Seals to the change shaft are frequently bundled with Mercury gear housing kits much like the one we used in the video below, which also arrived with input and output seals for the lower unit, in addition to a new gasket for the change shaft housing. Tilt the motor up https://marineelectronicsinstalla96285.blogzet.com/5-simple-statements-about-yamaha-lower-unit-rebuild-explained-46370362