xantia hard suspension

hi all,my xantia has gone extremly hard on the rear,changed the spheres but made no difference.it goes up and down fine via the interior lever.fluid changed as well.any ideas.and the front drivers side is rock solid but passenger front is fine

The first thing that comes in to my head is definately the spheres. Especially if still hard at ride height. When you replaced the spheres did you check the Pressures stamped on them and that the valve looked the same. Also did you purchase from a reputable place or could these be already faulty, maybe reconns etc?
Do you hear excessive clicking from the accumilator sphere? (at front of engine)