A dual exhaust valve rocker arm assembly operable in a combustion engine mode and an engine braking mode, the dual exhaust valve rocker arm assembly selectively opening first and second exhaust valves (50, 52) and comprising: a rocker shaft; an exhaust valve rocker arm assembly having an exhaust rocker arm that receives the rocker shaft and is configured to rotate around the rocker shaft, the exhaust rocker arm further defining a bore having an inner diameter; an engine brake rocker arm assembly having an engine brake rocker arm; and an engine brake capsule slidably received along the inner diameter of the bore of the exhaust valve rocker arm, wherein the engine brake capsule includes an engine brake capsule piston and an engine brake capsule body, wherein a pressurized oil chamber is defined between the engine brake capsule piston and the engine brake capsule body, wherein the engine brake rocker arm is configured to act on the engine brake capsule piston which acts on the engine brake capsule body which ultimately acts on one of the first and second exhaust valves (50, 52), and wherein the engine brake capsule is selectively translatable upon urging by the engine brake rocker arm-, the engine brake capsule, in turn, urging one of the first and second exhaust valves (50, 52) open during engine braking mode; wherein the dual exhaust valve rocker arm assembly further comprises: an oil control valve that provides oil flow for actuation of the engine brake capsule from a pressurized oil supply, characterized in that: the dual exhaust valve rocker arm assembly comprises: a lock ball assembly including a ball lock and a ball lock spring; wherein the ball lock spring of the lock ball assembly is configured to urge the ball lock into a groove defined on the engine brake capsule body to provide retention of the engine brake capsule body in the combustion mode; wherein, when the engine is in the combustion mode, the oil control valve is closed and the engine brake capsule body is completely retracted having no influence on the first and second exhaust valves (50, 52) motion and is retained by the lock ball assembly. a rocker shaft; an exhaust valve rocker arm assembly having an exhaust rocker arm that receives the rocker shaft and is configured to rotate around the rocker shaft, the exhaust rocker arm further defining a bore having an inner diameter; an engine brake rocker arm assembly having an engine brake rocker arm; and an engine brake capsule slidably received along the inner diameter of the bore of the exhaust valve rocker arm, wherein the engine brake capsule includes an engine brake capsule piston and an engine brake capsule body, wherein a pressurized oil chamber is defined between the engine brake capsule piston and the engine brake capsule body, wherein the engine brake rocker arm is configured to act on the engine brake capsule piston which acts on the engine brake capsule body which ultimately acts on one of the first and second exhaust valves (50, 52), and wherein the engine brake capsule is selectively translatable upon urging by the engine brake rocker arm-, the engine brake capsule, in turn, urging one of the first and second exhaust valves (50, 52) open during engine braking mode; wherein the dual exhaust valve rocker arm assembly further comprises: an oil control valve that provides oil flow for actuation of the engine brake capsule from a pressurized oil supply, characterized in that: the dual exhaust valve rocker arm assembly comprises: a lock ball assembly including a ball lock and a ball lock spring; wherein the ball lock spring of the lock ball assembly is configured to urge the ball lock into a groove defined on the engine brake capsule body to provide retention of the engine brake capsule body in the combustion mode; wherein, when the engine is in the combustion mode, the oil control valve is closed and the engine brake capsule body is completely retracted having no influence on the first and second exhaust valves (50, 52) motion and is retained by the lock ball assembly. the dual exhaust valve rocker arm assembly comprises: a lock ball assembly including a ball lock and a ball lock spring; wherein the ball lock spring of the lock ball assembly is configured to urge the ball lock into a groove defined on the engine brake capsule body to provide retention of the engine brake capsule body in the combustion mode; wherein, when the engine is in the combustion mode, the oil control valve is closed and the engine brake capsule body is completely retracted having no influence on the first and second exhaust valves (50, 52) motion and is retained by the lock ball assembly.