Crawled under the truck (04 FX4 SCREW) the morning to change my oil and noticed that the access hole cover on transmission case is missing exposing the flywheel. Is this a problem? Why would it be missing? See photo.

 

Plastic plug came out..you should be able to order one.

 

My pick-and-pull/ wrecking yard charged me 1 dollar for it, it's found on f150's all the way back to the early 90's so they are very common to find, all you need is a screw driver to pop it out. Best of luck