Transmission oil is gear oil , which circulates throughout your vehicle’s transmission . The transmission is the system that transmits energy from the engine to your wheels in order to move your car forward.
Made up of the gearbox , differentials , axles, universal joints , drive shaft and clutch , the transmission system is essential to the proper functioning of your vehicle. It has many mechanisms, bearings, gears and shafts that need to be lubricated in order to facilitate their movement , like the different parts of your engine are lubricated by engine oil.
There are different types of transmission oil, which must correspond to the different types of existing transmission systems. Thus, you will not use the same transmission oil for a manual gearbox as for an automatic gearbox .
It’s the transmission oil that helps you engage gears when shifting, allowing your engine to match the power demand. It also has the role of reducing heat emissions resulting from the friction of the various parts of the transmission and friction within the system.
Like engine oil , however, it is necessary to change your transmission oil regularly to ensure that it retains its cleaning and antioxidant qualities .
When to change the transmission oil?
Like engine oil , it is necessary to drain transmission oil in order to prevent impurities from forming within the transmission system. However, its periodicity is not the same as for engine oil.
It essentially depends on the type of gearbox fitted to your vehicle: generally, automatic gearboxes need to be changed more frequently than a manual gearbox.
The transmission oil change should be done every 95,000 to 160,000 kilometers for a manual transmission.
Changing the transmission oil should be done every 50,000 to 80,000 kilometers on average for an automatic transmission.
On recent cars, some manufacturers may now consider that some of their models do not need a transmission oil change: refer to the advice in your service book if necessary.
However, a few symptoms may tell you that your transmission oil needs changing, such as a burning smell or unusual noises when changing gears, or if your oil is too dark or grainy , a sign that particles are interfere with your transmission.
Which transmission oil to choose for your vehicle?
You must choose your transmission oil according to the type of transmission of your vehicle. There are two major types of transmission oil:
Transmission oil suitable for mechanical transmissions : it is suitable for manual and robotized gearboxes.
Be careful not to confuse transmission oil with engine oil . Just like the latter, you will find a viscosity index , but also different kinds of oil:
Synthetic oils : they are created in laboratories, reconstituted and enriched with additives, which further protect the transmission system from wear and increase its performance.
Transmission oil suitable for a manual gearbox will feature a high viscosity index , which corresponds to the thickness of the oil. You will have to look for indices like 75W90, 80W90 or 75W140. To decipher the viscosity index, here are our tips:
The first number corresponds to the viscosity of the oil when cold .
The transmission oil suitable for an automatic gearbox is a specific type of oil called ATF Dexron (for Automatic Fluid Transmission) , created by the American automobile giant General Motors.
It is distinguished by its red color, but also by its large quantity of effective additives against wear, foam, oxidation or transmission pressure. It is constantly reworked according to developments in automotive technology.
When choosing your transmission oil, do not hesitate to consult the recommendations of your manufacturer present in your maintenance book if you have the slightest doubt.
In order for your car’s transmission oil to run smoother, we recommend that you change the oil after using the vehicle for at least ten minutes. Park the car on a flat surface and raise it using a jack. Stabilize it on candles .
Access the drain plug located under the car and place a container or basin under it. Unscrew it with the key provided for this purpose. Let the transmission oil drain out. When the tank is empty, access the torque converter to drain it in turn.
Refill transmission oil
Choose the correct transmission oil for your vehicle and fill your gearbox housing using a plastic tube and funnel. Fill the crankcase to the maximum then replace the cap. Finally, remember to dispose of your used trnsmission oil in an appropriate treatment center, as it is a toxic product.
Where to put the transmission oil?
It is much more complicated to change the transmission oil yourself than your engine oil, and this operation again depends on your type of gearbox .
The location of the transmission oil tank depends on your vehicle model: it can sometimes be under your hood, but can also be more difficult to access because it is sealed at the gearbox, which can sometimes prevent emptying totally oil if you do not have sufficient technical knowledge.
Also, automatic gearboxes are relatively less accessible than manual ones. It is therefore best to leave the transmission oil change to a professional .
What is the price of transmission oil?
The price of a can of transmission oil depends on its type (natural or synthetic) and whether it is suitable for a manual or automatic transmission. On average, a liter of transmission oil will cost you between 5 and 10 € .
If you want to call on a mechanic to change your transmission oil, count on a budget of around 70 € .
Transmission oil now has no secrets for you! If it does not have to be changed as frequently as engine oil, it is nevertheless necessary (and preferable) to call in a professional when you approach the mileage recommended by your manufacturer, or at the slightest malfunction of your vehicle.