Power!! That's what you need. My rear ones were fucking stiff. Soaked it with WD-40, cleaned the muck with a tooth brush. Had to spin it opposite way, then it span the way i wanted it so it can go lower. Did you try spinning it the opposite way? All it is, is shit stuck in the threads. You need to clean it as much as you can, let the WD-40 do its job where you can't reach. then try again.