How to Change Fluid in an E40D Transmissionby Justin Cupler
The Ford E4OD, which stands for electronic four-speed overdrive, was Ford's first ever electronically controlled transmission. Its predecessor, the C6 transmission, used only hydraulic pressure and mechanical linkages to operate. The E4OD uses several electronic sensors throughout the vehicle, as well as hydroelectrical solenoids to shift gears. This transmission saw use in Ford full-size truck and vans, as well as SUVs through the 1990s. Part of maintaining the E4OD transmission is to change the fluid periodically. Ford states that the fluid should be changed every 60,000 miles.
Raise the front of the vehicle with a floor jack and place the jack stands under the frame rails. Lower the vehicle until its weight is only on the jack stands.
Slide the drain pan under the vehicle until it is directly under the transmission pan, the metal pan at the bottom of the transmission.
Crawl beneath the vehicle, loosen and remove all but four of the bolts -- leave one at each corner -- from the transmission pan, using a ratchet and socket. Loosen, but do not remove, the four remaining bolts, using a ratchet and socket.
Pull down on the transmission pan to free it from the base of the transmission. Fluid will begin to drain from the pan.
Remove the remaining four bolts from the pan, using a ratchet and socket, once the fluid has stopped draining. Make certain to hold the pan as you remove these bolts, as there is still fluid in the pan and it may fall, causing a large oil spill. Tilt the pan to one side once all four bolts are removed to drain the remainder of the fluid from the pan.
Scrape the pan gasket from the top of the pan, using the razor blade scraper, and use the abrasive pad to clean the top of the pan.
Spray the inside of the transmission pan with the auto parts cleaner and wipe it down with shop rags. Make certain to clean out all of the old fluid and debris from the pan.
Place a thin bead of RTV silicone around the top part of the pan, where the gasket sits, and place the gasket on the pan. Make certain to line up the holes in the gasket with those in the pan. The RTV silicone will hold the gasket in place while you reinstall the pan.
Place the pan back on the transmission and hand-tighten the 20 bolts. Tighten the bolts to 12 to 16 foot-pounds, in a crisscross pattern, using a torque wrench and socket.
Raise the vehicle off of the jack stands with a floor jack and remove the jack stands. Lower the vehicle to the ground.
Open the Ford's hood and remove the transmission dipstick from the filler tube located at the rear, passenger's side of the engine. Place a funnel in the filler tube and add approximately 6 1/2 quarts of Mercon transmission fluid.
Reinsert the dipstick and start the vehicle. Allow it to reach operating temperature, roughly halfway up the temperature gauge on the instrument panel, and shift through every gear while holding the brake pedal.
Place the transmission indicator in "Park" and check the transmission fluid level on the dipstick. It must be inside the crosshatched area on the dipstick. If the fluid is low, add Mercon fluid until it reaches the crosshatched area.
Close the vehicle's hood and shut the engine down.
Pour the fluid from the drain pan into the empty Mercon transmission fluid bottles, using a funnel as a guide. Take this old fluid to a local auto parts store for proper disposal.