How to Change Transmission Fluid? A Step By Step DIY Guide

Just like so many other things in your vehicle, fluids wear out with time and use and will need to be changed.

Engine oil and transmission fluid are two of the most important ones to your vehicle. Fortunately, both are fairly easy to replace yourself, and you shouldn’t need a mechanic’s help each and every time this task comes up.

Changing transmission fluid is a bit more messy than just changing your oil, and tends to involve more steps.

That’s not to say that it’s a difficult one, though. If you have the space and can follow simple instructions, you may be able to save a few bucks by doing it yourself in your driveway.

Car in a garage service shop with mechanic working on the laptop for data entry regarding maintenance tasks

If you don’t have the space to change the transmission fluid at your home or you aren’t comfortable doing it yourself, then that’s not a problem at all – you can have a mechanic do it for you instead.

They can even do a transmission fluid flush, something that is much more difficult to do correctly than a simple change.

For now, though, let’s look at everything you need to know about how to change your transmission fluid yourself.

Why Should You Change the Transmission Fluid Yourself?

The most obvious reason to do this yourself is to cut down on costs involved in hiring a mechanic to do it for you.

Parts are often more expensive at a mechanic shop or dealer, and you will have to pay more for labor as well. Dealerships are often more expensive than private mechanic shops overall.

If you are concerned about costs, it is worth doing this all on your own.

Some manufacturers suggest performing this task once every 30,000  to 60,000 miles, especially if you frequently travel in stop-and-go traffic or consistently tow with your vehicle.

If you’re the type of person who enjoys learning new skills and working with your own two hands, then you’ll get great satisfaction out of changing the transmission fluid yourself, as it’s a much messier process and slightly more involved than just changing your engine oil.

I know I have tons of fun when doing this stuff all on my own!

And as sidenote, if you’re unsure on the frequency you can check out our article on how often you should change transmission fluid in your car.

What Tools Will You Need to Change Transmission Fluid Yourself?

The first part of any do-it-yourself project is to gather the necessary equipment to help you get the job done.

The following list discusses what items you will need to change your transmission fluid on your own.

Rags

Almost anytime you do something with your vehicle, you will get dirty – and be warned from now, this can be a particularly dirty job!

The more rags you can have at your disposal, the better off you will be.

Your Owner’s Manual

Your owner’s manual is your instruction guide for everything you will need and all the steps you’ll have to take to change your transmission fluid.

It will also highlight some very important “dos” and “don’ts” during the process.

A Funnel or Oil Pump

After your transmission fluid is drained, you will have to replace it.

A funnel will be needed if you have a vehicle with an automatic transmission. Much like motor oil, there is most likely an opening under your hood, sealed with a dipstick in which you can pour new transmission fluid.

If your vehicle has a manual transmission, you will most likely have to pump gear oil or transmission fluid back into the transmission through a plug on top of the transmission housing.

Jack

Regardless of whether your vehicle has a manual or automatic transmission, you will have to jack up the front part of your vehicle to crawl underneath and release the transmission pan or drain plug.

Jack Stands or Wheel Ramps

After you have jacked the vehicle up, you will need a way to keep it there for the duration of the change.

If you have wheel ramps, you will simply need to drive the vehicle onto the ramps, put the emergency brake on, and chock the rear wheels.

You can also use jack stands for this purpose.

If you decide to do that, here’s a guide we put together about how to use jack stands, as well as another guide we wrote about some of the best jack stands out there you can buy and use for vehicle related work.

Wheel Chocks

While the vehicle is jacked up in the front, you should use wheel chocks for the non-lifted end of the vehicle as an added safety precaution.

This will ensure the vehicle stays stationary while you are underneath it.

A Towel or Some Other Kind of Tarp

Because this can be such a messy process, you should lay down a towel or tarp to prevent any spilled fluid from getting into the surrounding environment.

A Large Oil Catch Pan

Transmission fluid is considered to be hazardous. You will need to collect the old fluid in a large catch pan and take the used fluid to be recycled.

A wide catch pan is recommended to catch as much fluid as possible.

Torque Wrench or Ratchet

To drain the transmission fluid, you will need to unbolt the transmission catch pan in an automatic transmission, or release the drain plug in a manual transmission vehicle.

Both will probably require a good bit of force to loosen and tighten when you are finished.

Gloves

Just like rags, gloves are always helpful during any messy automotive maintenance job.

Unlike rags, though, gloves will protect your hands from getting burned, as a transmission fluid drain works best when the engine has been running and the fluid is hot.

Cleaning Solvent

Once the transmission pan is taken off, it is a good idea to clean it out, as small bits of debris might build up on the bottom.

Water can cause parts damage from oxidation, so a cleaning solvent or specifically engineered transmission cleaner is necessary.

Screwdriver

When the pan is finally unbolted or the drain plug unscrewed, there could be an old gasket or seal that keeps holding the removable part in place.

If this happens, a screwdriver can be used to gently pry off the pan.

New Gaskets

Once a pan or bolt is removed from the transmission, it is always a good idea to replace the gasket which was previously used to seal everything.

Gaskets and seals are often the first parts of any vehicle to go bad, since they are made from rubber and plastic rather than metal.

Transmission Fluid

This task wouldn’t be complete without the actual transmission fluid.

Make sure you check your owner’s manual to see what kind your vehicle requires, and have a look at this article to find out what some of the best transmission fluids of today are.

How to Change Transmission Fluid: A Step by Step Guide

The change process in and of itself is not all that complicated, but it is usually cumbersome and messy.

Let’s look at what you will need to do to perform one properly.

Bring the Vehicle to Normal Operating Temperature

Most fluids flow easier when they are warm.

Transmission fluid is the same, therefore it will flow easier (and more fluid will be drained) when it is warmer.

You can warm the transmission by idling the vehicle for a few minutes, or by driving around the block.

Jack the Vehicle up and Secure It

You will need to access the transmission pan or drain plug from underneath the vehicle.

Use a jack to raise the front of the vehicle, use jack stands or wheel ramps to keep the vehicle raised, and chock the rear wheels to make sure the car doesn’t inadvertently move while you are working.

Loosen the Transmission Pan in an Automatic or Drain Plug in a Manual Transmission

Once you locate the pan (if you have an automatic vehicle), or the drain plug (if you have a manual transmission vehicle), you will need to remove it.

Place your fluid catch can under the pan or plug, then use your torque wrench or ratchet to unscrew the pan or drain plug.

Allow the Transmission Fluid to Drain

Once the pan or plug is removed, align your fluid catch can so that as little fluid as possible leaks onto the surround ground.

If your vehicle has a transmission pan, unscrew one side slightly more than the other so that the fluid has a more concentrated flow.

Remove the Transmission Pan

When most of the fluid drains and the flow rate is reduced, you can fully remove the pan.

Most manual transmission vehicles don’t have a removable pan.

Check and Clean the Transmission Pan with Cleaning Solvent

Once the pan is removed, check it for unwanted debris.

If you see metal shavings in the pan, you may have transmission damage and should consult a mechanic. Otherwise, the pan should be free of foreign material.

You should always clean the pan or plug with cleaning solvent before replacing it after the fluid has completely drained.

Both transmission pans and plugs are magnetized to catch any foreign metal that would otherwise get caught in the transmission gears and cause extensive damage.

Install the Transmission Fluid Filter

Many transmissions have filters in them, much like oil filters.

These should also be replaced to make sure no leftover material is transmitted into the new fluid.

Replace the Transmission Pan Gasket and Pan or the Filler Plug Seal

Once all the fluid is drained from the transmission, you will need to replace the pan or drain plug to prevent the new fluid from leaking.

Replace the gaskets of the pan or o-ring on the plug to form a protective seal, and apply a layer of grease to each gasket, further preventing the possibility of future leaks.

It is recommended to use grease to line the gaskets or o-ring plug seal rather than sealant, though sealant can be used if grease is unavailable.

Refill the Transmission Fluid

Reference your owner’s manual to see how much transmission fluid your vehicle holds.

For automatic transmissions, use the funnel to pour the necessary amount of new transmission fluid into the filler reservoir under your hood.

For manual transmissions, an oil pump is usually needed to pump new gear oil into a hole on the top of the transmission housing.

Turn the Vehicle on and Let It Idle

After the new transmission fluid is added, turn your vehicle on and allow it to idle.

This will allow the new fluid to circulate throughout the transmission housing and coat all gears and bearings within the transmission.

Check the Fluid Levels

In an automatic vehicle, you can check the fluid levels while it is idling by pulling the transmission dipstick. Add more fluid if necessary.

In a manual transmission vehicle, you will have to turn the vehicle off.

Your owner’s manual will detail how to check transmission fluid levels, but normally, you can check it by placing your finger into the filler hole to see if any fluid gets onto your finger.

Check for Any Leaking

After you have added fluid and checked fluid levels, examine the areas around and underneath the vehicle for any leaking.

Test the Transmission

If there is no leaking, lower the vehicle from its stands, get inside, and test the transmission by shifting through several gears.

If the vehicle shifts correctly, the job has been successfully completed.

For more useful information that could come in very handy, watch this video.

 

Where Should You Go If You Don’t Want to or Can’t Change the Transmission Fluid Yourself?

Any dealer or mechanic shop will be able to perform this task should you not have the space, the confidence, or the tools necessary to do it yourself at home.

As an added bonus, shops will also be able to perform a transmission flush for you while at it, which is much harder to do by yourself than just a fluid change.

This can be very beneficial, but you should know that it isn’t always necessary.

How Much Will a Transmission Fluid Change Cost?

Most transmission fluid changes at a dealer or shop will cost between $80 and $250, with an added transmission flush costing much more.

If you choose to do it yourself, you will only need to buy the transmission fluid and filter, providing you already have all the necessary tools you’ll be using throughout the process.

If you don’t have the tools, however, it may cost about the same as a shop if you have to buy vehicle jacks, wheel chocks, and other necessary tools.

With that being said, it may be very worth the cost of buying all the tools right now, especially if you plan on performing future changes yourself.

Plus, you never know what future car maintenance tasks you’ll choose to do yourself, for which you’re also likely to need many of these tools as well.

Are There Any Other Tips I Should Know About?

Many of the newest vehicles come equipped with sealed transmissions and “lifetime”, no-change transmission fluid.

To find out if your vehicle has anything like this going on, be sure to consult your owner’s manual to see if it has a transmission fluid section, and check whether or not that’s the case.

If it does not, you will need to consult your dealer for any issues you might have with performing this car maintenance task on your own at home.

Remember to always check your owner’s manual first for any special information you might need to know when you should change your transmission fluid, including the type of gasket sealant or lubricant you should be using to seal the gaskets.

If you are taking on this task for the first time ever, you should be able to find transmission fluid change kits to make good use of.

These come with several tools necessary to complete the job, and will help you get off to a great start in your DIY maintenance journey.

Last but certainly not least, always remember to replace and re-apply your transmission pan gasket. It is an easy item to forget, but it will prevent leaks and future issues!

Conclusion

Changing your transmission fluid when it needs to be changed is a very important task to complete, or else you’ll risk facing the repercussions down the line – ones that come in the form of wasted time and money lost.

Doing it yourself can be rewarding, can save you the hassle of scheduling an appointment, and is very likely to save you some money.

If you don’t have the tools or the time to do it yourself, though, then your mechanic can easily perform this task for you.

In certain cases, you might not even have the choice to change the transmission fluid in your vehicle by yourself.

Many modern vehicles have advanced transmissions, and don’t even have transmission fluid changes outlined in the owner’s manual.

Regardless of what vehicle you might have, changing the transmission fluid – if your vehicle allows – is a pretty straightforward task, and knowing how to do it is a good skill to have.

Hopefully, after reading this guide that we’ve put together, the process now seems to be much more straightforward than you thought it was at first. It really isn’t all that difficult!

I've had a passion for cars since 8 years old, and been a subscriber to Auto Week magazine since my 10th birthday. Ever since I turned old enough to drive, I have driven as many vehicles as possible, while teaching myself how to perform maintenance and upgrade work on every vehicle I've owned. For the past 10 years, I've been honing my skills as a vehicle hobbyist, in recent years also enjoying writing car reviews, opinion articles, vehicle how-tos, car-buying guides, and even provide individual consultations for those who need car-buying advice. In addition to writing for Vehicle Scene, I currently write for Autolist, and also own and operate my own vehicle blog website, The Unlimited Driver.

Leave a Comment