A turbo compound transmission, such as in a heavy duty or medium duty diesel engine, includes a turbo compound turbine to be driven by exhaust gases from an internal combustion engine, and a coupling including a first rotor including a mechanical input drive adapted to be driven by the turbine, and a second rotor including a mechanical output drive. A brake is arranged to brake and limit the rotation of the turbine. The coupling is arranged to decouple when braking with the brake, subjecting the coupling to a torque above a predetermined torque limit. A method for controlling a turbo compound transmission is also disclosed.