What is transmission fluid and what is it for?
Transmission fluid is used to lubricate the vehicle's transmission components for optimum performance. In vehicles with automatic transmission, this fluid also acts as a coolant. There are several types of automatic transmissions...
Transmission fluid is used to lubricate the vehicle's transmission components for optimum performance. In vehicles with automatic transmission, this fluid also acts as a coolant. There are several types of automatic transmission fluids, and the type used in individual cars and trucks depends on the type of transmission inside. As the name suggests, automatic transmissions use regular automatic transmission fluid. However, manual transmission fluid can be varied using either regular engine oil, gear oil known as heavy hypoid gear oil, or automatic transmission fluid. The type of transmission fluid for use in standard transmission vehicles can usually be found in the maintenance section of the owner's manual.
Although the main function of automatic transmission fluid is to lubricate various parts of the transmission, it can perform other functions as well:
- Clean and protect metal surfaces from wear
- Gasket condition
- Improve cooling function and reduce high operating temperatures
- Increasing rotation speed and temperature range
Different types of transmission fluid
There are also many different types of transmission fluids that go beyond the simple division between automatic and manual transmissions. For best high temperature performance and full fluid life, use the gear oil or fluid recommended by your vehicle manufacturer, usually listed in your owner's manual:
Dexron/Mercon: These varieties, available in various grades, are the most commonly used automatic transmission fluids today and contain friction modifiers to better protect the internal surfaces of the transmission.
HFM fluids: High friction fluids (HFM) are very similar to Dexron and Mercon fluids, but the friction modifiers they contain are even more effective.
Synthetic fluids: These types of fluids are often more expensive than Dexron or Mercon, but are better able to withstand extreme temperature changes and greatly reduce friction, oxidation, and shear.
Type-F: This type of automatic transmission fluid is used almost exclusively in vintage cars from the 70s and does not contain friction modifiers.
Hypoid gear oil: This type of gear oil, used in some manual transmissions, is highly resistant to extreme pressures and temperatures.
Motor oil: While motor oil is commonly used in a car engine, it is suitable in a pinch for lubricating manual transmissions because it has a composition and properties similar to gear oil.
Depending on your vehicle type and length of ownership, you may never have to worry about the type of transmission fluid you use. This is because there is no need to change it frequently. In fact, some automatic transmissions never require a fluid change, although most mechanics recommend changing the fluid every 60,000-100,000 to 30,000-60,000 miles. Manual transmissions require more frequent transmission oil changes, typically every XNUMX to XNUMX miles. If you are in doubt whether your vehicle needs fresh transmission fluid or oil and what type to use, feel free to consult one of our experienced mechanics.
