Komatsu 180-27-00021 Floating Seal Assembly

The 180-27-00021 floating seal assembly, also known as a mechanical face seal or duo-cone seal, is engineered for Komatsu final drive and travel reduction units. It consists of two precision-machined metal seal rings and two elastomer toric rings. The metal rings are manufactured from high-carbon chromium alloy steel such as SAE 52100 or NI-HARD (ASTM A532) with a hardness rating of 58-65 HRC for high wear resistance. The elastomer components utilize NBR compound with 60-65 Shore A hardness for oil resistance and sealing integrity. This seal retains lubricating oil within the final drive planetary gear set while excluding abrasive contaminants, water, and debris in severe earthmoving applications. It is a direct replacement for Komatsu OEM part numbers 180-27-00021 and 56D-33-00050. Verified applications include hydraulic excavators PC220-1, PC490-11, PC650-1, PC650-5, PC850-8, bulldozers D355A-3, D355A-5, D355C-3, and articulated dump trucks HM250-2, HM300-1, HM300-2, HM300-3 powered by SA6D140-2 and S6D155-4 diesel engines.