03 Steering box help

[dayusex]

So im trying to locate the steering box, where the nut and bolt is where I can "tighten" up my steering since I just replaced all ball joints and the steering box and it is getting sloppy again.

I assume its the box where the pitman arm was attached but could nto find the nut and bolt they were talking about. Do I have to remove the air filter to get to it?

Pics would be great thanks!