How Often To Change Transmission Fluid and Other FAQ

Reviewed by

Anthony Harlin, ASE Certified Master Automobile Technician

Technical Reviewer at CarParts.com

Written by CarParts.com Research Team - Updated on March 23rd, 2024

Reading Time: 6 minutes
Summary
  • Transmission fluid lubricates the transmission system, preventing metal parts from grinding against each another.
  • Transmission fluid is usually changed every 60,000 to 100,000 miles in automatic vehicles and every 30,000 to 60,000 miles in manual vehicles.
  • You should check your transmission fluid when you hear grinding noises from your transmission, when the engine overheats, or when you have difficulty shifting gears.

How often do you change your transmission fluid? Every three years, five years, or perhaps never? 

Unlike engine oil changes, vehicle owners often forget about changing their transmission fluid, even if it’s an equally important service that keeps their vehicle in top shape. Every vehicle needs a transmission fluid change every now and then, even those with “filled-for-life” transmissions.

Transmission fluid is a lubricant that keeps your transmission system’s parts from grinding against each other when the engine is running. It also cleans your transmission’s gears, bearings, and other metal parts while preventing your gearbox from overheating.

Because it plays such an important role in making sure your gearbox functions properly, it’s important to know how often to change your transmission fluid and how this can differ depending on whether you own an automatic or a manual vehicle.

How Often To Replace Transmission Fluid

There’s no straight answer if you’re wondering how many miles you have left to change your transmission fluid, but it certainly doesn’t hurt to keep track of it when servicing your transmission more often is a lot cheaper than replacing the transmission entirely.

Transmission fluid is a lubricant that keeps your transmission system’s parts from grinding against each other when the engine is running. It also cleans your transmission’s gears, bearings, and other metal parts while preventing your gearbox from overheating.

Automatic Transmission

If you’ve driven both an automatic and manual vehicle before, then you’ve probably noticed how automatic vehicles can be easier to handle than manual vehicles. This is because automatic transmissions do a lot of heavy lifting. They transfer power from your engine to the wheels, which generates more heat for your automatic transmission fluid (ATF) to cool down.

In other words, automatic transmissions work harder than manual transmissions because they do all the shifting for the driver.

While most manufacturers recommend an ATF change every 60,000 to 100,000 miles, you might want to check your transmission fluid every 30,000 miles just to be sure.

Manual Transmission

Wondering how often you’ll need to do a manual transmission fluid (MTF) change? Well, the answer can still vary, but you can expect it to be more often than changing ATF. Most manual vehicles can go for 30,000 to 60,000 miles before needing a transmission fluid flush, but frequent and heavy-duty use can bump that number down to every 15,000 miles.

However, just because your vehicle uses a manual transmission, doesn’t mean it automatically uses MTF. Manual vehicles can also use ATF as long as the original equipment manufacturer (OEM) recommends it.

Other Factors To Consider

What’s your vehicle’s make and model? How often do you drive? Do you carry heavy cargo in your trunk? Your answers to these questions can all affect how often you need to change your transmission fluid.

If you own a big car, drive often, and tow heavy loads along with you every day, then you’re more likely to wear out your transmission fluid faster. Driving in busy stop-and-go traffic can also stress your transmission.

If you drive your vehicle hard, trying to hurry to the next light in the hopes of reaching your destination faster, you should probably service your transmission sooner.

When Should You Check Your Transmission Fluid?

These days, checking your transmission fluid isn’t so simple. Most vehicles have done away with dipsticks and instead require the vehicle to be lifted up while pulling plugs with the vehicle still running. It can certainly be a complicated process, but it’s an important maintenance task that you can’t just ignore.

Checking transmission fluid is not so simple these days. Most vehicle have done a way with dipsticks, requiring the vehicle to be lifted up while pulling plugs while the vehicle is still running. Adding fluid requires pushing it up a small tube through the pan.

Anthony Harlin, ASE Certified Master Automobile Technician

In an ideal world, you’ll never have to change your transmission fluid earlier than the recommended change interval. In reality, however, your transmission fluid can overheat and break down, causing several issues for you and your vehicle.

Difficulty Shifting Gears

Shifting gears should always be easy and smooth, but if your manual vehicle’s gear stick starts feeling a little stiff in your hand, then a transmission fluid flush might be in order. Dirty transmission fluid won’t be able to efficiently power your transmission, causing it to change gears too late or even fail to change gears completely.

Slipping Gears

Is your vehicle suddenly slipping out of gear? If the answer’s yes, then insufficient transmission fluid is the likely culprit. If your transmission doesn’t have enough fluid, it won’t have enough power to keep your gears locked, causing them to suddenly switch even if you didn’t mean to.

Grinding Noises

Unusual noises from your vehicle are never welcome, especially if they sound like grinding noises coming from your transmission.

Transmission fluid prevents different parts of your gearbox from grinding against each other, but if it’s running low or too dirty, then these parts will start scraping against each other while making unpleasant grinding noises.

Overheating Engine

Insufficient transmission fluid isn’t just a problem for your transmission–it’s bad news for your engine too. Without enough fluid, your transmission system will most likely create excess heat that can travel all the way to your engine and cause permanent and expensive damage.

Most automatic vehicles have external coolers for the transmission fluid, which is cooled by the coolant. If the coolant gets too hot, then the transmission fluid can also turn hot and cause the transmission to overheat.

Most manufacturers recommend an ATF change every 60,000 to 100,000 miles, while most manual vehicles can go for 30,000 to 60,000 miles before needing a transmission fluid flush.

How To Check Transmission Fluid

Before everything else, you’ll have to park somewhere level and safe. Once you’re in the clear, go ahead and turn on your engine, but don’t pop open the reservoir just yet. A warm engine will give you a more accurate reading, so leave your engine running for a few minutes until it warms up.

Next, locate your vehicle’s transmission fluid dipstick. Be careful not to confuse this with your vehicle’s oil dipstick, which is an entirely different thing. Once you find it, take a clean rag and use it to wipe your transmission fluid dipstick clean.

Insert the clean dipstick back, and then pull it out again. You can now check the indicator for a reading of your transmission fluid levels.

Keep in mind that this process isn’t the same for every vehicle. Some vehicles have to be in neutral gear, while some need to be in park. Meanwhile, some Honda vehicles require you to turn off the engine.

If you want to do it yourself, then your best bet is to read the service manual on exactly how the manufacturer recommends checking your transmission fluid.

How Much Transmission Fluid Do You Need?

It all depends on the type of vehicle you own. What’s your vehicle’s make and model? What’s its size? These are all questions you’ll have to ask yourself first before you can figure out how much transmission fluid your vehicle needs.

Take a small vehicle, for example. It’ll only need around 8 to 9 quarts of transmission fluid to speed down the road, whereas a heavy-duty truck will most likely require around 20 quarts for its gearbox to work properly.

Getting New Transmission Fluid for Your Vehicle

Unless you want to risk damaging your transmission, you should never put off changing your transmission fluid. Low transmission fluid can overheat, causing gunk to build up and damage your gearbox. Save yourself from an expensive repair bill by changing your transmission fluid as soon as you notice any issues. Thankfully, buying new transmission fluid is fast and easy with CarParts.com.

CarParts.com offers a wide selection of manual and automatic transmission fluid, all sourced from the most trusted manufacturers in the industry. You can easily browse through our catalog with the help of our vehicle selector and search filters. If you’re itching to get back on the road, don’t worry because CarParts.com also guarantees fast shipping. Thanks to our strategically located warehouses, you can expect your new transmission fluid to arrive in as fast as two business days. Just be sure to order by 12 PM ET.

Don’t wait until your entire transmission system starts malfunctioning before changing your transmission fluid. Check out our catalog of high-quality manual and automatic transmission fluid at CarParts.com and order yours today!

About The Authors
Reviewed By Anthony Harlin, ASE Certified Master Automobile Technician

Technical Reviewer at CarParts.com

Tony Harlin is a Master Gas and Diesel Diagnostic Technician with over 18 years of experience. He works full-time at a large independent automotive shop as a driveability and repair technician working on all types of vehicles with a focus on diesels. ASE certifications include A1-A9, L1 and L2, as well as X1.

Written By CarParts.com Research Team

Automotive and Tech Writers

The CarParts.com Research Team is composed of experienced automotive and tech writers working with (ASE)-certified automobile technicians and automotive journalists to bring up-to-date, helpful information to car owners in the US. Guided by CarParts.com's thorough editorial process, our team strives to produce guides and resources DIYers and casual car owners can trust.

Any information provided on this Website is for informational purposes only and is not intended to replace consultation with a professional mechanic. The accuracy and timeliness of the information may change from the time of publication.

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CarParts.com Research Team and Anthony Harlin, ASE Certified Master Automobile Technician