The lower casing drive requires higher levels of maintenance due to the permanent (while operating) nature of its constant exposure to highly corrosive salt water and the potential for damage from flotsam and jetsam.
These Yamaha engines are world renowned for build quality and utter dependability - provided they are serviced and maintained to a reasonable standard.
More or less all the components likely to be required are available here at CMS, allowing the remarkable engines this component suits to go on giving long years of great service.
More lower casing drive components you may wish to consider:
Add as many items as you wish to the same shopping cart, new fasteners 9017118M04914904003092990182009010510M00 for example, and still only pay the same single fixed price shipping cost.
This component may have other applications within the Yamaha model range marine and motorcycle.