There is no adjustment on the steering. At the bottom of the steering shaft is a gear and that engages with a quadrant attached to the steering drag link. These gears wear and come out of engagement hence loosing the steering. The gear and quadrant must be replaced as a pair and it is not difficult just awkward. Ensure the front tyres are kept hard and apply plenty of grease to the gear/quadrant assembly.
Good luck.
Marstafitta
June 2009