How to Check and Add Automatic Transmission Fluid (Atf)

Check and Add Fluid as Needed

Keeping your automatic transmission healthy is pretty easy and uncomplicated. Just as you put motor oil in your engine, you also put automatic transmission fluid (ATF) in your transmission. There is a dipstick to check the ATF that is separate from the dipstick you use to check your oil. Open your hood and generally look toward the back of the engine for a dip stick. It might be located down lower in the back so you may have to look down into the cavity to locate it. It might say ATF on the top of the dipstick. You can also look in your car manual for a diagram.

With your car running, pull out the dipstick, wipe it off and re-insert it to check the level. Make sure you push it all the way in. When you pull it out the second time you should be able to look at the end and see two marks indicating high and low. If it is low then you will need to add fluid. Your transmission fluid should be red not amber. If it is amber or brownish color you are probably looking at your engine oil and not your transmission fluid. Check your manual for the type of fluid recommended for your particular car.

WARNING: More is not better – do not overfill your ATF.

Transmission fluid is added directly into the dipstick tube so you will need a special transmission fluid funnel with a long spout. Don’t overfill. Check the level with the car running.

You can also ask to have the ATF checked when you take your car in to have the oil changed. The service center may already do this but it is a good idea to ask.

Transmission Fluid Leaks

You will know your transmission fluid is leaking if you see drips of red oily fluid on your driveway. If you suspect you have leaks you can place several pieces of butcher paper under your car and check it for stains of fluids. Remember transmission fluid is red and engine oil is amber or brown.

Get Your Transmission Fluid Changed Regularly

Your car manual will tell you when to change the transmission fluid. On many newer cars the manual may say that the transmission fluid does not need to be replaced. However, there is debate on this topic among mechanics and transmission shops that claim you should change your ATF anywhere between 30,000 miles for older cars and 100,000 for newer cars. You will also need to have the filter changed as part of your regular maintenance. Your driving habits will also dictate how soon you will have to change your ATF. Pulling trailers and mountain driving are much harder on your transmission. If you are in this category you may want to have it changed it at 15,000 miles.

See Basic Car Maintenance: Motor Oil for information regarding oil changes and adding motor oil.

See Basic Car Maintenance: Antifreeze and Coolant regarding checking and adding Antifreeze/Coolant.