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What’s The Difference? Transmission Fluid Flush Vs Change
A car’s transmission is one of the most important parts of a car. That’s why it’s important to service your transmission from time to time by making sure that you are following vehicle manufacturer guidelines to change your transmission fluid at regular intervals.
But should you have your transmission fluid changed or flushed when it comes to servicing your transmission? A transmission fluid change is when the old transmission fluid is drained out of the transmission and new fluid is then poured into the transmission. With a transmission fluid flush transmission fluid is flushed throughout the transmission in an effort to clean out any gunk or debris.
But which option should you go with a transmission change or a flush? Which is the safer option? And when should you not replace your transmission fluid at all?
What is Transmission Fluid?
Transmission fluid sits inside of your vehicle’s transmission and lubricates the different parts and mechanisms to allow them to move smoothly while your vehicle is in motion and you are changing gears. 
Most transmission issues are going to be caused by the transmission overheating which in turn will cause excessive wear on the clutch disks within your transmission. As your clutch disks get worn down over time the material from the clutch disks gets put into the transmission fluid decreasing its cooling effectiveness.
That’s why it’s important that you change your transmission fluid regularly to keep your transmission fluid clean and allow it to do its job effectively.
Transmission Fluid Change vs Flush – What Is The Main Difference?
The main difference between a transmission fluid change and a flush is the amount of transmission fluid used during the process. With a transmission fluid change, the old transmission fluid will be drained and new transmission fluid will be put into the transmission but just enough fluid to fill up the transmission to the proper level. Most transmissions will take anywhere from 3-6 quarts to refill after they have been drained.
With transmission fluid flushes a lot more transmission fluid is used during the process, typically anywhere from 10-12 quarts of transmission fluid. The point of a transmission fluid flush is to push new transmission fluid throughout the transmission to thoroughly clean the inside of the transmission. With automatic transmissions old transmission fluid can remain in the torque converter and won’t be drained out by draining the transmission fluid.
To properly remove all old transmission fluid in an automatic transmission (without flushing the transmission) you have to drain the transmission fluid, refill the transmission fluid, go for a drive, and then drain the transmission fluid again (this process would be done up to three times) to remove all of the old transmission fluid.
Manual transmissions don’t have a torque converter and therefore wouldn’t need to go through this same process in order to remove all of the old transmission fluid from the transmission.
Transmission Fluid Change
When talking about the differences between a transmission fluid change vs flush you first need to know what both are. When you change your transmission fluid in your vehicle you are essentially removing the old transmission fluid from your transmission and replacing it with new transmission fluid.
This is a pretty straight forward process on manual vehicles but on automatic transmissions they have a part called a torque converter inside of them that can hold onto a few excess quarts of transmission fluid.
That is why on automatic cars if you are replacing the transmission fluid it’s a good idea to change out your transmission fluid in small batches. If you are planning on going this route it may not be a bad idea to use inexpensive transmission fluid for the first couple of transmission fluid drains to help keep the overall costs of the project low.
To learn more about how to change the transmission fluid on your vehicle yourself check out the video below that shows step by step how easy it is to change the transmission fluid on most vehicles. If you plan on changing the transmission fluid on your car I’d look up a video lower down in this article that shows you how it should be performed.
Transmission Fluid Flush
Some mechanics or service shops will advertise that they can flush your transmission fluid from your vehicle eliminating the process of having to drain and then refill your transmission fluid multiple times. The downside to going with a transmission fluid flush over a change is from the potential harm that it can cause to your transmission.
During a transmission flush, fluids are pumped into your transmission to try to force any old clutch particles out of your transmission to clean out the inside of your transmission. This can cause the fluid to get sent to areas that it should not ultimately ruin your transmission.
With as expensive as your transmission is to repair you want to take care of it to not do any unintended damage to it which can happen from flushing your transmission fluid.
You would really want to check your owners manual to see which method they recommend you go with. Some vehicle manufacturers like Ford call for having your transmission fluid flushed, while Honda usually calls for having their transmission fluid changed.
Transmission Fluid Change vs Flush – Which Should You Go With?
So which type of transmission fluid change do I think you should go with? Having your transmission fluid changed or draining the old transmission fluid and replacing it with new transmission fluid is definitely the safer option.
With transmission fluid flushes fluid will be forced throughout the transmission and can cause debris in the transmission to circulate around which can clog up parts of your transmission. With that said having your transmission fluid flushed can potentially cause more problems to your transmission than draining and refilling the fluid.
The safer bet is changing your transmission fluid by draining it, refilling the transmission with more fluid, taking the car for a drive, and then repeating the process of draining and refilling the transmission fluid.
How Do You Change Your Transmission Fluid?
I usually learn better by watching a video of what I am trying to do. If you wanted to check out a video showing the whole process of changing out automatic transmission fluid on your vehicle if you wanted to check it out.
This video will explain the process of a transmission change vs a flush and how to change the transmission fluid on a truck. If you plan to change your transmission fluid yourself I would recommend looking up a Youtube video showing how to change the transmission fluid for your specific vehicle.
Can A Transmission Flush Damage Your Transmission?
Yes, having your transmission flushed can sometimes cause more harm than good but this typically only occurs with transmissions that have already been neglected to begin with.
The idea behind having a transmission fluid flush is that the transmission fluid is forced throughout the transmission in order to clean out any debris or particles that may have settled in the transmission over time with use.
As transmissions are used particles of the clutch or clutch packs can mix into the transmission fluid and then get stuck in the crevices of the transmission. Since the transmission fluid is being forced throughout the transmission it can clean things out and knock things loose within the transmission which has the chance to plug up other areas of the transmission that may have not had a problem, to begin with.
Transmission fluid flushes can also clog up transmission fluid filters within a transmission (if your car’s transmission has one). To learn more about how changing your transmission can damage your transmission check out the video below.
Can Changing Your Transmission Fluid Cause Damage?
The answer is it depends, let me explain. Changing your transmission fluid can cause your transmission to start slipping if the transmission fluid in the vehicle has never been changed. If the regular maintenance schedule for the transmission fluid has been maintained then changing the transmission fluid in your car shouldn’t cause any damage to the transmission or cause it to slip.
To learn more about why you shouldn’t change the transmission fluid in an old car if it’s never been changed before check out my other article (link here).
Change Filters And Gaskets If Applicable
When changing or flushing your transmission fluid you would want to go ahead and change any filters or gaskets within the transmission if possible. Some transmissions are designed to have filters that can be changed out periodically.
The main job of a transmission filter is to filter debris and clutch pack particles from the transmission fluid so that the debris particles don’t keep circulating throughout your transmission. That way your transmission fluid stays clean and is able to keep the internals of your transmission well lubricated.
Transmission Fluid Change Vs Flush – In Conclusion
Now you should know more about your transmission than you did when you first started reading this article. Hopefully, this article was able to answer your question of what is the difference between a transmission fluid change vs flush.
Now you have the knowledge to decide which is going to be better for your vehicle and if you should leave your transmission fluid as is or change it out periodically.