Classic/Antique Car Repair: adjust steering box 79 lincoln, center shaft, lincoln mark

Question
have 1979 Lincoln mark v  there is a nut on top of steering box, how do you adjust it.    there is a little play in steering wheel.

Answer
The nut is a retainer or stop and the center shaft with allen wrench reset or flat slot is the adjustment. Loosen the nut holding the center still. Then turn the center (clockwise) in 1/2 turn at a time, check the 'slop' in the steering each time. Best done with motor off. Re-tighten nut