When your Super Duty’s steering feels weak under big tires or heavy loads, PSC’s BIG BORE XD Cylinder Assist Kit is the fix. This complete system replaces the factory setup with heavy-duty components designed for serious steering performance. Each kit includes our XD Cylinder Assist Steering Gear , PSC Cylinder Assist axle mount kit, and PSC 715 high-performance fluid —plus all hoses, brackets, and hardware for a clean, bolt-on install. No guesswork, no piecing parts together. Just everything you need to steer with confidence.