Fluid condition check for sure. As far as the undercarriage wash that would make me think something is binding with the steering components and spraying water under there is somewhat temporarily lubricating the sticking component with water. Grease all fittings and maybe put it up on jackstands and try the steering when suspended. You might find the "sticky" points at certain areas during the turn radius. Bent steering shock, seized or binding ball joints etc. Don't forget belt condition ???