Norton gearbox front chain adjuster. A new Norton laydown gearbox adjuster eyebolt + nuts + nut for top gearbox mounting bolt , assembly. Suit Nortons with laydown gearbox from 1953 to approx 1968 (swing arm and featherbed models). Covers all models ES2, 19, 50, 500T, 7, 77, 88, 99, 650, Atlas. Can also be used for plunger models. Original Part Numbers: H12/314; 16997 - front chain adjuster eye bolt and nuts D12/313; 15170; - Gearbox top bolt nut