FAQ: Automatic Transmission Fluid Maintenance

automatic transmission

I receive a lot of questions from both Facebook and Youtube about automatic transmission fluid maintenance. 

Probably because most of you have already watched my DIY video regarding automatic transmission fluid change on my Mitsubishi MonteroSport. And many wonder why I didn’t do a complete automatic transmission fluid flush (dialysis procedure).

Some asks about the type of fluid or the amount of fluid to be used. Some asks for mileage details before doing any transmission service, etc. 

So to answer all your queries about this topic, I am writing this post as a guide and only resource to any transmission fluid maintenance queries that you might throw at me in the future.

Here are some of the frequently asked questions about ATF maintenance.

 

What Type of Fluid Should I Use?

The simplest answer to that is check your “owner’s manual”, nothing else. Your owner’s manual is the Bible of any type of vehicle maintenance so make it a habit to read your manual. And a lot of my answers here are going to be similar with this one.

Every vehicle is differently made from each other. With that said, they don’t use one common automatic transmission fluid brand or type. So checking the recommendation of your car manufacturer is the best thing to do. 

For example, in my MonteroSport ATF change, I used what Mitsubishi recommends which is SP3. Other types of ATF include Mercon 5, synthetic, type F and many others. So always use what’s recommended by your manufacturer.

atf brand sp3

What is Automatic Transmission Fluid Change?

ATF change is a simple procedure of replacing the existing fluid stored only in the transmission pan. But  you are not draining the entire fluid in the system as large amounts of fluid are found in the transmission itself and inside the torque converter.

It is similar to engine oil change where you drain the oil through the drain pan, then putting fresh oil back in. The only difference is that, you didn’t replaced the entire fluid in ATF change. 

There are much more advantages of doing automatic transmission fluid change. Read on to know why. 

 

When Should I Change My Automatic Transmission Fluid?

Again, see your owner’s manual for guidance.

Most of the time, your manufacturer will tell you to change your ATF between 60,000 and 80,000 mileage. This all depend on the make, model, year, size of vehicle (like cars and SUV), etc.

But some car models may require you to have an early transmission service every 30,000 miles, so you truly need to depend on your owner’s manual. 

How Often Should I Change My Automatic Transmission Fluid?

A similar question as the above and the answer to that is again check your owner’s manual.

Consult your owner’s manual and it will give you ideas when and how often transmission change should be done.

But what if your manufacturer says that your car doesn’t need any transmission fluid maintenance? There are cars that are marketed to have “lifetime automatic transmission fluid”. Does this mean that you don’t need any maintenance done in your car?

Well, not exactly. These type of vehicles are still required to have ATF change once in a while and there’s no such thing as “lifetime” when it comes to fluid. Why?

Because automatic transmission fluid gets worn out and burned overtime that’s why. So you still need to change them once you reach a certain mileage on your car. 

This type of tranny is called “sealed transmissions” and is now a common type of transmission in most modern vehicles today. This is also one way for the car manufacturers to discourage car owners from doing any car maintenance on their own. 

automatic transmission valve body

How Much Fluid Should I Use?

Again, check your owner’s manual for accurate transmission specifications such as fluid amount and brand.

For my MonteroSport, the total amount of fluid required is 9.7 liters which is a lot as my vehicle is a mid-size SUV. It would be less than that figure if yours is sedan or a crossover car.

If you’ll do your own fluid change, there are several ways to measure your fluid level accurately.

First is of course through your dipstick (for non-sealed transmission). You want to measure the level of fluid through your dipstick, I mean that’s the only reason why dipsticks are made right? 

 

Drive your car until you reach the normal operating temperature. Keep your engine idling when checking your dipstick. The fluid should reach the “warm” mark sign (other car makes only has “W” or “H” mark which means warm or hot). 

Another way is to measure the amount of fluid that you drained. For example you drained 5 liters of old ATF, then you simply need to fill 5 liters of fresh fluid into your transmission. 

Another common way is….

What is Automatic Transmission Flush?

Dialysis or ATF flush is another way of ensuring that your transmission has the right amount of fresh fluid. What does transmission flush mean?

ATF flush is a type of transmission maintenance that is commonly serviced at auto shops and dealerships. It is a process of draining and removal of old fluid within the entire system, while simultaneously filling in fresh fluid.

This is done using a transmission fluid exchanger or can also be done manually. So for example your car has 8 liters of ATF, the machine will suck or drain 8 liters (from the outlet transmission pipe) while filling in 8 liters of fresh fluid (using the inlet transmission pipe). 

atf dipstick

Should I Do Automatic Transmission Change or Flush?

Again, your owner’s manual will tell you if you are required to change the fluid or flush the entire system. 

However, most of the time manuals won’t give you any information on what type of transmission fluid maintenance for your car. 

So what should you do? 

First is to check your mileage. If your mileage is still far from the recommended maintenance schedule, then you can do either a flush or fluid change. This is common in low mileage vehicles like mine. 

But if yours is driven in a daily basis and has high mileage, then you better check your ATF color first before you decide whether you need a flush or just a simple fluid change. 

Fresh new fluid is pink or red color (the natural color of hydraulic fluids). A fluid that is darker but still has pinkish color means you need to replace it. And lastly, black fluid means that your fluid is already worn out (burned). 

 

If your fluid is still red, then it is okay to go for ATF flush. However, if your ATF is already black, then avoid flushing your ATF and settle for transmission fluid change. 

Now the question is why? Because if you have a dirty transmission, your torque converter, valve body and clutch packs are all working with burned fluid which naturally has more friction. The gunk and metal debris from your old fluid maybe the only things that are making your car drive and not slipping. 

New ATF is a good cleaning agent. So putting a new fluid into a dirty transmission will cause your tranny to slip as debris will clog the valve body and other components inside your transmission. 

So only flush your transmission if your fluid is still in good condition. If your fluid is burned, it is safer to do fluid change, not flush. Besides, getting a fresher fluid into your transmission is always a good thing.

transmission pan

Summary

There you have it! Those are some of the frequently asked questions that I get from my channel and social media accounts. So I hope you learn something here.

Below is the ATF change video of my MonteroSport which I mentioned above. This is in Tagalog language but has English subtitle. Enjoy watching!