Sometimes an inexperienced mechanic or DIY driver tends to add too much transmission fluid. They think that adding a bit more than less is good, but that cannot be further from the truth. It can have dire consequences and you should learn the symptoms of too much transmission fluid in your vehicle.
The most common symptoms of excess fluid levels in the transmission are strange noises coming from the transmission. Also, transmission fluid leaks and poor lubrication of the parts are frequent culprits. That leads to faster wear of all components.
If you want to learn what problems the excess transmission fluid can make and how to recognize all of them, stay with us. We will cover this topic from top to bottom, so you will not have to worry about this problem whatsoever.
What Is A Transmission Fluid For?
The automatic transmission, when compared to the manual transmission, is much more complex. It demands frequent maintenance. Manual transmission vehicles don’t have such a full schedule regarding their maintenance. Automatic transmissions do because they are technologically more advanced.
The main functions of the ATF are transmission cooling of the moving parts and the lubrication of the transmission gears. They also cool and lubricate other components. The ATF provides the connection between the engine’s output power and the transmission. That is done through a fluid coupling called a torque converter. That way it allows the gears to easily shift.
Another important feature of the ATF is keeping the transmission cool. These moving parts get very hot during work, and the ATF is there to keep them in at optimal temperatures. That way, the excessive wear of the components is prolonged. All these elements are under heavy strain in everyday work. That is why it needs proper lubrication and cooling to work properly.
What are the Problems of Overfilling Transmission Fluid?
There are several problems connected with the overfilled transmission fluid. The most common are rapid wear that ends up in costly repairs. Sometimes it can lead to a need for a complete transmission replacement.
Total Failure of Transmission
High levels of ATF will cause cracking of the transmission seals. It can eventually lead to transmission leaks. High levels of the ATF can also lead to high-pressure build-up, which can also lead to broken seals soon after, you will go from too much ATF to very low levels of the ATF. That will end up with a lack of lubrication and wear of the transmission system. All those factors will faster lead to complete transmission failure.
Rapid Wear and Tear of the Transmission System
The rotating gears inside the automatic transmission move and splash the ATF in the combustion chamber. If the level is high, it will cause a chemical reaction, forming air bubbles and foam in the ATF. If the ATF is foamy or full of bubbles, it won’t work as it should. The temperature will rise, and the ATF will provide insufficient lubrication.
The ATF should come between moving parts in thin layers of coolant and lubricating the system. Instead, the air pockets will lower the overall lubricating function.
High temperature and inadequate lubrication will result in faster wear and ther of all elements of the transmission. Wear of the transmission system over time will intensify, leading to destroyed transmission.
Oil Starvation & Foaming
A high lubrication level will eventually result first in foaming. As we said, the splashing and overall movement of that much fluid will create a foam. That leads to poor lubrication. It can also lead to cracks in the gaskets and seals. In one moment, you will have too much ATF, and in the next, you will suffer from the lack of ATF.
Low transmission fluid level will result in a lack of lubrication. Unlubricated metals will clash with each other creating metal shavings. Those shavings can end up in the fuel system, creating massive problems. The whole fuel system and fuel pump are in jeopardy.
Excessive Pressure Build-Up
If the level of ATF is too high, that will also create increased pressure inside transmission components. That pressure and stress, combined with the high automatic transmission fluid level, will lead to air contamination.
That can lead to two big problems – damage to the seals and the rest of the internal components. That will lead to some expensive repairs that you can easily avoid.
Overheating of Transmission
More fluid may seem better because it can do its job better, right? Well, no. Too much ATF will lead to problems with the lubricating and cooling of the transmission. The air will not be able to move around freely, and that will rise the temperature.
Check Out Signs Of Too Much Transmission Fluid:
Why Someone Adds Too Much Transmission Fluid?
Usually, when drivers think that they can replace the fluid by themselves, they think that it is a good idea to add a bit more. They don’t know how wrong they are. More doesn’t mean better. On the contrary, you should add the right amount specified by the manufacturer.
What Are The Signs Of Too Much Transmission Fluid (and Its Fix)
It is fairly easy to diagnose the signs of too much ATF. The easiest ones to identify are the high level of fluid on the transmission dipstick. Also, there are leaks from the transmission and problems when shifting gears. An overheated engine combined with strange noises from under the hood is also something to look out for.
Leakage of Transmission Fluid
Inside the transmission are seals that keep the fluid from leaking. If there is too much fluid, that will put additional pressure on those seals. Once you see drops of transmission fluid under your car, you should see what is happening. The first thing to do is to check the dipstick.
High Level On Transmission Dipstick
Some drivers regularly check the levels of all fluids. You may notice a high level of ATF when checking the transmission dipstick hole and reading from the transmission fluid dipstick. That is a sure sign that you have too much ATF.
If you haven’t noticed any other symptoms, that is great. There is no major damage to the internal parts; you can save your transmission.
Problem In Changing Gears
If there is too much ATF, that can cause stalling when shifting gears. The gears may stick and not engage properly. That can leave a strange feel in the acceleration pedal.
Weird Noise From the Transmission System
Strange noises from the transmission system are a sure sign that something is wrong. Overfilling with ATF will lead to grinding between elements of the transmission. This is one of the primary consequences of transmission overfill. That will cause faster wear and tear of all transmission parts.
Overheated Engine
Regular levels of fluid will keep the whole system from overheating. On the other hand, high fluid levels will cause engine and transmission overheating. Excess fluid will not be able to cool the system, resulting in overheating properly.
Slipping Gears
One of the issues with too much ATF is slipping gears. Too much ATF will push the gear out of its place. This is followed by a brief loss of power and, eventually, stalling of the engine. Sometimes the gears will shift erratically, and you can end up in a different gear.
With the manual transmission, you are clear about this problem. You will be left out of gear, and you will have to put the transmission back in gear.
The Smell of Something Burning
The burning smell indicates that the ATF has reached a very high temperature. That happens when there is an excess of transmission fluid inside the transmission. It can also happen if the fluid is old and worn. That can cause the seals to break, causing an additional leak.
Acceleration Problems
Foam and bubbles develop when there is too much ATF. That can cause problems with shifting gears. That will result in slower acceleration. Slow acceleration can also signify that it is time for regular transmission maintenance. Parts need to be cleaned from time to time. If the levels of the ATF are normal, you should check the whole transmission.
How To Drain An Overfilled Transmission Fluid
The process of draining the excess transmission fluid is simple. You may need additional fluid if you overdo it.
- Park the car on a flat surface and secure it with a parking brake
- Open the hood and find the transmission fluid dipstick
- Take out the dipstick and clean it with a cloth
- Reinsert and again take out the dipstick so you can check the actual level of the ATF
- If the level is above the mark HIGH on the dipstick, you need to drain it
- Place the bucket under the pan and unscrew the drain plug
- Let the fluid fall into the bucket, and then close the plug
- Measure the new level of the fluid
- If it is low, add enough to avoid overfilling. Drain additional fluid if needed.
Frequently Asked Questions
What level should the transmission fluid be?
Every car has its fluid capacity. The only way to be sure is to check the dipstick. There are low and high marks on the dipstick. The level should be between those two marks.
What does your car sound like when it has overfilled transmission?
Usually, it is a grinding, whining, or humming transmission noise. That is a noise when metal parts are rubbing each other.
Can I drive without transmission fluid?
Driving without transmission fluid is fatal for all transmission components. The gears, bearings, and all moving parts will break without lubrication and cooling. The temperature will rise, and the whole system will break down.
Final Considerations
Transmission fluid is much more important than most drivers think. That is especially the case for automatic transmissions. There are a lot of parts that demand constant cooling and lubrication. It is very important to follow through on the maintenance schedules, just like the engine oil change. The good side of an oil change is that it will signal you when it is time to change it.
Nonetheless, keep an eye on the fluid dipstick level. Also, pay attention to any strange noises or burning smells. Gears should be shifting seamlessly. If you notice any of those problems, first check the level of the ATF. If it is high, and you have trouble driving the car, visit the mechanic. You will minimize the transmission damage as soon as you do it.
