Yanmar 129403-18050 Turbocharger Assembly RHB31

The 129403-18050 is an IHI RHB31 model turbocharger designed for Yanmar industrial diesel engines. It features a wastegate actuator for boost pressure control and utilizes a water-cooled bearing housing. The compressor wheel is aluminum alloy; the turbine wheel is Inconel for high-temperature exhaust gas resistance. The CHRA (Center Housing Rotating Assembly) rotates on floating journal bearings lubricated by engine oil supply. This unit replaces Yanmar OEM part numbers 129403-18050, 129189-18010, and 129137-18010. It is interchangeable with IHI short specification codes CY26, MY61, and CY62. Cross-reference part numbers include VA110024, VA110021, VB110024, B31CAD-S0024B, 3T508, T110664, NB130015, and NB130024. Fitment must be verified against the engine nameplate and turbocharger nameplate due to variations in compressor cover orientation and wastegate actuator calibration across applications.