Skip to content


Free Shipping on Orders greater than $80.00
Free Shipping. $80.00 and greater.
Complete guide on automatic transmission fluid

Complete guide on automatic transmission fluid

One of the most important automatic transmission elements is the fluid, which lubricates parts such as gears, internal clutches and bearings in order for its functions to be carried out successfully. This fluid also has the transmission´s system cooling function preventing overheating.

When there are problems with the transmission fluid, such as leaks or levels that are too low, problems can arise that cause costly repairs. Therefore, choosing the fluid recommended by the manufacturer and keeping it at the appropriate levels is essential. Today we will give you a guide to solve all your questions about this fluid and help learn its most important characteristics.

Automatic Transmission Fluids: What are they?

The fluid or oil for automatic transmission, known as ATF for its acronym in English, guarantees the operation, performance and protection of the transmission systems. It is made up of esters, glycols, organophosphates, polyethylene and other components of synthetic origin that allow obtaining a liquid with a high viscosity degree, resistant to heat and friction.

This liquid prevents the metal parts from wearing out, helps the gears in the box not rub and be able to change smoothly. And it also creates the right pressure to set the entire machinery in motion.

To help distinguish ATF leaks, manufacturers often add color to the fluid, so ATF can be cherry red or green.

Brief history of automatic transmission fluids

In 1940, the world's first mass produced automatic transmission emerged: the 4 speed Hydra Matic developed by General Motors (GM), which required a special lubricant, known as Transmission Fluid No. 1 for the Hydra Matic Drive. This ATF was only available at Pontiac, Cadillac and Oldsmobile dealers.

Later, automatic transmission technologies required ATFs that were more resistant to extreme temperatures, as well as a more efficient distribution and marketing system that was available to all users of these vehicles.

Types of automatic transmission fluids

  • ATF TYPE A: It was used in the 1950s and has the appropriate characteristics for the models of that time, so its antioxidant and anti-wear power is low.
  • ATF TYPE F: It is designed for Ford and Jaguar brand models from the 1980s that have automatic transmission and power steering. It is characterized by high resistance to oxidation.
  • Dexron: It is the substitute for the GM brand ATF TYPE A. It emerged at the end of the 1960s for that time vehicles with automatic transmission.
  • Dexron VI: It is a GM ATF for automatic vehicles that works at low temperatures, has antioxidant additives and for thermal stability.
  • Mercon: It is a Ford fluid that entered the market in the late 1980s for the same brand models and its subsidiaries such as Lincoln or Mercury.
  • Mercon V: It is the evolution of the previous ATF for modern automatic transmissions, with greater resistance to vibration and temperature variations.
  • ATF+3, ATF+4 (MS 7176 and MS 9602): These are ATF used by the Jeep, Chrysler and Dodge brands that have a lower coefficient of friction, thus extending the life of the clutch.
  • SP-II, SP-III, SP-IV: They are ATF for automatic transmissions of Mitsubishi models.
  • Toyota WS (World Spec): It is a low viscosity ATF for Toyota models.
  • Oils for DSG double clutch transmissions: It is an ATF for automatic transmissions bathed in oil, which lubricate and cool the components.
  • Oils for Continuously Variable Transmissions (CVT): It is an ATF for vehicles whose automatic transmission must be treated with low-friction oils.

Important facts I should know about transmission fluids

The automatic transmission system should not have any ATF leaks or a lower level than recommended. If this happens it could get too hot, causing deposits and sludge to form, which prevent smooth gear changes as the clutches and bands will start to rub against each other.

Can it be maintained?

Yes. The automatic gearbox contains hydraulic, mechanical and electrical parts that can rub against each other, producing small residue that is absorbed by the ATF that circulates throughout the system. In this case, it could contaminate the parts and cause breakdowns, so the ATF should be changed every 60,000 kilometers or every 5 years.

How to know when the fluid is at a low level?

Under normal conditions, the automatic transmission is quiet and smooth for the driver. Therefore, when you start to hear noises, a rhythmic knock or a rattle during driving, there is probably a problem with the ATF low level.

The most obvious sign of an ATF leak is seeing green or red drops or smears of oil under the vehicle.

I don't know which one should I buy for my vehicle

There are many ATF formulations for automatic transmissions. Ideally, you should consult the manufacturer's manual for your vehicle, or ask a specialized mechanic so that you can choose the right oil.

When to change automatic transmission fluid?

If you notice red or green oil leaks under your car, if your vehicle is more than 5 years old or has more than 60,000 kilometers, or if during a check-up the mechanic detects that the ATF is contaminated, it is time to make the change.

How to change automatic transmission fluid?

Step 1. Warm up the car
Step 2. Raise your car
Step 3. Remove the drain plug to completely drain the ATF
Step 4. Remove the transmission tray
Step 5. Scrape off the old gasket
Step 6. Replace the filter and o-ring
Step 7. Install the new gasket on the transmission pan
Step 8. Reinstall the transmission pan
Step 9. Lower the vehicle
Step 10. Fill the transmission fluid
Step 11. Check for leaks

We hope this information is useful to you. At the Sun Transmissions automatic transmission online store you will find a wide variety of automatic transmission parts, also we have many automatic transmission fluids, automatic transmission sensortransmission pan gasketautomatic transmission filters, and much more. So with us you find the one that your vehicle needs.

For more information, contact us through the online chat where we will gladly assist you and answer all your questions.

Previous article Power steering torque sensor, what is it and how does it work
Next article Know the power steering parts and what is their function

Compare products

{"one"=>"Select 2 or 3 items to compare", "other"=>"{{ count }} of 3 items selected"}

Select first item to compare

Select second item to compare

Select third item to compare