Case IH 51674508 Viscous Fan Drive Assembly

The 51674508 viscous fan drive is an electronically controlled cooling component designed for Case IH Magnum series row-crop tractors. It dynamically adjusts fan speed in response to electronic sensors and control modules monitoring real-time engine temperature, coolant temperature, and engine load. This variable-speed operation reduces parasitic power loss, lowers noise levels, and improves fuel efficiency compared to fixed-drive fans. The unit replaces OEM part numbers 48185793, 84278715, 84416324, 84397784, 51433189, 51433189R, 84559831, and 84416327. It is also compatible with New Holland Agriculture tractors using the same part number. Key engineering parameters include a rated input speed of 2750 RPM, a maximum permissible input speed of 3000 RPM, an outer diameter of 318 mm, and an overall length of 146.3 mm. The assembly weighs approximately 8.0 kg. The drive utilizes a viscous shear mechanism actuated by an electronic solenoid valve, enabling precise thermal management under heavy draft and PTO load conditions typical of Magnum 235 through Magnum 400 models.