Patent ID: 8267732

Claim:
A marine drive comprising a lower gearcase with a vertical drive shaft driving a horizontal propeller shaft in a torpedo housing having a front and rear and having a propeller mounted on said propeller shaft at the rear of said torpedo housing, said torpedo housing having a top and a bottom and an internal cavity holding lubricant, said lubricant having an upper surface at a given level in said lower gearcase, a vent plug having a discharge condition to discharge lubricant from said internal cavity such that said given level of said lubricant in said lower gearcase is substantially at the top of said torpedo housing, wherein said torpedo housing houses at least one drive gear therein driven by said drive shaft, said lower gearcase has a drive shaft housing portion extending upwardly from the top of said torpedo housing, wherein said discharge of lubricant enabled by said vent plug lowers the level of lubricant in said lower gearcase to be substantially at the top of said torpedo housing and below said drive shaft housing portion, to reduce excessive lubricant churning created by said drive gear churning through lubricant, and concordantly reduce heat, power loss and foaming of lubricant otherwise caused thereby.