Description

Komatsu 107E-2 Workshop Manual – 291 Pages of Factory Specifications for Engine Rebuild and Repair

Working on a Komatsu 107E-2 Workshop Manual engine without the factory manual is a gamble I’ve seen cost a full weekend and a cylinder head. Over 28 years in a six-bay shop here in San Antonio, I’ve had to fix too many jobs that went sideways because someone trusted a third-party summary. This 291-page OEM document is what Komatsu’s own techs use. It’s printed from the original factory files, not a scanned reprint with missing pages.

Open the index and you’ll land on section 00 – Index and foreword. That opens with the important safety notice and how to read the shop manual. Most guys skip that. Don’t. Page 00-10 explains the symbols and how procedures are laid out. After that, section 01 gives you all specs – applicable machines, general view, engine performance curve. Need to know if your engine has the right exhaust gas regulation for your region? That’s on 01-3.

Fuel System and Electrical: Two Areas You Don’t Wing

Section 10 covers structure and function. Inside that, the fuel system gets its own subsection with a parts layout drawing and a circuit diagram. You’ll see the supply pump, fuel cooler, pre-filter, main filter – all with factory routing. The electrical equipment section covers the alternator, starting motor, intake air heater, engine wiring harness, engine controller, and sensors. If you’ve ever chased a no-start on a 107E-2, you know the wiring harness diagram is worth the price of the manual alone. The manual also lists how to read the electric wire code – page 00-29 – which saves you from tracing wires with a multimeter for two hours.

For transmission work, grab a dedicated Manual Transmission guide – this manual covers only the engine. But the engine’s electrical system interacts with the rest of the machine, so having the factory pinouts and sensor resistance tables here prevents chasing ghosts.

Standard Torque Values and Service Limits

Section 20 is the standard value table. It includes a standard service value table for the engine – running-in standards and performance test standards. If you’re rebuilding a 107E-2, you need the clearance specs for cylinder head, cylinder block, crankshaft, piston, connecting rod, timing gear, camshaft, valves. Those are all in section 60 – maintenance standard. The standard tightening torque table is on page 00-35. I’ve torqued thousands of head bolts; using the wrong value for the M10 or M12 bolts on this engine will pull threads or cause a leak. This table gives you the ft-lbs directly – no conversion needed.

3 Reasons to Choose OEM Documentation Over Aftermarket Copies

First, the OEM manual routes every procedure through the factory “how to read the shop manual” guidelines – you get consistent steps, correct sequence, and proper special tool references. Aftermarket manuals often combine procedures from multiple engine models and miss critical warnings like handling fuel system devices (page 00-14) or handling hydraulic equipment (page 00-16). Second, the torque specs and standard values in this manual were verified by Komatsu’s engineers – not compiled from forum posts. Third, the 291 pages include full disassembly and assembly procedures (section 50) with coating materials list and special tool sketches. Third-party PDFs rarely include exploded views of the vibration damper or the KCCV ventilator details.

Does the 107E-2 Workshop Manual Cover Disassembly and Assembly?

Yes. Section 50 starts with general information on disassembly and assembly – how to read that section, coating materials list, special tool list, and sketches of special tools. Then it walks through general disassembly of the engine, general assembly, removal and installation of the supply pump unit alone, and front/rear oil seal replacement procedures. If you’re pulling the engine to swap a supply pump or reseal the front cover, this section gives you the order and the torque sequence. Skip a step and you’ll be ordering a new gasket set – ask me how I know.

For other Komatsu models, check the Komatsu WA65-5 WA70-5 WA80-5 2005 Workshop Manual or the Komatsu WH609-1E0 WH613-1E0 WH713-1E0 WH714H-1E0 WH716-1E0 Workshop Manual. If you need a larger machine engine manual, the Komatsu PW95R-2 Workshop Manual – 520 Pages of Factory Specs covers a different series but shares similar diesel engine principles.

One more thing: the manual includes a conversion table (page 00-43) for metric to imperial. That keeps your torque wrench in ft-lbs without mental math.

That’s it.

Frequently Asked Questions

Does this manual cover the complete engine or just the fuel system?

It covers the entire 107E-2 engine: intake/exhaust, EGR, KDPF, lubrication, cooling, fuel, electrical, and all internal components.

Can I use this manual for the 107E-1 engine?

No. This is specifically for the 107E-2 series. The 107E-1 has different fuel system and electrical controller.

Is the manual a true factory OEM document or a reprint?

It is a digital copy of the original Komatsu shop manual – page numbers, diagrams, and torque tables are identical to what a Komatsu dealer tech would pull up. No third-party edits or reprints.

What if I need the wiring diagram for the engine controller?

Turn to the electrical equipment section in “Structure and function.” There you’ll find the engine wiring harness layout, sensor locations, and the engine controller pinout. The manual also explains how to read the electric wire code so you can trace any circuit. If you still can’t find it, the index at the front lists every component. I’ve used that index to jump straight to the alternator and starting motor pages when diagnosing a crank-no-start. The 291 pages are organized so you don’t flip through half the book to find one sensor.

If you’re serious about keeping that 107E-2 running right, stop relying on memory or a tablet with generic specs. Access the Factory Manual and put the real information on your bench. For a transmission overhaul, you’ll also need a proper Manual Transmission manual – but for the engine, this is the only one you can trust.