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Oil & Fluids

Type A Automatic Transmission Fluid – Ultimate Guide

Written by Nick Steiner

Your car depends on a lot of fluids to run smoothly, and I am not talking about just gasoline. Transmission fluids are probably the most important fluid used in your car, after the fuel itself.

There is a special type of transmission fluid that is specifically designed for your automatic transmission car.

Today we are discussing just that. We’ll talk about the automatic transmission fluids, their types, what they do, and when to change them.

What Is a Transmission Fluid?

Transmission fluid is a special, purpose-built fluid that is used to make your car’s transmission system more efficient and durable.

The components of your transmission system come into contact with each other frequently. They generate friction and heat, which can be seriously harmful to the components.

That is where transmission fluids come in. To put it simply, transmission fluids lubricate the bearings and metal parts inside your transmission system, absorb the heat, and minimize the friction so that your car can run without any issue.

What’s an Automatic Transmission Fluid (ATF)?

An Automatic Transmission Fluid AKA ATF is a fluid that not only lubricates your car’s moving parts inside the transmission but also provides hydraulic pressure and absorbs heat so that your transmission system works without any stress.

Your gearbox (transmission system) is prone to friction and decay every time you change your gears and ATFs protect your parts in such conditions. There are a lot of transmission fluids in the market depending on different transmission types.

As the name suggests, ATFs are made for automatic transmission systems (and some modern manual transmission systems too). There is a wide variety of ATFs for different purposes, but today we’ll talk about type A ATFs only.

Type A Automatic Transmission Fluid

Type A Automatic Transmission Fluid

Choosing the right ATF with specific viscosity, friction coefficients, and additives is crucial because using the wrong ATF can damage your transmission components, even the entire gearbox.

Introduced by General Motors in the mid-50s, Type A ATFs mainly were made from refined base oils and a few additives. Each transmission system requires a specific type of ATFs and using the wrong ATF can damage your car.

Modern ATFs consist of a wide variety of chemical compounds to make sure that the oil doesn’t boil/freeze, provide sufficient lubrication/pressure, prevent rust/corrosion, clean the parts, and perform many other essential functions.

Different Types of ATF

Dexron family

This is the 1st improved generation of ATFs that was made available by General Motors in the mid-60s. They are more stable, less reactive, and hydrotreated base oil compared to the basic AFTs.

Dexron II

They came into the market in the 70s and were the first GM transmission fluid for electronic transmissions. They featured better viscosity control and additional oxidation inhibitors than their predecessors.

Dexron III

They replaced Dexron II and were considered the most successful generation since they became the choice of transmission fluid for 80% of the contemporary time (before 2000). They featured improved oxidation and corrosion control.

Dexron IV

Dexron VI was introduced in 2006 and was primarily used in 6-speed rear-wheel-drive transmissions. They are low viscosity fully synthetic transmission fluid and are still in use today. Dexron VI replaced all other previous versions of ATFs.

Mercon family

The Mercon family ATFs came into the market to compete with GM Dexron 2 and started its journey with the Mercon-type CJ. They were originally developed for ford c-6 transmissions.

Mercon type H

They were designed to comply with Ford A specifications. Ford A specifications are different from General Motors, Dexron, and Ford type F transmission fluids.

Mercon V

Mercon V first came into the market in 1977 to support newer vehicles with a low viscosity fluid. They lubricated the internal parts faster and improved efficiency significantly. Additionally, Mercon V featured friction modifiers that increased performance by reducing friction.

Mercon SP

They enhanced the friction reduction capacity of their predecessors and were prevalent in 2005-2007s 6-speed automatics. Mercon SP can be used as a substitute for Mercon V. Some specific transmission systems like Ford Torqshift transmissions explicitly need Mercon SP.

Multi-vehicle ATF

Each transmission type is different and requires a different set of conditions to perform optimally.

Car manufacturers usually issue their set of unique requirements for a specific type of transmission system. Petroleum/oil companies follow the guideline while producing ATFs.

However, oil companies also produce a hybrid ATF that fulfills requirements for multiple transmission systems and can be used in a variety of different cars. They are called Multi-vehicle ATF and are becoming increasingly popular nowadays.

A word of caution though. Don’t go buy a random Multi-vehicle ATF and start pouring it into your car. Talk with a professional to know if your car is compatible or not. The worst mistake you can make is to put in the wrong ATF.

Remember, you have been warned!

What Does Automatic Transmission Fluid (ATF) Do?

Automatic Transmission Fluids (ATFS) use a combination of base oil and 20+ different additives

to reach the optimum performing condition. Transmission Fluids provide a wide range of services to make sure your vehicle is up and running smoothly.

The main purpose of the ATF is to transfer power throughout your gearbox. However, modern-day ATFs perform a number of other essential jobs such as:

  • Gear lubrication
  • Clutch friction operation
  • Valve body operation
  • Transmission cooling
  • Brake band friction
  • Torque converter operation

Using the wrong ATF can not only decrease your performance but also can put your whole transmission system at risk and we can’t stress this enough. Do not use any other ATFs other than what the manufacturer suggests.

There are a bunch of ATFs available for different transmission systems around the world and we strongly recommend you use only the ATF suggested in your car owner’s manual.

When to Change Your Automatic Transmission Fluid

When to Change Your Automatic Transmission Fluid

ATFs break down over time and become contaminated with particles and debris. Usually, car manufacturers recommend changing ATFs every 30,000-60,000 miles.

However, the mileage greatly depends on your driving style and your transmission type. Always follow the instructions your car manufacturer gave you for your specific vehicle.

Here are a few symptoms that indicate that you need a change of ATFs in your system:

Difficulties when shifting

If you encounter delays, bumps, and noises whenever you change gears, that is a pretty solid indication that your car needs a change of transmission fluids. The point of using AFTs is to minimize mechanical stress. If that can’t be done, you’ll definitely feel that while changing gears.

Roaring sounds

A transmission low on fluid might make a whining or buzzing sound. Additionally, such a car will make noise when you accelerate or go around corners.

Warning light

This is the most visible warning your car can give you. Modern cars have the technology to detect issues in your transmission system. Whether you notice the high transmission temperature light or the check engine light, check your transmission as soon as possible.

Transmission slipping

When your AFT is running low, you’ll feel slipping and sliding whenever you change the gear. This happens when there is not enough AFT to keep the fluid pick-up in the pan submerged.

Chattering

If you feel your car chattering on takeoff, this might be an indication that your car is running low on AFT. It’ll feel like you’re driving over a rumble strip and when that happens, check your AFT level.

Puddles

This usually indicates that there is a leakage in your transmission system. If you notice the formation of puddles under your car and the liquid isn’t water, check for leakage ASAP.

Color

If you check a discoloration in your AFT, it’s time to change. AFTs are usually light, clear-colored fluid that turns into a darker brown or muddy green color and that’s the indication you should change your AFT.

FAQs

1. What do ATFs look like?

Ans: Transmission fluids use petroleum dyes to make the fluid distinguishable from the other fluids used in your car and to easily spot any leakage. They usually come with a thinner consistency and a clear reddish hue. Modern ATFs can also be blue/green, purple, or amber.

About the author

Nick Steiner

Nick has been a car nut for his whole life as far as he can remember. His father was a car dealer who used to change and repair his cars himself. As a result, Nick had the opportunity to get around all sorts of cars and learned to get his hands dirty repairing vehicles from an early age.

Nick is a great fan of Japanese quality and German preciosity. His deep passion lies in older models that he believes have a flair that takes him back to his childhood. He also loves their durability and reliability when compared to the modern models.

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