Hello - for those of you who still have a 2.3 Duratec engine or a similar engine, maybe this will solve or resolve the problem on pulleys bolt from breaking. I do not have a Focus or a Fusion but own a 2008 2.3l Escape. I believe the culprit is the Power Steering. Upon START UP of engine, all the components that are connected to the serpentine belt (such A/C, power steering, water pump, alternator, pulleys, etc) brings STRESS to the pulley's bolt. This usually happen upon Start Up of the engine after it has been turned off. To solve this problem, NEVER start your engine with your HAND resting on the Steering Wheel. I am referring to the LEFT HAND and right RIGHT HAND is on the ignition switch So, HANDs OFF the Steering Wheel upon Start Up of your engine. Best Wishes!