The seal is an over the counter item (still!) at Ford. It's around $3. You can get it from Napa, TransStar, and several other places. It turns out it is the same as a C6 and thus has been in been in the parts supply for so long.
To replace? Caution. On an FMX you must *carefully* remove the main pickup tube out of the valve body. Use patience. Very gentle touch with a screwdriver. If you force the tube you will kink it. Once you pry the pickup tube out of the main body watch for the servo tubes (thin tubes). Unscrew the main valve body attach bolts (only some are used to attach to the case). Gently rock the vb off of the servo tubes and you will then be able to gain access to the shift lever.
Be sure to refer to your shop manual should you get stuck.
I did one of these with the trans in the car. The only hard part was getting the spring loaded 'stop" and the rod together. If you like trans fluid down your arm give it a try.
Next time I'll flip the car over!! Did I say next time! "Never Again"
I just put in a AOD!!
Your pretty much right Bill! I'm not very good at explaining it but that spring loaded "dog" or "stop like you called it is the royle PITA when your on your back. I finally greased the hole the dog went in to help hold it and reeached up in there and disconected the link on the slotted cam and turned it all the way up, then turned it back down over the dog.
Other than that though that FMX is a good ole trans that dont give much trouble. mm