2006 Sport 61000 miles. Rear shocks were replaced at 52000 miles due to leaks. Replaced with Monroe replacement shocks. A week ago i noticed a rattle coming from behind the rear left panel. I removed the cup holder insert and noticed that the screw securing the left rear shock was quite loose and the noise was coming from the vibration. I put a socket on the screw thinking it may have been loose but it never gets tighter. I checked the shock on the opposite side and it was unable to budge with a socket on it. Is that shock broken, or is there a special way to tighten a loose screw, actually does the loose screw indicate another problem. Thanks in advance.