How to Change Automatic Transmission Fluid and Filter (COMPLETE Guide)

How to Change Automatic Transmission Fluid and Filter (COMPLETE Guide)

Hey guys, ChrisFix here, and today, I’m going to show you how to change the transmission fluid and the transmission filter in your car or truck in this case. We’re working on a 2001 Mazda pickup truck. It’s the same Chassis as the Ford Ranger, Ford Explorer, and many other Fords and Mazdas, but even if you don’t have a Ford or Mazda, this process is going to be very similar for most makes and models. There might be little differences here and there, But just like changing your engine oil the process is relatively similar. So after watching this, you’ll be able to change the transmission fluid for your vehicle. So there are five main steps for changing your automatic transmission fluid. One: get the vehicle in the air and drop the transmission pan. Two: replace the filter. Three: replace the transmission pan gasket. Four: install the pan. Five: add the fluid. It’s that simple. So let’s get started. This job is going to be an automatic transmission fluid change, not a flush. With a flush most places use a machine to pump out all the old fluid and add in brand new fluid, but they don’t remove the drain pan, so typically, the filter isn’t replaced. With a transmission fluid change, you drop the transmission pan so you can get access to the filter and replace the filter—which is exactly what I want to do. But remember—with the fluid change you only remove about half of the old fluid. If you aren’t sure what to do check the owner’s manual, which will tell you if you should change or flush the fluid in your specific vehicle. It’ll also tell you how many miles you could go before you need to change or flush the fluid and. Finally, check your transmission fluid fluid in good condition is bright pink, but if your fluid looks black, smells burnt, or has metallic specks in it, your transmission is probably damaged, and in that case, do a fluid change since it only removes half the old fluid, or just leave it alone. But don’t flush the fluid because flushing the fluid is going to remove all that suspended clutch material and that could cause your transmission to slip. So now let me show you how to change transmission fluid so you can prevent damage to your transmission. And here are all the tools you’re going to need. As always, use some gloves and safety goggles to protect your hands and eyes, and there really aren’t many tools that you need for this job. We have a 13 millimeter, ten millimeter, and an extension for our ratchet. Torque wrench, scraper for the gasket, and also an abrasive pad for the gasket to clean it off. A funnel and some brake clean, some towels, and you’re also going to need some type of catch can to catch all the fluid that’s draining out and then I like to put down a tarp or some cardboard on the ground so I don’t get oil all over my driveway. So those are all the tools, now we need to make sure that we’re using the correct transmission fluid, and to do so, consult your owner’s manual and see what fluid is required. If you look over here Ford requires the use of Mercon©V. Now that varies from vehicle to vehicle, so make sure you check your owner’s manual, because if you use the wrong fluid, you’ll cause transmission damage. So for my truck I’m using Mercon©V, and we’re also replacing the transmission filter since I don’t know the last time it was changed, or if it was ever changed. Plus, when you get your filter, it comes with the gasket you need to seal the transmission pan after you drain the fluid. and that just about covers everything you need to know so let’s begin. All right. Step one. We want to lift our vehicle so we could drain our transmission fluid. In this case, I used ramps But you could use jack stands if you want. After the vehicle is safely lifted and the wheels are chocked off, we could slide the tarp and catch can under the truck. Now we need to be able to find where the transmission pan is. So going from the front of the car as we move backwards, you can see the front crossmember, the front differential, the oil pan, the catalytic converter, and then the transmission pan. Now since we don’t have a drain bolt, what we’re going to do is we’re going to do a controlled leak to drain our fluid. And what I mean by controlled leak is we’re going to remove the rear bolts here completely, but leave the front bolts in so our pan comes down at an angle and then when it comes down at an angle the fluid’s going to leak out the back right into our drain pan. To remove this transmission pin, there are eighteen bolts surrounding the whole pan. So I’m going to start with the rear ones here and loosen them all the way. And these bolts should be easy to remove with a normal ratchet—no breaker bar needed. And that’s one, two, three, four, and five. So with the rear bolts removed, I notice the drips are leaking down on the frame and off to the side which is going to make a mess. To combat this problem grab a piece of tinfoil which is going to allow us to funnel the leak and prevent it from getting all over the frame. Alright now let’s remove the side bolts and the ones on the other side as well. Go from side to side and now I’m going to be using this universal joint extension for this tricky bolt hidden behind the catalytic converter. Right back here. That was easy enough. And as I loosen this front side bolt, the pan should tilt. And there’s our controlled spill. And as that leaks out, I’m going to remove that bolt. Good! With most of the fluid removed, I’m going to get rid of this tin foil. And then let’s completely remove the final two bolts and as you do this make sure you support the transmission pan. And that’s one, and that’s the other. So now we can lower the pan. And this pan just simply slides out. And that’s the end of step one. Step two: We want to replace the filter. So to remove the filter, there’s one bolt right here—it’s a 10mm— that’s holding this filter in. So all we have to do is remove that and that’ll drop out. And just like all the other bolts that we’ve been removing, this one is going to be really easy to remove. Now just pull down on the filter and it pops right out. Here’s a very helpful top tip. You see all these bolts up here? These bolts hold the transmission valve body against the transmission. Due to vibration over time, some of these bolts become loose and it’s important that they’re tight. Because they compress a gasket which holds fluid pressure and that pressure gives you crisp shifts. So check this out—you see how I can turn my ratchet and easily turn this bolt? Well snug all of these bolts to eight foot-pounds. Don’t over tighten them. If one’s already tight, leave it because that’s fine. Just move on to the next one try to start from the middle and move outwards in a crisscross pattern which will seal the valve body against the transmission and this will prevent problems with shifting in the future and it might even make your tranny shift more crisp and just better overall. So with those tightened down, let’s go replace the filter. So here’s our new filter and here’s the filter we just removed from the transmission. And check this out— there’s a big crack, and that’s not good because the filter is what sucks up the fresh fluid into the transmission and with that hole, it’s leaking suction. So it’s good that we’re changing this out. And make sure you stay tuned to the end of the video because we’re going to cut open this filter and see if there’s anything inside. Whenever we replace parts you want to make sure that the parts look identical so match them up, make sure they look the same. The reason why I always say compare the new part to the old part is because of this: I ordered a transmission filter and they sent me this one. And if we compare this, well, right away, we could see that it doesn’t have that spout. The spout is for my deeper transmission pan so it could suck up the fluid. So if I installed this one, I could have caused damage if no fluid was getting sucked up. So that’s why you always just take a few seconds and compare the old and new parts. All right. So let’s get the old one out of the way and work on this new one. For the new one, we’re going to install the O-rings and what you want to do is you want to get some of that transmission fluid, get the O-Rings, and just lube up the O-rings. Small one goes here. Fits on just like that. And the big one snaps right on here. Just like that. And this is all ready to get installed so let’s go and install it. All right—back under the car, let’s install our filter. All we do is line each fitting up, and push it in to seat the O-ring. Now, tighten the filter bolt down. Always hand tighten first because this prevents cross threading. And once you tighten it, this gets torqued down to eight to ten foot pounds. Good! And step two is complete. Let’s move on to step three. Now we’re going to install our brand new gasket on the oil pan, but first, we need to get our oil pan and remove the old gasket. Now this gasket is a rubber one, so it should come off pretty easy. And if yours doesn’t come off easy, I suggest you use a plastic scraper, not a metal one. A plastic one isn’t going to gouge the metal. You could do as much as you want here and nothing is going to happen to this metal. If you use a metal scraper, then there’s a good chance that you might gouge the metal, might cause a little scratch or something, and that’s enough for fluid to seep out and over time cause a leak. And you don’t want that. Before we clean the pan, in most pans you’ll find a magnet designed to remove metal filings from the fluid. And this magnet has a ton of tiny metal pieces on it, which is fine. What we don’t want to see or any big pieces, but again, this looks normal. So to clean this we want to get some brake clean and we’re going to spray it down. Now I’ll be using a bucket so we can keep everything nice and clean and just spray down the whole thing with brake clean. All that dirt and grime is coming right off. And after we spray it down a little bit, we could take our towel and just clean it out. Alright, that looks pretty good. Now what we need to do is we need to clean this mating surface here. Get one of these Scotch-Brite™ pads that’s slightly abrasive, and then all you’re going to do is clean it up. You want to make sure all the gasket material and dirt is removed from the surface because any leftover gasket material will cause a leak. Then do a final spray to clean this up—and look at that—nice and clean. I also cleaned the outside, but as you guys know, this isn’t all. I like to go overboard. Primer. Paint. Now obviously you don’t need to paint your transmission pan, but I decided it would be a good thing to do since I have it off. So now that that’s dry, let’s go install this. Now what we want to do is we want to use a grease along the edge. I’m going to be using silicone paste, and what that’s going to do is it’s going to make that surface tacky. So when you put your gasket on it won’t move around—it’ll hold it in place. So just make sure all the holes are aligned and check this out—this holds itself in so it’s not going anywhere. Normally this gasket would fall right off, but with just a little bit of grease your life is that much easier. If you have a paper or cork gasket, I recommend using a gasket adhesive which is going to help the gasket stick and prevent leaks. Another thing I want to mention is that we’re going to be reusing these bolts, so you want to make sure the threads are clean, you want to make sure that there’s no gasket adhesive on here, and I just hit them with some brake clean and all the dirt came right off. And this is all ready to get installed, so let’s go put it in. Before we install the transmission pan, don’t forget under the car we also want to clean the mating surface on the transmission so it’s clear of any gasket material. So use your abrasive Scotch-Brite™ sponge and clean the whole perimeter. If you need, use a plastic scraper to get the remaining gasket material off, but this was pretty clean, and I don’t need to use it. And with that surface clean, we’re done with step three so let’s move on to step four. For this step we’re installing the transmission pan. It’s pretty simple: just line it up and make sure you don’t move the gasket by mistake. Once you get it lined up, press the pan against the transmission so the gasket doesn’t move, and start hand tightening those bolts in. For now only hand tighten the bolts to barely compress the gasket. The order you tighten the bolts in doesn’t matter while you’re hand tightening them, but it will matter once we start torquing them down in a couple of seconds. So get them all hand tight and don’t use a ratchet this step because that’ll tighten them too much. So now we have all the bolts in around the perimeter of our drain pan, and they’re just barely compressing the gasket. Now we want to squeeze the gasket to prevent leaks. But we’re not just going to squeeze it by tightening up the bolts in whatever order you want to go on a crisscross pattern for each bolt so it compresses the gasket evenly. Most of the time you want to start from the middle and I’m going to use this bolt to start. And if it helps you, I wrote down the sequence so you know to order to go in, because I have a feeling I might lose track of what bolt I need to tighten next. So you could always just reference this. All right, let’s get the bolts torqued down. These bolts need to be torqued around 10 to 15 foot-pounds, and I’m going to be using a crisscross pattern like I explained before. Just like how you tighten the lug nuts on a wheel in a star pattern. I’m going to include a link to the tightening sequence diagram in the description so you can use that as a reference. I have to use a universal joint socket for that hard-to-reach bolt, and I’m just going to torque it down by feel since torque wrenches aren’t really accurate with universal joint extensions. Good. Just two More bolts to torque. Alright, so everything is all torqued down, and that’s the end of step four. Now we’re on our last step—step 5. Let’s go fill ‘er up with fluid. Now we need to figure out how much transmission fluid we need to fill the transmission completely, but not overfill it. So to figure out how much fluid we need to add, let’s see how much fluid we actually drained out of the transmission. And what we’re going to do is we’re going to use one of these old oil containers that have the markings on the side here and with no fluid in this container, it’s going to easily tip over, so make sure you support it. And carefully fill the old oil container and try not to make a mess like I just did. The good thing is the box will contain the mess I made. Now if we take a look at where we’re at, we’re right here, so there’s three quarts, there’s three and a half quarts, so we want to put three and a half quarts in and then take our measurement. And this is a really easy way to figure out how much fluid we removed so now you know how much fluid we need to add. Our drain pan had three and a half quarts of fluid, so we have four bottles here, each is a quart. Now let’s go and fill up our transmission. You fill your transmission through the dipstick hole, and if you don’t have a dipstick, there’ll be a fill bolt somewhere on the top of the transmission. With the funnel in place, I want to add three and half quarts of transmission fluid to replace the fluid we removed from the drain pan. Once the transmission is filled, remove the funnel and put the dipstick back in. Now we just need to go start the car. And then back down the ramps. With the car off the ramps on level ground we’re going to shift through the different gears, we’re going to go to each one of them, and then we’re going to let the engine run for about two minutes, three minutes, let the transmission heat up, let all the fluid circulate, and then we’re going to check our fluid. All right, we went through the different gears, we let the engine and transmission warm up a little bit, it should be warm enough to go check the transmission fluid level. In this vehicle, the car has to be in idle and the transmission has to be warm for you to check the fluid, so we’ll leave the car running and let’s go check the fluid. The fluid is supposed to come up to the batched area, but it’s just barely on the tip of the dipstick, so we have to add some more. I’m going to add the other half a quart and recheck the level. After adding that half a quart, let’s see where we’re at. And this is perfect. You can clearly see the fluid is right in the middle of the dashed area. Beautiful. Now let’s shut the engine and check for leaks. So now you want to go back under the car real quick and just check for leaks and be careful the exhaust is now going to be hot, but if we look here, we look around the perimeter. I don’t see any leaks. So that’s a job well done. So there you go that’s an in-depth guide on how to replace the transmission fluid and the filter. It’s easy to do and it’s worth every penny because transmissions are not cheap. This transmission holds 10 quarts. And we replaced four of those quarts, so we changed out almost half the fluid. Plus, we got a new filter in there and speaking of filter. Let’s go check out the inside of that old filter. And here we go. Just pry it apart. So the outside the filter looks pretty good. Let’s see if there’s anything trapped on the inside. And check this out—there are tons of small metal fragments and a large one here. So that goes to show you how important these filters are because you wouldn’t want these metal pieces running through your transmission. And there we go, hopefully the video was helpful, and if you aren’t subscribed, consider subscribing for new how-to videos every week. Up on the screen are related videos like how to change your engine oil. And as always, I link all products and tools in the description so you could easily find them.

About the Author: Michael Flood


  1. Hey Chris. I need to change my inner and outer tie rods driver and passenger sides on my wife's 04 Mitsubishi endeavor xls. Is this something I can do myself? I don't own an impact and I just have standard tools. Should I be better off taking to a mechanic?

  2. Nice video. Thank you. Can you please tell me if draining the transmission fluid from the radiator is a good way to change the rest of the transmission fluid, or possibly prevent he mess I am about to make in my driveway. It seems to me that if I cut the metal lines, add rubber extensions, then start the engine I could let the transmission pump most of the transmission fluid out. I believe that is how the shop does a transmission flush. Have you, or anyone else tried this? Thank you.

  3. Great video and I really love the style. I just found your channel and have used it for many different references. I always hit the like button as well.

  4. Hey Chris, can you make a video how to flush transmission fluid ? If it’s possible to do it at home , I have a Toyota Corolla 2005 and just replaced the transmission not to long ago and I really want to make it last and keep up with the maintenance Once it reaches about 50,000 miles I’d figure I’d flush it , but should I flush it or just replace it ? If you can make a video about flushing the fluid I’d do much appreciate it , thanks Chris. I don’t why we’d be without guys like you.

  5. First I want to say I have a lot of respect for U and what you do!! BUT when dealing with the trans mittion it should be level in order to get the most of that burnt up shit out and get true readings.. Plus your drain pan should be a numbered pan so you know exactly how much fluid came out, Not a Baking sheet pan.. But do you Bo…..

  6. Thank you, thank you, thank you for your videos!! They are so much help! I didn't know much about cars but I have watched many of your videos and feel like I can open a shop now lol I have a 96 Dodge ram van and I have done all the maintenance myself thanks to you sir!

  7. ChrisFix very good videos always step by step Way to go buddy also starting my own channel it would be an honor to have a guy like you subscribed to my channel and leave a comment…🤝👍🏼👍🏼👍🏼👍🏼

  8. You're videos and Haynes manuals have saved me thousands. Thank you Chris!

  9. Hey Chris I’m getting ready to do the pan drop and fill in my 02 ranger with the 5R44E and I think we have the same trans lol can’t wait to get it done.

  10. Hey Chris or anybody with the answer.. Question for you, it was not mentioned in the video, unless I missed it.
    When adding transmission fluid, should the car be running in the idle ? Or turn the car off ? I noticed first you did it with the car off, then you added more with the car on.

  11. Ford Expedition uses same fluid you use forMazda? Can I just pump out the old fluid and refill it equal to how much sucked out?

  12. I haven't changed my ford t fluid,Since 2011 so its been 9 years and 20k miles total.The fluid is still pinkish color, should I change it soon?

  13. Hey man quick question why do people say it’s not good to change your trans filter? I need to change mine but I need a second opinion

  14. After changing a transmission fluid once the next time you change it does it change the same 50% as the first time? I bought a car without really checking it and the fluid is really dark. I have problems going in gears and a mechanic told me to change it every 2-3 weeks about 3 times. It has turned a little red but still dark. So Not sure if I’m just spending money changing the same 40% I just changed prior or if in time it would start to get more red.

  15. Question: Can I use AmsOil’s transmission fluid with the same specs? And is it safe/or even worth the coin ?

    06 ford ranger 4L automatic trans.

  16. Please Chris ; will you make 3 min video to tell us how ATF fluid runs inside the Auto transmission to torque converter to heat exchanger radiator throw the lines.
    I mean the Fluid circuit: 1st oil pan to 2nd pump to 3rd , 4… to oil pan again.
    Easy video to you , and much useful to many off us.
    Thanks a lot.

  17. I really enjoy your videos.
    My stepdad was an awesome mechanic, and looking back I wish I had learned more about cars when I was younger. Your videos are fantastic for someone who wants to learn about cars and how to maintain them yourself.
    Thanks for being so detailed, with excellent explanations and visual aids. This information is so valuable and you make it so easy to follow.
    Keep up the good work 🙂

  18. Hey Chris, I'm a recent fan and have been watching all these videos. I'm nothing that comes close to a mechanic, yet I'm feeling like I can tackle some of the repairs.

    I had a suggestion, is it possible for you to tell us how much are we saving when we do these projects are selves, compare to shop.

  19. hi chris, i did notice that other videos show " flushing the torque converter and cooler system." thus replacing 99 percent of the old transmission fluid with new fresh red transmission fluid. Im wondering if just dropping the pan and replacing only what is in the pan is sufficient…what da ya think?

  20. Can you do a full system flush on a CVT and filter replacement it has 2 filter that would be a really good video because not to many people did a good video so I would love for you to do it one day

  21. Chris have a question. I have an 02 honda civic just bought doesnt drive. When i turn it on and put into any gear i get nothing from the tranny. Have done OBD scan and it is clean. I think it may be the tranny pump gave out so that is whybit isn't shifting at all. Any info would help. Thanks love the videos

  22. How are you going to get the rest of that oil out? do you run new transmission fluid through it again until you start flushing out when you transmission fluid?

  23. Just call the Mazda dealer and they definitely do not take the steps. The guy says we just drain it and fill it and we do not mess with the filter to prevent damage.

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