It can’t really fail. Other than the car falling off it its pretty much fool proof. The clank you hear is a solid piece of bar-stock that hops over solid 2 inch thick “stops”. That bar and blocks prevent the lift from lowering even if the other components fail.
The metal it’s made out of is about three times the thickness of the frame rails on the sol and its rated to lift 3 tons. My car weighs less than one ton right now. :number1