18 tooth "S" 1275Gt Ist motion shaft for later A plus mainshaft. Used by

competitors who have to use standard gears but wish to upgrade the 14mm end

of the mainshaft to the later 18mm type with the larger bearing to give better

longevity. Fitted 1979-81 as standard on 1275GT and will work with laygears stamped DAM3168 and 22G1040.