Sierra 18-2407 Gear Set for Mercruiser MR/Alpha/Gen 2 Lower Gear HousingsSierra replacement gear set for MR/Alpha One/Gen II engines.Set Contains: (1) 18-1117 Pinion Bearing; (1) 18-1143 Tapered Roller Bearing; (1) 18-1155 Ball Bearing; (1) 18-1158 Carrier Bearing; (1) 18-2285 Shim Set; (1) 18-2294 Shim Kit; (1) 18-2343 Pinion Nut Washer; (1) 18-3719 Pinion Nut; (1) 18-2206-1 Gear Set; Interchangeable with: GLM; 11312; Mercruiser Stern Drive; 43-878087A4; 43-42933A3; 43-42933A2; 43-17064A3; Mercury Marine; 43-828072A2;