Yesterday I replaced the Water Pump and Fan Clutch on my '05 4.7. At idle, everything sounds fine. When driving it's a different story. When the engine hits >2500 RPMs, sounds like I'm in the cockpit of a C-130. There is loss of power, and fan speed seems to be dependent on engine RPM, regardless of the gear or temperature. New Fan Clutch is stiff while cold. What steps do I need to take to correct this issue?