I merged onto the highway this morning, and noticed that my 2004 5.4 would not go past 2nd drive. The engine revved up higher and higher(rpm's rising), but it never went into 2nd. I pulled over, and checked all of my fluids. Everything was fine. The gear shifter changes into all gears fine as well.
I started back up, and began to drive. The same thing happened. RPM's went to almost 4k, but I was going about 25 mph.
I pulled over again to think about my next plan of action.
While sitting there, I decided to turn off the overdrive. I pressed the button, and my dash showed: "O/D Off". I started driving, and everything worked like normal. Very odd!
Has anyone encountered this problem before? It is a prelude to something major about to fail?
Details:
2004 5.4 Lariat
129K
No tune or any mods to the engine.

 

Any thoughts?

 

Bump

 

When my 04 did exactly as you described, I was out a transmission. Something about the od belt coming apart.

 

I had an issue like this with a Mazda B-Series (re-badged Ford Ranger) a few years back.

It turned out that a speed sensor in the transmission went out and the tranny wouldn't shift unless I pegged it or turned off OD. Was like $150 or $200 bucks out the door.

 

Thanks for replies guys!
Another variable has been thrown into the mix. A couple days after my OD problem started, I began getting the 'check charging system' message. That started on Friday. This morning I took it to an advance discount auto to have the electrical system tested. Turns out my alternator is not charging at all. The guys at the store told me that the only reason why my truck is even starting is because of the Optima Batt I have installed. I guess that batt is maintaining its own charge better than a standard batt would. But even it has limits. It's sitting at about 11.9 now and will steadily drop until I get the Alt replaced.
I wonder if my O/D problem is related to the Alternator? Or if the Alt is just ANOTHER problem on my plate.