My 1994 F-150 has been pulling hard to the right. Took to Ford dealer and they aligned it. Picked up truck from dealer and it was still pulling to the right Talked to service writer who claimed I need a new steering box.
Does this make any sense?

 

My truck has play in the gear box and it drifts left and right depending on the grade of the road I'm on and when jacked up, I can turn the wheel left or right and have a knock when the gears align inside the box indicating severe wear. Pulling to one direction........I wouldn't look to the gear box for a left or right pull first. I guess it's possible, but it doesn't sound right to me. Jack it up with both front wheels off of the ground and see if you have any play in the wheel before the wheels turn or if you have bump or knocks when you wiggle the steering wheel and have someone help you find those bumps or knocks. My springs were sagging severely and new springs corrected 90% of my drifting issue as the wheel were leaned in at the top from the weak springs.

Edit - Don't put any trust in a dealer mechanic. I had my front end aligned 6 months ago with no mention of the bad springs or radius arm bushings or anything else. My personal mechanic found all of my issues. My Chevy Dealer will not even look at our 2002 or 2003 Silverado and GMC. We have to take them to a Cadillac Dealer as the Chevrolet Dealership will not work on anything older than 2005 models. I'm done with dealers.