The steering wheel is harder to turn when the wheels are in the straight position, but free up noticably when the wheel is turned about 45 degrees in either direction. Do I need to back off the steering box adjustment screw a tiny bit, or do i need to lube my steering column..?

It's a pissy annoyance, it's just THAT little bit more uncomfortable correcting the car on a highway all the time when the steerings hard..

what tyres and is the pressure up a bit
then is the box or a tie-rod end worn keep pressure up may help

if you back off the steering box adjustment it will free it up but,,you will have a little bit more play as you turn the wheel

The tyre pressures are high enough - about 32psi..

I was thinking that the adjusting screw may be 'on' too tight, so backingit off an 1/8th of a turn might help.. I'll try that when I get a chance.. I hate freeplay!