Ditto, I would change all four also to keep the ride even. I fitted ProComp which have worked well for me. They give a softer more comfortable ride. When heavily loaded you can feel it which I couldn't with the previous set. (Don't know what they were as they were well worn) The ProComp have also survived a trip across Morocco fully loaded and are still good to go again. Some people on here knock them but I can only speak as I find. One of the vehicles in our group that went to Morocco had new Terrafirma shocks, one broke.