Add Transmission Fluid

Transmission fluid is a slick, oily substance that keeps the transmission of your car lubricated. The type of transmission fluid you need depends on the make and model of your vehicle, and whether you drive a car with an automatic or a manual transmission. Check your owner's manual and follow directions for checking fluid level and fill procedures. Some manufacturers do not have a normal dipstick for checking and filling. The below steps are for the most common transmission check and fill procedures.

Steps

Checking Your Fluid

  1. Start your car. In order to get an accurate transmission fluid reading, you will need to check it while your transmission is running and the fluid is warm. Keep your car in park, with the handbrake on, while you check the transmission fluid. Note that some vehicles are checked in the neutral position. Reference your owner's manual for the proper position of your car's shifter.
    • If you've just finished driving your car around for 30 minutes or longer, it's a good idea to let your engine idle a few minutes before you check the trans fluid.[1] This will allow the temperature of the fluid to normalize the operating condition.
    • Note that some cars may also have a "cold" reading on the transmission dipstick. Even if this is the case in your vehicle, you should still turn your engine on and get the trans fluid heated up in order to get an accurate reading.
  2. Without actually driving the car, depress the brake and run the transmission through all the gears, including Reverse and Overdrive. If you check the trans fluid cold — i.e. not having driven anywhere and not having run through all the transmission gears — inspection of the transmission dipstick will give you an inaccurate reading. It will appear as if you have far too much transmission fluid in your car. To avoid this, cycle through all the gears in your car to help circulate the transmission fluid evenly.
  3. With your car parked on an even surface, open the hood and identify your transmission dipstick. Remember to set the parking brake, especially if you're leaving the car in neutral. On some cars, it is easy to mistake the transmission dipstick for the crankcase oil dipstick, so make sure you are clear on the location of your transmission.
    • Look towards the back of the engine, near the firewall. This is where the transmission is located on most cars with rear-wheel drive.[2]
    • On cars with front-wheel drive, the transmission dipstick is usually located in the front of the engine, connected to the transaxle. This isn't universally true, however, so you should look in your owner's manual or for labels around and on the dipstick to see which one it is.[2]
  4. Pull the dipstick out and wipe it with a rag. This will help give you an accurate reading.
  5. Stick the dipstick back into the transmission fluid and lift it out again for your reading. You should now be able to see what level your transmission fluid reaches. Remember to read the "hot" level on the transmission dipstick.

Adding the Fluid

  1. Keep your car's engine idle with the transmission in park and the parking brake activated. Your car's engine should be running when you add fluid to the transmission, but you want to have the transmission in park and the handbrake activated for safety reasons.
  2. Check the owner's manual for instructions on adding the correct transmission fluid for your vehicle. This will tell you what type of transmission fluid to use, and whether there are special instructions for adding fluid.
    • The transmission dipstick itself might also tell you what kind of transmission fluid the transmission takes. Note that there are several different kinds, each with specifications that make it favorable for that engine's transmission.
    • Also look for instructions on how frequently to change your transmission fluid. While you can add fluid when it gets low, many car manufacturers recommend a transmission fluid change every {{safesubst:#invoke:convert|convert}}, depending on your car.
  3. Place a funnel in the dipstick hole of the transmission. It will need to be a fairly long funnel to ensure you do not overfill.
  4. Pour the correct fluid slowly into the transmission. Add a little at a time so you do not overfill. How much transmission fluid do you add to your vehicle? It depends on what you're doing:
    • Are you topping off fluid level? If you notice the transmission fluid is a little low on the dipstick, start with a half a quart to a quart of transmission fluid. Recheck the level and add 1/4 quart at a time till the level is up to the full or max mark.
    • Are you doing a transmission service, where you drop the pan and replace the filter? This kind of service regularly needs 4 to 5 quarts of transmission fluid in order to replace what was lost in the pan.
    • Are you replacing the entire transmission fluid? It could take anywhere from 9 to 13 quarts of transmission fluid to adequately replace the entire transmission fluid.
  5. With your vehicle still idling, depress the brake and run the transmission through its gears. This will help circulate all of the transmission fluid and make sure you're getting the correct reading.
  6. Check the fluid level once more. You may not need to add more transmission fluid, but if you do, you'll want to add the fluid gradually rather than pouring all at once. Again, most vehicles will not need more than 1 pint (0.5 liter).
  7. Return the dipstick to the transmission hole and make sure it is on tight. You will need to turn it until it locks or press down a latch on the top of the dipstick to lock it into place.

Tips

  • Ask your mechanic to check your transmission fluid any time you have your car serviced. If you are not comfortable adding transmission fluid on your own, ask your mechanic to do it.
  • Some transmissions do not have a dipstick to check and fill the transmission. These are what the manufactures call tamper proof. The manufactures only want the fluid checked and filled during major service intervals. Some manufactures do not want fluid changed at all. Follow your manufacturer's recommendations for checking and servicing of your transmission.
  • Every 30,000 thousand miles you should flush your transmission fluid and put new fluid in because the fluid can get rough and cause problems to your transmission.

Warnings

  • Consider having your mechanic look at your transmission if you notice yourself adding fluid regularly. If you lose transmission fluid, you may have a leak.
  • Make sure you do not pour the wrong type of fluid into your transmission. Doing so can damage your vehicle, and the repairs you need to make will likely not be covered by your warranty.
  • If you do not flush your transmission and let it go a 100,000 miles you risk your transmission wearing out more, proper flushing of the transmission every 30,000 miles will make your transmission last a long time.

Things You'll Need

  • Rag
  • Transmission fluid
  • Owner's manual
  • Funnel

Related Articles

Sources and Citations