Transmission fluid is a thick, oily substance that keeps your car's transmission system lubricated. The type of fluid you need depends on the make of your car and if it has an automatic or mechanical gearbox. Add transmission fluid by checking the fluid level, reading the car manual, and finally using a funnel to add oil to the car. Here you will learn how.
Method 1 of 2: Part One: Checking the Liquid
Step 1. Start your car
To get an accurate reading on the amount of transmission fluid in your car, you should measure it while the transmission is running and the fluid is warm. Keep your car in “Park” (“P” on automatic transmission cars) with the parking brake engaged while you check the amount of transmission fluid.
- If you've just finished driving your car for 30 minutes or more, it's a good idea to keep your engine in neutral for a few minutes before checking the fluid. This will allow the liquid temperature to normalize the operating condition.
- You should realize that your car may have a “Cold” reading on the fluid dipstick. Even if this is the case in your car, you should start your engine so that the liquid warms up a bit for a more accurate measurement.
Step 2. Without driving the car, get the transmission to work in all gears, including reverse and fifth gear
If you check the fluid while it is cold, for example without having driven anywhere and without having the transmission work in all gears, you will only have an inaccurate reading when checking the dipstick. The dipstick will show an indication that your car has too much transmission fluid. To avoid this, have the gearbox go through all gears to help the fluid circulate evenly.
Step 3. With your car parked on an even surface, open the hood and identify the transmission fluid dipstick
In some cars, it's easy to confuse the transmission fluid dipstick with the oil dipstick, so make sure you know the location of the transmission.
- Look towards the rear of the engine, close to the wall of fire. This is where the transmission is located in most rear-wheel drive cars.
- In front-drive cars, the dipstick is usually located at the front of the engine, connected to the cross shaft.
Step 4. Remove the dipstick and wipe it clean
This will help you get a more accurate reading.
Step 5. Insert the dipstick into the transmission fluid and remove it again to take the reading
Now you can see the level that the transmission fluid reaches. Remember that you should read the “hot” mark on the dipstick.
Method 2 of 2: Part Two: Adding the Liquid
Step 1. Keep your car's engine running and the transmission in “park” (“P”)
Your car's engine should be running when you add fluid to the transmission, but the transmission should be in park and the parking brake on for safety reasons. Open the hood.
Step 2. Check your car's owner's manual
This will tell you what type of transmission fluid to use and if there are any special instructions you need to follow to add it.
- The transmission dipstick can also tell you what type of fluid the engine uses. You should know that there are different types, each with specifications that make it favorable for the transmission of that particular engine.
Also, look up instructions on how often you should change your transmission fluid. Although you can add fluid when the amount is low, many car manufacturers recommend that it be changed every 50,000 to 160,000 km, depending on the car.
Step 3. Place a funnel in the hole in the transmission rod
This funnel should be long enough to make sure you don't over-fill it.
Step 4. Pour the correct fluid slowly into the transmission
Add it a few at a time so as not to overdo it with the amount. How much liquid do you need? It depends on what you are doing:
- Are you filling it up after years of neglect? If you saw that the transmission fluid was low, when measuring it with the dipstick, start with half a quarter to a quarter of transmission fluid. Keep checking and adding a quarter at a time, until the level is full.
- Are you doing transmission maintenance, where you remove the canister and change the filter? This type of maintenance regularly requires between 4 and 5 quarts of liquid to replace what was lost when the container was removed.
- Are you completely changing your transmission fluid? You may need 9 to 13 quarts of fluid to replace everything properly.
Step 5. Start the engine and make the transmission work in all gears
This helps circulate all of the liquid and makes sure you get a correct reading.
Step 6. Check the amount of liquid one more time
You may not need to add more liquid, but if so, it would be better to gradually add more liquid rather than pouring it all in at once. Again, most cars will need no more than half a liter.
Step 7. Return the rod to its hole and make sure it is tight, you will need to twist it until it locks or press a latch on the rod to lock it in place
Ask your mechanic to check your car's transmission fluid every time you do maintenance. If you don't feel comfortable adding it on your own, ask the mechanic to do it
- You should consider having your mechanic check your transmission if you find yourself adding fluid regularly. If you lose transmission fluid, there may be a leak.
- Make sure you are using the correct type of fluid for your transmission. Adding the wrong type of fluid can damage your car, and the repairs you will need to do will not be covered by the warranty.