Crankshaft main bearings quietly carry the entire load of an engine, keeping the crankshaft stable even under extreme pressure. These precision-built bearings reduce friction, allow smooth rotation, and help maintain perfect alignment as the engine fires thousands of times per minute. When main bearings wear out, drivers often notice knocking sounds, low oil pressure, or uneven performance. High-quality materials like tri-metal or aluminum alloys help these bearings withstand heat and stress. Regular oil changes also play a major role in extending their life. Without healthy crankshaft main bearings, even the most powerful engine can lose efficiency or fail. This tiny component truly supports the heart of every vehicle.