Where do I insert the transmission fluid in my 2002 ford explorer sport trac?

Hello, the transmission on this vehicle, a 5R55E, has a fill plug and a drain plug only. A special threaded insert tool goes into the fill plug to fill the transmission in the vehicle. This transmission typically is not serviced during the useful life of the vehicle, as it has Mercon V transmission fluid which is deemed to be long lasting. If you have made repairs or a leak has occurred, you may need to fill the transmission via this special tool. This is not really a do-it-yourself thing, typically, so seek a local shop near you that can take care if it for you. What is making you think the transmission fluid level is the cause of your concerns? I'd say by the description of what you say is wrong, it's not likely to be the case. www.repairpal.com/repair-shops