Signs You Have Too Much Transmission Fluid

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So you think you might have put too much transmission fluid in your vehicle. What do you do now?

This happens more than you think, so don’t stress any longer.

In this post, I’ll tell you what symptoms you should look for to determine if you put too much transmission fluid and what you can do to solve it.

Let’s get started.

1. Dipstick Reading “Full”

One of the easiest ways to determine if you put too much transmission fluid in your car is by reading the dipstick.

The dipstick is a device built into the engine that makes it easy to measure if you have too much transmission fluid.

If you see that your transmission dipstick is near or over the full line, this is a good sign that you should inspect further.

Although dipsticks are easy to use, they are not always accurate even if you follow the proper technique.

To get an accurate measurement, start by cleaning your dipstick. Measure it several times to get an accurate number.

Pull out the dipstick and wipe it clean. Once clean, you place it back into the transmission dipstick port slowly.

This will prevent from disrupting the oil can, causing an inaccurate measure.

Finally, pull out your dipstick.

Pro tip:

To minimize inaccurate measurements, run your vehicle for 5-10 minutes before checking your oil. This will thin out the transmission fluid, giving you the most accurate measurement.

It will prevent any transmission fluid to get stuck on the transmission dipstick port’s inner walls.

2. Hard To Shift Gears

A transmission with too much or too little fluid can be a reason why you might have a hard time changing gears.

Excess transmission causes an increase in the pressure inside your transmission. Excessive pressure build-up tends to create a foam that hinders lubrication. As a result, fluid leaks and shifting gears become a difficult task.

The increased pressure build-up will also come with another significant problem, which is air contamination. Not only that, you might even experience gear slipping and hard shifts as well.

3. Transmission Fluid Leakage

Other than using your dipstick, the easiest way to determine if you have too much transmission fluid is a leak. 

There are two reasons that transmission fluid could be leaking from your car. 

  1. Wear and Tear 
  2. Overfilled transmission fluid 

If you do overfill your transmission, the liquid will gather under your transmission. This is typically in the center or towards the front of the engine. 

Transmission fluid is slightly red, slippery, and oily, which makes it easy to identify. If you do find transmission fluid 

It can be relatively easy to determine whether you overfilled or your leak is from wear and tear. 

First, when you overfill your transmission fluid, you will see it on the transmission dipstick port or around the top of your transmission. 

If you have a leak due to wear and tear, you won’t find transmission fluid near the port or the top of the transmission. 

There are a few places where transmission fluid will leak due to wear and tear. 

If you don’t see transmission fluid at the top, you can check in the following locations 

  • Pan gasket
  • Cooler lines
  • Torque converter seal.

4. Grinding or Humming Transmission Noises

Transmission systems tend to make some noise while in use since their parts are always moving. One sign of excess transmission fluid is unusual noises.

This includes grinding or humming noises.

Think of these kinds of noises as warning signs that the system is giving you. Whining noises can mean that there is little or too much fluid. Grinding noises may come from the gears that have a hard time moving due to the lack of lubrication.

5. Engine overheating

There are too many factors that can cause the engine to overheat. However, most of these are due to insufficient lubrication.

We all know that oil is the one responsible for keeping the engine running. With that, what’s the transmission fluid got to do with this issue?

Well, too much of this fluid will affect the performance of the transmission. As a result, the engine gets strained from trying to get the vehicle moving.

6. Slipping Transmission

Slipping transmissions occur when the gears in the transmission do not engage correctly and fall out of sync.

When you are driving, your vehicles are unresponsive or slow to respond when you push on the gas pedal.

A slipping transmission can also cause unwanted noises by the transmission such as clicking or grinding.

If you experience a slipping transmission, this is a symptom that there is too much oil in your transmission.

Consequences of Overfilling your Transmission

The consequences of adding too much oil into your transmission can vary from minor cleaning to full-on failure of your transmission fluid. 

The reality is that the consequence depends on how fast you address the issue and what you do to solve it. 

The best solution is to immediately take action to reduce the amount of transmission fluid in your vehicle. 

Below are some of the consequences you could face if you have too much transmission fluid in your car. 

1. Overheated Transmission

We’ve already gone through why an engine overheats, right? Now, let’s talk about the transmission and what causes it to overheat.

Overheating is usually caused by pressure and friction that comes from overfilling.

Since transmissions are hot, once you pour the fluid, it tends to expand. This is why you should leave a little space for allowance to avoid leakage.

Not only would it leak, but the frame can also get broken. The metal plates would then create high levels of friction that would damage the gearbox.

Here are the two common signs of an overheating transmission:


Acrid burning odor

Transmission fluids play a crucial role in the system. It allows forces to pass through the various parts of the transmission.

Not only that, but it also helps keep everything lubricated while absorbing heat.

Over time, it’s bound to lose its effectiveness. From a red-colored liquid, it slowly becomes dark. The fluid will then start to burn and turn black. During this process, it emits harsh and unpleasant fumes. You’ll even smell this from the inside of the vehicle.


Slow response times

Do you experience a slight delay when you shift the gear? Well, this might be the transmission’s way of telling you that it has a low level of fluid.

Lagging occurs since the system has a hard time imposing the desired gear change. This could lead to overheating, so it’s better to always check the fluid levels.

2. Depleted Oil Quality

If the transmission fluid foams up, it may tend to stick to the top of the transmission. It can also stick to the gears, which may cause a possible jam.

We all know how essential transmission fluids are. Once foams appear, the fluid can no longer produce the needed pressure to create friction. As a result, the system will experience oil starvation.

3. Reduced Fuel Lubrication

I’ve mentioned that the foaming of the transmission liquid reduces lubrication.

Now, how does the liquid foam up? This may be due to the presence of detergent and anti-oxidation additives.

Excessive flow, high pressures, narrow canals, and penetration of air. All these are also possible causes.

Over time, dirt, grease, and water can enter the system and affect the fluid.

4. Complete Transmission System Faliure

From overheating to leakage, all these will be too much for the transmission to handle in the long run. This is why it’s never okay to ignore the signs, even if they aren’t that severe. 

How To Solve Overfilled Transmission Fluid?

1. Siphon the Transmission Fluid

One of the easiest ways to remove excess fluid from your transmission is using a siphon.

Don’t worry; I am not expecting you to use a whose and suck until you start the oil flow.

Today there are easy tools that you can use to help you remove excess fluid.

In most cases, the siphon contains a pump or syringe that allows you to siphon out any liquids.

All you need to do is insert one end of the whose into your transmission port. Using the pump or syringe, start pumping until you remove enough oil.

2. Draining Transmission Fluid

The other way to solve excess transmission fluid is to drain your transmission. Depending on your vehicle, you may have an overflow valve under your car that allows you to remove any excess fluid easily.

Most automatic transmission vehicles do not have this, but it is available in some manual transmission vehicles.

All vehicles do have a drain valve. Using this valve, you can remove any excess fluid in your transmission.

When you do this, make sure you have a large bucket ready to catch any oil. Draining your transmission oil is not always easy and can be messy.

Some experts advise full drainage and refill if you do add too much transmission fluid. This is not required, but it can make draining and measuring the proper amount of transmission fluid easier.

3. Seek Professional Help

One of the easiest ways to remove excess fluid from your transmission is using a siphon.

Don’t worry; I am not expecting you to use a whose and suck until you start the oil flow.

Today there are easy tools that you can use to help you remove excess fluid.

In most cases, the siphon contains a pump or syringe that allows you to siphon out any liquids.

All you need to do is insert one end of the whose into your transmission port. Using the pump or syringe, start pumping until you remove enough oil.

Frequently Asked Questions

Will a Slightly Overfilled Transmission Get Damaged?

A slightly overfilled transmission will not get damaged if the quantities are minor. To avoid serious issues, you can only overfill your tank with less than 0.5 liters of fluid without causing damage.

Your transmission is designed to handle some excess transmission fluid. The standard transmission can hold 9 to 13 quarts of transmission fluid.

Thirteen quarts is the standard if you drain the transmission fluid in your car. In most cases, transmission tanks can handle approximately 13.5 to 14 quarts. This gives you some room to make an error.

If you wait to add transmission fluid until your check oil light turns on and do not drain your old oil, then you probably want to add around 9 quarts of fluid.

Most cars will signal the check oil light when your transmission reachers between 3-5 quarts.

How To Read Your Transmission Fluid Color?

Most new and clean transmission fluids are bright red. However, once the color starts to change, should this concern you?

It might turn light or dark shade of brown, so you should know what this all means.

These colors can give you a clue as to what the condition of the transmission is. They can also provide warnings to alert you of any issues that need immediate attention.

This is why we’ll go through the meanings of these changes in the colors of transmission fluids.



Condition: Excellent

As I said, a transmission fluid that is bright red means that it’s new and clean. Always check the fluid to make sure it stays that way. You can also have it flushed often to reduce the chances of having issues in the long run.


Light brown

Condition: Good

A transmission fluid that’s light brown is still somewhat acceptable. However, this would need more maintenance. Make sure to flush or change it more frequently.


Dark brown

Condition: Serious

Once you see that the transmission fluid is already dark brown, it’s old and contaminated. The fluid is no longer able to provide the proper lubrication.

It’s also a sign that the internal temperature is higher than usual, leading to overheating. You should immediately have the fluid changed to prevent transmission failure.



Condition: Poor

A black transmission fluid means that the fluid is very dirty, old, and has oxidized. This is where you’ll start to notice the various signs and symptoms mentioned earlier. You may want to seek professional help for this.



Condition: Serious

A foamy transmission liquid is a result of its mixing with coolant or water. This will usually occur if there’s a leak in the radiator.

Coolant in the transmission is never good. This prevents the moving parts from receiving the proper lubrication.

You would need to go to a professional to have the leak fixed. The transmission filter and fluid would also need flushing and changing.

How much transmission fluid should I add?

Usually, you would only need to pour about ½ qt of fluid at a time. It would take about 9-13 qt to fill.

Although, this would depend on whether you’re adding or replacing the fluid.

Starting the engine and letting it run is always ideal for you to get the correct reading. Keep on adding the fluid until it reaches the ‘full’ level on the dipstick.

Always watch out for the cold mark on the stick if the engine is cool. The transmission fluid should be at its upper end. The hot one should be at the upper end of the hot mark.

The fluid level should always be within the safe zone.

2 thoughts on “Signs You Have Too Much Transmission Fluid”

  1. It could be a number of things since it goes into reverse, but you should start with the obvious, which is draining the excess fluid, and check if it resolves the problem.


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