Understanding your vehicle’s transmission fluid

Understanding Your Vehicle’s Transmission Fluid

Owning a car is often a matter of pride and luxury- one of the most valuable possessions that allows you to travel at your own convenience. Having spent all that money on a vehicle, it is imperative that you keep it in top shape and in good condition. There are numerous fluids in the vehicle such as the radiator oil or the air cooling refrigerant. While you may know about the specific questions related to engine oil, one of the other essential fluids is the transmission fluid.

What is a transmission fluid?

To understand what a vehicle’s transmission fluid does, it is important to understand what transmission in a car means. This refers to the gearbox that uses gear and gear trains to provide speed and torque conversions from the engine to the wheels. Therefore, a transmission fluid is used to lubricate the components of a car’s transmission so that it can perform optimally. This also cools the inner workings of the transmission and provides the fluid force required for a transmission to shift.

The purpose is to keep the transmission lubricated and clean, cool, sealed and chiefly, to transfer power.

How does the transmission fluid work?

The act of shifting gears, engaging and disengaging the transmission and rotating the transmission bands and linkages produce heat, which produces a constant need for lubrication. The circulating transmission fluid flows through a series of small channels and ports within a transmission. These are small openings that let it lubricate and cool the critical parts of the transmission.


MTF stands for manual transmission fluid and ATF stands for automatic transmission fluid. The differences in each of these lies in the way that these fluids function. With automatic transmission vehicles having taken precedence over manual transmission, it is still necessary to know how these fluids work. An automatic transmission is more complex than a manual.

An ATF is a hydraulic fluid as automatic transmissions use pressurized fluid to change gears. When a fluid is too thick or when the viscosity is too high, this can fail to flow fast enough for efficient gear shifts. Therefore, ATF has a lower viscosity than MTF. Automatic transmission fluid must also contain foam inhibitors as fluid that collects foam can fail as a hydraulic fluid. MTF has a higher viscosity that helps the fluid develop a thick, durable protective film.

ATF is made to give accurate frictional properties that are not needed of MTF as automatic transmission requires that engagement and disengagement must occur seamlessly in clutch packs made of metal plates that are coated in friction material. Automatic transmissions are made up of a variety of sun, planet and ring gears that need lubrication to safeguard against wear. Therefore, the transmission fluid must create a durable film on metal surfaces to avert metal to metal contact.

Lastly, heat can cause oxidation and break down the automatic transmission’s fluid. Therefore, a good ATF should have protection against heat. A good MTF or gear oil  will protect synchros to ensure they last as designed and promote smooth shifts.

Which is the right transmission fluid for your vehicle?

Ideally, you should start by looking at the owner’s manual, when choosing the correct transmission fluid. Firstly, you should pick the right type for the vehicle- Dextron or Mercon.

Secondly, you need to choose between synthetic or conventional fluid. Synthetic transmission fluid tends to be costly but offers better performance and is durable even at higher temperatures. But some car models such as some older ones will benefit by using conventional fluid, especially if they haven’t been introduced to synthetic. Switching between the two can cause unwanted transmission repair issues.

Now that you have chosen the correct type and quality, you should be looking at the right brands. Divyol has specialty lubricants that ensure your vehicle has the desired properties needed in a transmission fluid.

When do you need to change the transmission fluid?

A transmission fluid is a lubricating and cleaning fluid that supports gear shifts, cools down the transmission and lubricates the moving components in the transmission. However, if the transmission fluid is not a good condition, this could lead to damage.

Transmission fluid deteriorates over time and should be changed frequently enough to prevent damage. How often this should be changed will depend upon the usage of the transmission. If the vehicle is primarily driven in the city, temperature of the transmission increases as the car is frequently on and off. This results in increased pressure on the transmission fluid. Carrying a heavy load in the car with a high torque will also increase this pressure.

A change in transmission fluid is advised every 90,000 kilometres. However, do remember that this differs according to the car. Refer to the manual to see the advised range before the transmission fluid deteriorates.

How to know if the transmission fluid is low?

When the transmission overheats, this is caused by low fluid or depleted fluid as a result of irregular fluid maintenance. Check for signs of leakage of the fluid on the ground where the car has been parked or if the vehicle has a dipstick, check the transmission fluid levels everytime the oil is changed. Even if this is slightly low, this means that a smaller leak will turn into a larger leak if the problem is not addressed early.

Car maintenance is no easy task but we hope that this blog helped answer some queries and provide some useful information about transmission fluids. In order to extend the lifespan of a transmission and the vehicle in general, be sure to keep a regular check on the fluid levels.

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