal temperature.

The minimum ambient temperature corresponding to the gear oil viscosity grade is: 70w(55℃), 75w(to 40℃), 80w(30℃), 85w(~ 20℃), 90(10℃), 140(10℃ °C), 250 (20 °C)

In recent years, a large number of imported gear oils have been produced and sold domestically and sold in the domestic market, trying to use international standard labels, gear oil level SAE viscosity grade labels and API quality rating labels, and there are also some domestic labels for gear oils, domestic and The corresponding labels of international standard gear oils are as follows:

No. 20 ordinary gear oil (domestic trademark), suitable for winter GM gear transmission, corresponding to international trademark SAE grade 90, API grade gl-2.

No. 30 ordinary gear oil (domestic trademark), suitable for summer automobile gear transmission in the north and south of the Yangtze River, corresponding to the international trademark SAE grade 140, API grade gl-2.

No. 22 residual oil type hyperbolic gear oil (domestic trademark), suitable for hyperid gear transmission in winter, corresponding to international trademark SAE grade 90, API grade gl-3.

No. 28 residual oil type hyperbolic gear oil (national standard), suitable for summer high-speed gear transmission vehicles, in line with international standard SAE 140 grade, API gl-3 grade.

18-point hyperbolic gear oil (Chinese label), suitable for ambient temperature - 10 ~ 30 ℃, hypoid gear transmission, corresponding to international label grade SAE 90, API grade GL - 4.

26-point hyperbolic gear oil (Chinese label), suitable for hypoid gear transmission vehicles in areas with an ambient temperature above 32°C. Corresponds to international label SAE grade 140, API grade gl-4.

No. 13 fractionated hyperbolic gear oil (Chinese label), suitable for hypoid gear transmission vehicles with ambient temperature at 35 ~ 10 ℃ - low temperature area, the corresponding international label grade is SAE 85w, API grade is GL - 5