A gang assembly of a tillage implement has disc blades suspended from a support bar with a disc hanger assembly. A disc adjustment mechanism is configured to pivotably attach the disc hanger assembly for each of the plurality of disc blades to the support bar. The disc adjustment mechanism includes a pivot mount for each of the plurality of disc blades. Each pivot mount has a pivot configured to pivot the pivot mount, a first arm connected to the disc hanger assembly, and a crank arm. A shuttle is attached to the crank arms and causes each pivot mount to pivot and adjust the disc angle of the associated disc blade. The disc hanger assembly is configured to position the disc blade such that a vertical center line of the disc blade extends through the pivot point of the pivot.