Yamaha - Lower Case Packing Lower Unit Seal Component 6L5-45315-A0-00. Overview. This is one of those small sealing parts that does a big job inside the lower unit. When packing starts to wear out, you'll usually see it in the form of gear oil leaks or water getting where it shouldn't be. It's not something you want to ignore, because once contamination starts, it can lead to bigger issues fast. Replacing it during service keeps everything sealed up tight and running the way it should.. Key Features. Reliable Sealing Function - Helps maintain proper sealing between lower unit components to prevent leaks.. Protects Internal Components - Keeps water out and gear oil in for consistent lubrication.. Corrosion-Resistant Material - Designed to hold up in harsh marine environments.. Factory-Spec Fitment - Matches Yamaha tolerances for proper sealing and installation.. Essential Service Component - Ideal for lower unit rebuilds or routine maintenance.. Engine & Boat Compatibility. Designed for