put my truck up on the lift and noticed it was dripping in tranny fluid
im gueesing the rear seal of course

how much is this gonna cost me to buy? i will fix it myself so is it hard to do? (i doubt it will be hard)

i was also a half a quart low in fluid

 

If your under warranty, have Ford fix it. Mine leaked at that point when new. I thought it was the seal also. but it wasn't. The dealer replace the seal twice with no success. Then They replaced the slip joint and that took care of it. The serivce writer said they have seen some slip joints that weren't machined exactly right and didn't fit perfect. One way to tell the difference is look at the floor pan just above the tail of the tranny. If it is oily it probably is being slung of the slip joint as it turns. If it isn't then it is probably just dripping from the seal.