Yamaha - Lower Case Packing Lower Unit Seal Component 6L2-45315-A0-00. Overview. Seals inside the lower unit don't get much attention until something starts leaking, but they're critical to keeping everything protected. When this packing wears out, you can end up with water getting in or gear oil leaking out-both bad news for the gears inside. I've seen small seal failures turn into major repairs just from being ignored too long. Replacing it during service keeps the lower unit sealed tight and running the way it should.. Key Features. Reliable Sealing Function - Helps keep gear oil contained and prevents water intrusion.. Protects Internal Components - Maintains proper lubrication for gears and bearings.. Corrosion-Resistant Material - Built to withstand exposure to harsh marine environments.. Factory-Spec Fitment - Designed to match Yamaha tolerances for proper sealing and installation.. Ideal for Routine Service - Commonly replaced during lower unit maintenance or rebuilds.. Engine