The transmission fluid is one of the more commonly forgotten fluids in your vehicle. But just as with engine oil, the transmission fluid needs to be kept fresh. You don't need to change the fluid every 3,000 miles as you do oil, but neglecting the fluid can cause transmission failure. Transmission fluid not only lubricates, but it is also cleans the transmission and keeps it cool. Flushing a transmission is a fairly easy task, as long as you have the right tools and equipment.
Jack up the front of the vehicle. Position jack stands under the support structure of the vehicle. Lower the vehicle onto the jack stands. Remove the jack.
Locate the two metal transmission lines that run into the driver's side of the radiator. One line will be at the top, the other at the bottom. If they are going the wrong way, disconnect the lines and switch them.
Remove the lines using a line wrench. Find the proper adapter on the transmission flush machine that matches the lines. Attach the adapter to each line using a line wrench.
Plug the adapters into the transmission flush machine. Start the engine. Verify that the fluid is flowing in the right direction by checking the flow window on the top of the machine. Stop the engine.
Fill the machine with the amount and type of transmission fluid specified in the repair manual for your particular vehicle.
Plug in the machine and restart the engine. Press the "Start" button on the machine, which will continue to operate until you hear a beep. This indicates that the flush has been completed.
Remove the lines from the machine using the line wrench. Reinstall them into the radiator using the same line wrench.
Jack up the vehicle and remove the jack stands. Lower the vehicle to the ground.
Start the engine and check the transmission fluid level, following the repair manual. Fill it as needed.
Test drive the vehicle. Pay close attention to the shifting pattern and any roughness.
