Hitachi 9115208 Idler Assembly

The Idler Assembly 9115208 is an OEM-specification front idler designed for Hitachi hydraulic excavators including the EX270, EX300, EX300-2, and EX300-3 series. The component maintains track chain tension and alignment within the undercarriage system. The idler body is manufactured from cast alloy steel, utilizing grades such as 35Mn, 35MnB, or 40Cr, followed by specialized heat treatment to achieve surface hardness and core toughness required for high-load cyclic contact. The assembly includes the idler shell, shaft, brackets, and sealed bearing group configured for direct bolt-on installation to the track adjuster yoke. Cross-reference interchangeability extends to part numbers 9115208V, 9151028, AT159063, AT178256V, SI824, 08-10-0025, and 73188044. Application coverage includes Hitachi EX270, EX300, EX285, EX400, EX870, UH07, UH08, ZAX270, ZAX330, ZAX350 models, as well as compatible John Deere 270LC, 792DLC, 892DLC, 892E-LC, Fiat-Allis, and New Holland equipment utilizing the same undercarriage geometry.