Difference Between Gl 3 And Gl5 Gear Oil

The main difference between gl 4 and gl 5 gear oils is how much extreme pressure additive has been included in the mix.

Difference between gl 3 and gl5 gear oil. Millers classic green gear oil 90 gl1 and millers classic green gear oil 140 gl1. The viscosity has no relation with the api gear oil classification and should be chosen based on the recommendations from the manufacturer based on the temperatures where you will drive. Although api gl 3 oils are considered obsolete as they have less protection than api gl 4 oils some transmission manufacturers may still specify an api gl 3 gear oil. Some cars including later corvairs came with military specs instead of api gear oil specs.

They re usually used for manual transmissions which are operating under moderate to severe conditions. The main difference between gl 4 and gl 5 gear oils is the amount of ep additives. Gl3 is the next level of performance and has very limited applications. They have a light extreme pressure effect.

Sulphur phosphorus containing products are used as ep additive. The designation api gl 2 denotes lubricants intended for automotive worm gear axles operating under such conditions of load temperature and sliding velocities that lubricants satisfactory for api gl 1 service will not suffice. These oils are used for manual transmissions where the qualities of a gl 1 or gl 2 oil won t suffice but aren t quite requiring the amount of load that a gl 4 oil can handle. The difference between gl 4 and gl 5 gear oils 2 of 11 a traditional gl 4 gear oil of any given viscosity has about of the level of sulfur phosphorous additive that would be in the gl 5 product so the bond is not as strong and therefore can be peeled off.

When used in a differential there is a 30 increase in the torque load compared with a transmission so in this case the extra ep protection is required which is where an api gl 5 oil is best suited. There are 2 products available in millers green gear oil range of gl1 oils as follows. Mainly specified for french and italian fiat alfa cars which had very soft synchromesh.