Transmission fluid capacities far exceed the capacity of the transmission drain pan. Fluid is held in the various components of the transmission, including the torque converter, when the transmission is not in use. To change the fluid in the torque converter, you must rotate the fluid in the transmission while the transmission pump is engaged. To ensure fluid is replaced as it is expelled while the gearing of the transmission is engaged, this maintenance requires the assistance of at least one additional person.
Consult the owner's manual for exact transmission fluid capacity. Purchase or acquire the required amount of fluid necessary to replace the full capacity plus two additional quarts. The extra quarts will be needed to ensure full fluid replacement.
Place the bucket or container under the transmission cooling line at the front of the vehicle. The transmission cooling line will be near or at the edge of the radiator. The container should be large enough to hold the transmission fluid which will be replaced. Typically oil pans used to service engine oil are large enough to hold the full capacity of fluid.
Engage the vehicle's parking brake. Place wheel chocks around one wheel to prevent the vehicle from accidentally moving during maintenance.
Remove the transmission cooling line from the radiator. Unbolt or unscrew the retaining ring on the transmission line and pull the hose free from the radiator. Place the line into the collection bucket, or have an assistant hold and aim the line as fluid is expelled.
Remove the dipstick from the automatic transmission fluid check tube.
Start the engine. Place the transmission into the "Neutral" gear. Ensure the transmission fluid being expelled from the cooling line is being caught in the bucket.
Pour transmission fluid into the dipstick tube -- a funnel may be required -- the transmission fluid at approximately the same rate the fluid is being expelled from the cooling line. Pour the new fluid into a funnel directed into the transmission dip-stick tube.
Wait until approximately three quarters of the fluid capacity of the transmission is expelled. Press and hold the brake pedal. Move the transmission through all the gears for approximately 2 seconds in each gear. Move the transmission back through the gears to "Neutral."
Turn off the engine when more than full capacity of transmission fluid has been expelled.
Connect the cooling line to the radiator.
Restart the engine. Check the level of fluid in the transmission and add fluid as necessary. Drive the vehicle for 3 to 5 miles, then recheck. Top off fluid as necessary.
