Holset 4044509 Turbocharger Assembly HX40W

The Holset 4044509 is an HX40W frame size turbocharger designed for Cummins 8.3 liter ISC, 6C8.3, GTA8.3, and QSL9 engine platforms. It utilizes a water-cooled bearing housing (H2 configuration) and an integrated wastegate actuator for boost pressure control. The unit features a forged milled compressor wheel and high-temperature turbine wheel assembly optimized for transient response in medium-duty and heavy-duty commercial vehicle duty cycles. This assembly serves as a direct OEM replacement for Cummins part numbers 4044509 and 4044508. Constructed from high-nickel alloy turbine housing and aluminum compressor housing, the rotating assembly is balanced to ISO standards for high-speed durability. The turbocharger interfaces with standard Cummins ISC exhaust flange and oil feed/drain ports. It is engineered for operation in on-highway truck and bus applications requiring EPA 1998/2004 emission compliance.