Komatsu SA6D108-1A-T(S/N 10001-UP)

The SA6D108-1A-T is a bare industrial diesel engine, not a complete machine: a mechanically governed, turbocharged and aftercooled inline-six built on Komatsu's 108-series block, sharing the 7.15-liter displacement, 108 x 130 mm bore and stroke, and the S/N 10001-UP serial block with the base SA6D108-1A generation and its other arrangement variants. Komatsu supplied this engine across two unrelated machine families of the 1990s and early 2000s: the PC300-5/PC300LC-5/PC300HD-5/PC310-5 hydraulic excavator range, roughly a 30-33 tonne class built through the decade, and the WA320-3/WA380-3/WA420-3 wheel loader range, roughly a 14-20 tonne class built into the early 2000s, plus stationary engine and generator-set packages sold outside any Komatsu machine chassis. Rated output sits in the approximately 154 kW (207 HP) class at a governed speed near 1,950 rpm, delivered through a jerk-type mechanical injection pump with no engine control module. It replaced larger-displacement, non-aftercooled Komatsu diesels used on the preceding excavator and wheel loader generations, including the S6D125 block on the PC300-3, trading displacement for a lighter turbocharged-and-aftercooled design at a similar power class.

Within the 108-series block, Komatsu's early-1990s update moved from larger, simpler mechanical diesels to this smaller, turbocharged-and-aftercooled arrangement, the SA6D108-1A generation on the 10001-UP serial block, cataloged with several trailing arrangement suffixes, including this T build, for different host and accessory-drive configurations sharing the same core casting. Komatsu then carried the same cylinder block forward into its next generation as the electronically controlled SAA6D108E, fitted to the following PC300-6/PC350-6 excavators and later WA-series loaders, adding an engine control module and electronic governing this mechanical generation never had. In the used and parts market today, that mechanical simplicity is the draw: no control module to fault, injection-pump and governor work follows straightforward mechanical procedures, and because arrangement variants share a cylinder block, liners, and core machining with the wider 1A family, rebuild kits and core components stay easier to source than for many single-application industrial blocks. Buyers sourcing one of these engines, whether pulled from an excavator, a wheel loader, or a genset package, should confirm the exact arrangement suffix and serial number against the engine data plate before ordering parts, since arrangement-specific components do not always cross over.

Below: full specifications, fluids & capacities, the factory service schedule, common service parts, verified fault codes, what owners discuss, attachment guidance, the complete assembly directory, and a serial-number reference. Complete parts lists with full OEM part numbers, exploded diagrams, quantities, and fitment data are available free in Heavy Parts AI.