1994 Ford Explorer Eddie Bauer Transmission

Recently I've been having transmission trouble with a 1994 Ford Explorer Eddie Bauer Edition (4.0L V6, 4x4). The problem was that the car would suddenly downshift going at high speeds. Now, the mechanic says that there are only 4 gears, and that it's shifting into all gears, but I would swear on my life there are 5.

I know there are 5 because at 75mph I used to be at 2500rpm, but now it's shot up to over 3000rpm, and going slower speed. It's missing a gear, but the mechanic thinks I'm an idiot. Does the 1994 Eddie Bauer edition come with an optional 5-speed automatic?