A counter knife bank assembly (10) of a chopper assembly (12) for an agricultural combine is provided that can pass obstructions without damaging the knife blades of the knife blade assembly. The counter knife bank assembly (10) includes a knife bank (24) and a lever assembly (26) connected to the knife bank (24). The knife bank (24) is moveable between a first position and a second position relative to a stationary frame (40) of the chopper assembly (12). The lever assembly (26) includes an extension member (52) having a first end connected to the knife bank (24), a biasing member (54) connected to the extension member (52), and an abutment member (56). The abutment member (56) is engaged with the biasing member (54) and is biased against a stationary support member (36) of the counter knife bank assembly (10) for articulation therewith.