R Geiger is right. I will add that wear on the pinion bearing can increase backlash, too. If you can move the steering wheel up and down, the pinion bearings are worn.
Now the bad news: normally, loose steering in a 9N/2N is caused by wear of the pinion and sector gears. Be prepared to replace all the gears, as they all seem to wear out pretty evenly. My pinion gear was almost completely gone, but the tractor still steered, although there was about a half turn of backlash!