Yamaha Gear 1 Assembly 6T5-45560-00-00. Overview. The Yamaha Gear 1 Assembly 6T5-45560-00-00 is a genuine original equipment manufacturer component designed to deliver smooth and efficient mechanical operation within your Yamaha system. This complete gear assembly plays a vital role in transferring motion and maintaining proper timing, ensuring consistent and reliable performance.. Engineered to Yamaha's exact specifications, this gear assembly provides a precise fit and dependable durability. I