plastic part in the trans pan???

Hey all, my friends little brother just picked up a junkyard AOD for his 5.0. He was changing the trans filter when he looked down and saw a piece of white plastic that came out of the pan. It's about 2" long, kinda looks like a plunger with a rounded head and a rubber gasket around it. We looked and none of us could see anywhere this thing would go. This piece fits perfectly in the dipstick hole, so could this have been a plug used on the factory line or is this something else? Thanks for any help.

This piece fits perfectly in the dipstick hole, so could this have been a plug used on the factory line or is this something else? Thanks for any help.

That's exactly what it is.

Thanks GTStang, just wanted to be sure it wasn't anything important.

Relax, I went through the same thing, even went to my local Ford dealer. Turns out it's a plug that is placed into the filler tube hole after building to keep out dust and dirt. When they build the car and put the filler tube in they just push it in and let it rattle around in the oil pan. Shows you that the AOD was never serviced.