Transmission Fluids: What Do They Do?

It’s a gorgeous day on the Monterey Bay! It’s amazing to look around and realize how blessed we are to live in such a beautiful place. With that said, let’s get back to our series on fluids. We have discussed the importance of engine oil, a clean fuel system and the purpose of antifreeze. This month, with the heat coming to our area and many of you traveling more, the topic of Automatic Transmission/Transaxle Fluid (ATF) comes to mind.

Your transmission is essential to facilitating the operation of your vehicle. Whether your car is equipped with an automatic transmission or a manual transmission, it is the transmission that provides the engine with the right amount of power for the wheels to be driven at the desired and given speed. Although a manual transmission works simply by a process of shifting gears, we will be focusing on automatic transmissions.

An automatic transmission automatically knows when to switch gears based on your driving conditions. Instead of you doing the work and knowing when to shift gears, it does it for you. Your automatic transmission basically provides a fundamental task for your engine to run correctly.

It is that reason that your automatic transmission fluid should be one of the fluids that are maintained regularly to keep your vehicle running efficiently. What does ATF do? Well, similar to what antifreeze does for your cooling system, automatic transmission fluid (ATF) lubricates your transmission for smooth operation. ATF also supports rotational speed and temperature range all while cleaning and protecting metal surfaces in your transmission from excessive wear and conditions the gaskets and seals.

Maintaining your transmission fluid is crucial to maintaining the transmission itself. Checking the fluid level is a task better left to your Certified Automotive Repair Specialist for a few reasons. There is the possibility of overfilling the fluid which can create a huge performance issue and eventually failure. Many of the vehicles on the road these days also have dipsticks that are very difficult to access and some have sealed transmissions that a special procedure needs to be performed in order to test the fluid level and condition. Let’s not consider the fact that we are all busy living life and I guarantee your transmission and checking its fluid level is not at the top of your to do list. This is a chore better performed when your vehicle is in for its normal oil and filter maintenance procedure.

Let’s get a little technical and talk about the chemistry of Automatic Transmission fluid. With technology and advancements in the automotive industry, fluids have changed along with them. Gone are the days of the standard ATF. We now have Dexron/Mercon, Highly Friction Modified (HFM), Synthetic, Type-F, and Hypoid Gear Oil and depending on what style transmission and the engineering will determine the type of fluid your car needs. Each of these fluids cater to the needs of each of the different styles of transmissions. Transmissions are very complex and depending on what fluid is recommended determines the composition of that fluid, although all of them consist of a high-quality oil.

Now that I have bored you with the different types of fluid, let’s talk about when you should expect to have your transmission serviced to ensure that your car continues to run smoothly. We always recommend review your vehicle maintenance guide first but know that most cars recommend a service around 60,000 miles. Regardless of what mileage you are at, it is good practice to have your fluid inspected periodically. This will give you an indication if something is starting to occur internally and could prevent a very expensive and un-necessary transmission repair or replacement, or even more so, an unexpected break down.

So, there it is! Transmission fluid maintenance in a nutshell. Remember, if you have any automotive questions about your car, be sure to contact your professional automotive service center for advice.