How do i change the transmission fluid for a 1999 ford 250 econoline

First remove the transmission oil pan remove the bolts that hold it on, next remove the filter and remove the gasket. Use 3M weather stripping glue to glue new gasket to the pan, (N0t the Transmission) remove the screw holding the filter on and remove it, if it’s plugged you will get fluid on you so have a piece of cardboard under you to catch as much as you can. Replace filter be sure to install new o ring and put a slight amount of fluid on the o ring to get it to slide back in place and seal replace bolt holding the screen back on. Reinstall pan bolts tightening from left to right just get the bolts snug then tork them from left to right and front to rear working from the center going out to the ends. Once it's tight add 5 quarts of transmission fluid to the filler tube, now disconnect the transmission cooler line from the radiator and put a big pan under the connections, start the car and et it run for a couple of minutes shut off and check oil level add more fluid and do the same, if the fluid won't come out wile running put brake on and put in gear, it will pump out a quart every thirty seconds so run for anther minute and a half, once the fluid is read and the transmission is low enough to add more then retook line to radiator, add one quart of Lucas trans mission oil conditioner then top off with fluid to the full make with car running and level in park. Top off to full make. You should notice a big difference if smooth shifting and better performance and fuel mileage. Use Dexron III transmission fluid. Please rate, as this is all I ask for free information. Buying a book would cost you $24.00 so when you rate that’s your thanks to me for my time. If you need more assistance post here and I will help you more if I can.

Some of the newer vehicles have a bolt in the middle of the transmission pan to remove the fluid. If yours don't, you will want to buy a gasket before you change the fluid as you will need to take the pan off to change the fluid. You will probably want to change the filter while you are there also. A word of advice. ---- don't over tighten the bolts around the pan when you put it back on or you will split the gasket and / or have leaks.

hope this helps