Mine on a 54" Lightning has lasted from 2008. They are units originally designed for gates and the big 10' sat dishes, ball and screw actuators. Be wary of the travel at the very end of the stroke as sometimes the unit will not retract because the ball has reached the end of the screw and disengages. I have to be mindful of how low I can go with the deck and stop before entering the disengagement zone, usually below the height indicator's last position at 1" cut height. Should have been some sort of mechanical stop built in.