The W11378552 is a genuine OEM washer outer tub assembly (the stationary tub that holds water and supports the inner spin basket/drum). On many platforms it’s sold as an outer tub and basket/drum assembly (contents vary by model/catalog), and it interfaces with the rear bearing/spider support system, suspension, and door boot (front-load) or tub ring components (top-load, platform dependent). Replacement is typically required after tub cracks/leaks, bearing seat damage, severe corrosion, or structural damage from repeated out-of-balance events. Symptoms: water leaking from the tub seam/body, loud roaring/rumbling from bearing damage (often paired with tub damage), excessive vibration from broken mounts, or visible cracks near ports/mounts. IMPORTANT: This is a major repair—confirm what’s included (outer tub only vs tub+drum assembly) and check whether a bearing/spider kit is required separately. CRITICAL: Unplug washer and shut off water; this job involves full disassembly and heavy lifting.