The CORTECO Crankshaft Seal, part number 12010959B, is engineered specifically for manual transmission applications. Its primary function is to create a reliable seal around the crankshaft, preventing lubricating oil from escaping the transmission housing. A properly functioning crankshaft seal is crucial for maintaining the correct oil level within the transmission, which is essential for the longevity and smooth operation of its components. This seal helps to protect the transmission from contamination by external elements, further contributing to its durability. Crafted with quality materials, this CORTECO seal is built to withstand the demanding conditions of a vehicle's drivetrain. It offers a precise fit, ensuring straightforward installation and dependable performance over time. Replacing a worn or damaged seal promptly can prevent significant damage to the transmission and surrounding parts.