A dry steering box can do that.Make sure there is some lube in it,plain grease squeezes out and will let it run dry.It needs something like gear oil to lube it.Also,make sure the tie rods and the steering damper are not rubbing on the frame head anywhere.A frozen damper will do it too,but from what I have seen over the years when the damper goes it dries out and just gets loose.
