Steering Gear?

I have a '03 F250 Diesel Superduty. It's loaded - everything except the auto back window. Powersteering is a problem - I've gone through and replaced the ball joints, tierod ends, and even the pitman arm joint as well. Everything is nice and tight from both wheels right to the sector shaft. I'm now looking at the steering gearbox and wondering if it can be adjusted on this truck? I can't really see the top of it without moving a bunch of stuff - has anyone experienced it on this truck?