Steering Advice

I have a 2001 R/R and i have a slight problem with the steering @ around 60-80 mph the centre of the steering feels light as if there is play in the steering, is this normal ? If tis is not normal what do you think need checking steering box ( adjusting), ball joints, steering damper. There is a slight vibration but nothing major just think it is whel balance.
Cheers Dave

steering boxes can be adjusted, you will feel play on lock but shouldn't when pointing straight ahead, cant think why it should happen at certain speeds though?