A valve assembly for an exhaust system of a vehicle. The valve assembly includes a first housing, a second housing, a valve flap and a spring. The first housing defines an inlet, an outlet, and an exhaust gas passageway in fluid communication with the inlet and the outlet. The second housing is attached to the first housing and defines a compartment. The valve flap is rotatable between a first position restricting exhaust gas flow through the exhaust gas passageway, and a second position whereat exhaust gas flow through the exhaust gas passageway is allowed. The spring is disposed in the compartment and out of the exhaust gas passageway. The spring engages the valve flap to bias the valve flap toward the first position.