What is Transmission Fluid?

Transmission fluid helps to keep the moving parts inside your car’s transmission moving smoothly.

section of the automatic transmissionTransmission fluid helps to keep metal parts inside your gearbox from grinding down. This fluid will also help to keep the different parts of your transmission cool. Shifting mechanical gears is a hard task for your car. Transmission fluid allows your car to shift with ease while protecting the metal parts that rub against each other from wearing down.

Most people know about engine oil since it requires changing often – but most people don’t know about the importance of transmission fluid and when to change it.


Types of Transmission Fluid

Automatic vs Manual Transmission Fluid

Both automatic transmission cars and manual transmission cars require transmission fluid. There are two overarching types of transmission fluid available, automatic transmission fluid and manual transmission fluid. It is important to make sure you know whether your car requires automatic transmission fluid or manual transmission fluid in order to keep your car running properly.

Automatic Transmission Fluid

Automatic transmission fluid is used in all cars that have automatic transmissions, as well as some more modern manual transmission cars. Automatic transmission fluid is optimized for the requirements of an automatic transmission and helps with functions such as gear lubrication, brake band friction, and valve operation.

Manual Transmission Fluid

Also known as manual transmission oil is the fluid used in some manual transmission cars. Manual transmission fluid is never used in any automatic transmission cars and just because your car is a manual transmission does not mean that it uses manual transmission fluid. Manual transmission fluid can be a variety of different oils from normal motor oil to heavyweight hypoid gear oil. Always be sure to check the specifications for your car.


Synthetic vs Traditional Transmission Fluid

Traditional Transmission Fluid

Regular transmission fluid is transmission fluid that has been made by taking crude oil and reshaping the hydrocarbons to the specifications of different cars.


Synthetic transmission fluid is developed through a variety of chemical reactions, such as pressure and temperature to create the perfect transmission fluid for your car’s transmission. Synthetic transmission oil is less likely to oxidize, break down or thin out in higher temperatures.

But which do I choose, synthetic or traditional?

There is no clear-cut consensus on whether synthetic or traditional transmission fluid is better. Different car manufacturers will have different specifications.

When in doubt check the specifications for your vehicle or bring your car into the transmission specialists at AAMCO Colorado.


Look and Smell

While different companies will color their transmission fluid differently automatic transmission fluid is typically a thinner liquid that is colored red.

Automatic transmission fluid is this color so that it is easily distinguishable from motor oil and other fluids in your vehicle. Another reason is so that it is easy to spot a leak – typically you aren’t going to miss spotting a pool of green liquid in your driveway. It is also colored to help you avoid using the wrong type of transmission fluid by accident.

Manual transmission fluid will be much thicker and darker as it is typically motor oil or hypoid gear oil. Manual transmission fluid will also have a much stronger smell than it’s automatic counterpart.

Related: How Do I Know When My Transmission Fluid Needs to Be Changed?


How Often Should You Change Your Transmission Fluid?

While it not necessary to change your transmission fluid frequently, both automatic transmission fluid and manual transmission fluid will begin to break down or become contaminated over time.

It is important to regularly check the levels of your transmission fluid. If you begin to run low on transmission fluid, or your transmission fluid has begun to break down and become contaminated you will see a decrease in performance when shifting, and risk damaging internal gears as they grind together.

Hard Vehicle Use

Hard use of your vehicle, such as stop and go city driving or towing heavy leads may accelerate this time. This type of hard use increases temperatures in your car more frequently and can cause more strain on your transmission and transmission fluid. If you drive under these conditions regularly you may want to check your transmission fluid levels more often.

Symptoms of Low Transmission Fluid

Not sure how to tell if you are low on transmission fluid – you’re not alone, transmission fluid problems can creep up silently.

There are five main ways to identify a problem with your transmission fluid:

  1. Color: if your transmission fluid is red then it is good, if the fluid has started to brown this can indicate a problem.
  2. Puddles: If you have a transmission fluid leak you will most likely start to notice a small puddle forming under your car.
  3. Shifting: If you are noticing a delay or problem when shifting gears then it could indicate a problem with your transmission fluid.
  4. Warning Light: Most modern cars have sensors that can detect irregularities in your cars different systems. One of the most common dashboard light warnings that indicates a problem with your transmission fluid is the warning for high transmission temperature. This means that your transmission fluid temperature is hotter than normal.
  5. Smell: Most automatic transmission fluids have a sweet or tart odor, if you start to notice a slight burning smell it could indicate the need to check your transmission fluid.

The easy rule here is to look at the specifications for your car – how often does your manufacturer recommend the fluid be changed.

Related: Checking Your Transmission Fluid – An Infographic


Transmissions Made Easy with AAMCO Colorado

Still not sure when to change your transmission fluid?

Your local AAMCO Colorado location can do a simple test that takes a reading of your transmission fluids to let you know if there is a problem with your transmission fluid or it is time to change it. AAMCO’s expert technicians can also help you determine if your transmission fluid needs to be changed, or if your transmission needs further service.

Related: Benefits of a Transmission Fluid Flush

Time for your next transmission serivce? Have a transmission leak or need a repair? Contact us today to schedule an appointment with one of our transmission repair experts.

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