Parts such as the Transmission: Wash,thrust 25mm, Brg,ndl.30x35x17, Gear,m-3, Washer,thrust,30x are included in the Trx680fa 2010 (a) Australia Transmission parts fiche.
The component with the lowest price in the TRANSMISSION schematic is the Circlip,spl,23mm.
On this parts fiche the O-ring, 31.2x1.9 is the most specified component.