Check Transmission Fluid Level – How To Check The Right Way?

Check Transmission Fluid Level – How To Check The Right Way?

August 6, 2021 1 By CarGuy

So, you have been thinking of checking your transmission fluid level and you want to know how to check transmission fluid level the right way? Don’t worry we got you covered and we will explain to you how to perform this practice the right way.

The transmission fluid is essential for your automatic transmission to work. Automatic transmissions are extremely complex and require an almost perfect amount of fluid to work. If they do not have the perfect amount of fluid. Most probably you are going to start experiencing some problems with your automatic transmission.

Some of these problems are slipping gears and transmission shudder issues. If you keep getting these issues then you have to take your car to a mechanics shop to inspect the condition of the transmission and see the condition of the fluid that is inside.

But the best is to check the transmission fluid level by yourself. Transmission fluid isn’t checked like any other fluid. In order to check the fluid, you need to follow some steps and we are going to answer all of these steps in this article. So, don’t worry.

In this article, first, we are going to learn more about how automatic transmission works and what type of fluid do you need. Then we are going to discuss about the service intervals and when you should service your transmission. Then we are going to answer the question of how to check transmission fluid level the right way. So, let’s begin.

What Is A Transmission?

The car transmission is also known as a gearbox. The gearbox’s role is to provide a controlled application of power. The transmission is converting the rotational power of the crankshaft into torque power and this power is transferred into the gearbox and then into the driveshaft and then to the back wheels.

Without a transmission, cars would not be able to handle all the power that is coming from the crankshaft and the power will be unusable. Because if you transfer the speed momentum of the engine directly to the driveshaft it’s going to snap in seconds. Because the engine turns much faster than you need it in order to drive your car on the road.

Imagine that you will have to stop on the road in traffic. If there weren’t transmissions you won’t be able to do this and you will probably have problems stopping and moving the car forward.

This is why some smart people have invented the transmission to convert all this power that the engine produces into torque and make the cars drivable and enjoyable. In order everyone to enjoy while driving their car.

How Does The Automatic Transmission Work?

The automatic is not like the manual where you select the gears manually and press the clutch. The automatic transmission is using hydraulic power to select gears and shift upwards and downwards through the gears.

This is why automatic transmissions are using torque converters to lock up in higher gear ratios to eliminate the power loss and offer some overdrive gears that automatically are actuating above some speeds. So, if your automatic transmission is slipping very often it means that you are running low on transmission fluid and you need to check transmission fluid level.

In automatic transmissions, everything depends on the transmission fluid. Every gear change is happening because of the input of the fluid. With its pressure, the shifter is changing the gears and is doing this work reliably. If there wasn’t a good fluid. Automatic transmissions wouldn’t be working this well as they are working now.

Most of the cars that are on the road in the US are automatics, and they still carry the popularity until this day. The automatics offer the best shifting experience and you will not going to be stressed out from pressing the clutch all day. Pressing the clutch in manuals can be frustrating work. Especially if you are stuck in bumper-to-bumper traffic.

Not to forget the clutch which suffers in these conditions. Also, the throwout bearing. These parts cost a fortune to replace. That’s why there are the automatics to save us from this trouble and enjoy the driving a bit more. But another problem with automatics is the transmission fluid. You always need to check the transmission fluid level if you want to keep the longevity of your automatic transmission. But what type of fluid does my automatic transmission need? Well, we are going to answer that question in the next chapter.

What Types Of Fluid My Automatic Transmission Needs?

ATF or hydraulic fluid is the standard fluid for automatic transmissions. This fluid was chosen to be the standard because of its characteristics and endurance.

If you want to run an automatic transmission you should rely on the best product out there and the ATF offers the best when it comes to hydraulic duties. Same with automatic transmission the fluid travels through tight cervices into your automatic transmission in order to get you the right shifts every time.

This fluid although serves a good purpose it’s relatively inexpensive and easy to get at every auto parts store. The same fluid is also used in the power steering system. So it has a double purpose in cars. Also, it is widely used in shock absorbers. When your shocks are starting leaking then they are leaking hydraulic fluid. I bet you didn’t know this fact.

Transmission Fluid Color

Red is the color of the transmission fluid. The red color was given to this fluid in order to be easily distinguishable from other automotive fluids, such as the engine oil or brake fluid.

This bright red color is easy to distinguish and when you go to the parts store you will going to recognize this fluid right away.

When the fluid is reaching its lifetime. The color is starting to turn to pinkish or brownish color. In some worn-out transmission fluids, the brown color is a dead giveaway that the transmission fluid was not changed for more than 60-80,000 miles.

Where Is The Transmission Fluid Located

The transmission fluid is located in many places. Unlike the regular oil that you are using that is located in the oil pan. The transmission fluid is located in the torque converter, in the transmission, and also in the transmission oil pan. That’s why when you are trying to check transmission fluid level there is a proper procedure. Something that we are going to explain a bit later.

What Are The Symptoms Of Low Transmission Fluid?

1. Transmission Slipping

One of the main symptoms of low transmission fluid is definitely transmission slipping. If your transmission slips gears then you are running on low transmission fluid and you are probably going to damage your car’s transmission if you continue driving this way.

In order to get these things resolved, you need to check the transmission fluid level. If the transmission is full with transmission fluid, then something else is going on inside of your transmission. There are a few probable causes why your transmission is slipping and that is a bad torque converter or a broken transmission.

2. Bad Torque Converter

The torque converter is known to wear down and cause slippage and you should be aware of this also. Since you checked the transmission fluid level and it is relatively good the torque converter can be the culprit.

These torque converters are playing a crucial part when it comes to shifting and they need to be in perfect working order so your transmission shifts precisely.

3. Transmission Shudder

Another symptom of low transmission fluid is transmission shudder. Yes, that’s right, your transmission is shuddering if there is low fluid in the transmission. This is because there is not enough fluid to make pressure and make the transmission change through the gears. This can also possibly damage your transmission if you haven’t changed the fluid for a long time. So, if you have shudder issues then the best thing is to get new transmission fluid.

4. Check Engine Light

Check engine light is also one of the symptoms of low transmission fluids. If you are having a low transmission fluid. It is very likely that you will have a reminder from your car computer about it. The downside of a check engine light is that you don’t know why this light turns on in the first place. So, in order to learn why it’s there, you need to connect your car to a car scanner.

If you are a DIY guy you probably have a code reader. Make sure that you connect this OBD2 scanner into the OBD2 port and let it scan. If you get some errors you will have to google them if your scanner is one of the simpler scanners. If you are running a more advanced scanner, you will be able to see what are the issues with your car directly from the scanner tool.

And after you checked your transmission fluid level you can refill the fluid and continue driving. But be aware since there is a lack of fluid the fluid is leaking from somewhere. Check the bottom of the car and the transmission pan. Make sure that there are no leaks around the gasket. If there are then you will need a new gasket, unfortunately. But this is a good chance for you to replace the fluid and also the fluid filter.

How To You Check Transmission Fluid Level?

So, we come to the important question. How to check transmission fluid level. In order to do this practice, you will have to get to the transmission fluid dipstick. This dipstick is usually yellow in color and is located next to the firewall. Way back at the end of the engine.

In order to check the fluid, you need to pull this dipstick out and see the level. If there is no dipstick then the only way to know how much transmission fluid you are having is to jack up the car in the air on a lift and pull a bolt that is on the one side of the transmission.

This bolt is used to refill the transmission fluid inside of the transmission. And in order to perform this check, you will need a pump and a hose. You need to pump new fluid inside of the transmission. And if the fluid is leaking from the side of the transmission that means that you are having enough fluid inside of your transmission. If there is low fluid you need to pump fluid until it starts to leak from the side. That will mean that the fluid is full and you don’t need more transmission fluid. But the most important is when to check transmission fluid level and in the next chapter, we are going to explain that.

Transmission Fluid Full When Cold Low When Hot?

Unlike other fluids on your car like the oil which is checked when the engine is cold and the oil is down in the oil pan. Automatic transmissions work a bit differently. So, in order to check the transmission fluid, your transmission fluid has to be at working temperature.

This is important for the dipstick method. If you are checking from the transmission directly then the transmission needs to be cold.

So, if you want to check the transmission fluid with the dipstick your car has to be up to temp as we said. You have to run it for a few minutes and let it go through the gears. This will allow the fluid to go through all of the crevices and start working.

Then when the transmission fluid is hot you can check the transmission fluid level. This way will give you the most reliable reading from all and you will know if you need to fill more fluid inside of the transmission.

You can also inspect the condition of the fluid and see if the fluid needs to be changed. And in the next chapter, we are going to learn when you should perform this practice. And in the last chapter, we are going to explain how you can change the transmission fluid DIY.

When Should Transmission Fluid Be Changed?

Transmission fluid should be changed every 30,000 to 50,000 miles. The more regular the transmission fluid changes the more life you get from your transmission.

If you are not changing your transmission fluid very often you are probably going to have some issues with the transmission sooner or later. Transmissions do not like bad transmission fluid. If you are running your car with bad transmission fluid. The transmission will start to shudder and slip through the gears. The more shuddering the more damage is done to your transmission.

This can be also permanent damage since the parts inside of the transmission are not lubed well enough and develop some friction. This friction may lead to metal shavings in transmission fluid. This will make your transmission fluid dirty and contaminated. This contamination will probably gonna damage the transmission in the long run. You will not get much out of it and will gonna cost you thousands of dollars to fix if it breaks. So, do your maintenance on time in order to avoid some of these problems.

How To Change Transmission Fluid DIY?

Since we have discussed how to check transmission fluid levels. Now it’s time to see how you can flush your transmission fluid in a DIY fashion. Because that’s why we DIY guys do. Just remember that you will need a lift in order to perform this job. Your car has to be in the air in order for you to have proper access to the transmission pan. You will also gonna need a new transmission fluid filter, new transmission fluid, and transmission pan gasket. So, without further ado, let’s dive into how this job is done.

Step 1

Step one involves lifting the car into the air and unbolting the bolts that are holding the transmission pan. Make sure that you have a big bowl that will collect this fluid and avoid being splashed with transmission fluid.

Step 2

Once removed the transmission pan then it’s time to scrape down the old gasket and make sure that everything is clean. Clean also the transmission pan from all of the metal shavings and other debris and then replace the filter.

Step 3

Now it’s time to reassemble. Make sure that you line up the gasket to the transmission pan correctly and then start tightening the bolts. Not too hard because you can ruin the gasket. First, tighten them loosely and then tighten them well.

Step 4

This is the last step and this involves refilling your transmission fluid. In order to do this, you have to remove a bolt that is on the side of the transmission. Remove the bolt and get a pump. You need to pump fluid into the transmission and make sure that when full starts to leak from the hole on the side of the transmission. Then just torque the bolt and you are good to go.

You can check the transmission fluid level for a good measure with the dipstick and you are done.


In this article, we have covered a lot when it comes to automatic transmissions. We explained how they work and how you can check transmission fluid levels.

Then we have covered the common symptoms of low transmission fluid and why you should always make sure that your transmission fluid level is good.

Then we have explained how to flush the transmission fluid in a DIY fashion. Remember that this job requires a lift and you will not be able to perform it if you don’t have it. So, the best thing is to visit your local mechanic and let him do all the hard work for you.