I have a 2004 F-150 (automatic trans. w/118,000k)and my transmission has been going into neutral while Idrive in D at about 30-45 miles per hour. I can turn overdrive off and drive in all three speeds without a problem. All other gears are working as well. I checked the fluid and it is full and clean. I also checked the overdrive fuse and it looks fine. Is there any chance its something simple or am I going to have to remove the transmission?

 

06 E359 5.4 4R75 207,000 miles. Trany freewheeled twice and within 200 miles dead. $2,600 for a 5 year 75K mile rebuilt. No other slipping that I noticed. Fluid was due but smelled fine.
I hope it all works out and is a simple fix.

 

Most likely the snap ring for the overdrive servo broke and the piece is stuck in the valvebody. There are videos on youtube that detail how to fix it. It's not hard at all just be careful when removing and working on the valvebody. There are several check ***** inside that have to go back where they came from.