Description

Komatsu D900 Workshop Manual

I’ve been turning wrenches for 28 years, and I’ve seen what happens when a tech relies on a Chilton or a Haynes to rebuild a Komatsu D900 Workshop Manual engine. Mixed-up torque values, wrong timing specs, and a job that comes back on a hook. This is the real thing: 316 pages of original Komatsu documentation. It covers the D900 series engines – the D943 B, D962 B, D962 K, D963 B, D963 K, D963 A1, and D963 A2. Every engine variant gets its own section, showing both the injection pump side and the camshaft side. This manual isn’t a generic guide – it’s the same book dealer techs use. You get the exact orientation numbers, the part numbers for seals and gaskets, and the steps in the right order. No skipping steps.

On page 3, the preface explains how to use the orientation numbering system. That system is critical – every page has a 4-digit group and 3-digit subgroup. If you skip reading that, you’ll waste time flipping. Page 5 gives you the full contents list. You can see exactly where the fault finding chart lives (orientation 5000-201) and where the repair values start (5000-501).

Engine Overhaul: What’s Inside the 316 Pages

The manual is split into main groups: Engine general, Cylinder block, and more. Under Engine general you get descriptions, fault finding, engine speed adjustment, and mounting replacement. The cylinder block section covers liner removal and refitting, rear crankshaft oil seal replacement, and side covers. Every step comes with orientation numbers so you can cross-reference to the parts list. You’ll need a dial indicator to check camshaft end play – the manual gives the factory spec in metric, which I convert to thousandths for my feel.

Camshaft Side and Injection Pump Side: Two Separate Views

For each engine variant – D943 B through D963 A2 – you get two full-page illustrations: one from the injection pump side, one from the camshaft side. That means you can see exactly where the camshaft gear aligns with the injection pump drive. No guesswork. If you’re setting valve timing on a D963 K, you pull up orientation 5000-108 for the camshaft side and 5000-107 for the injection pump side. That precision saves you from bending a pushrod.

Fault Finding Chart – Start Here When It Won’t Run

Orientation 5000-201 holds a fault finding chart. It’s not a generic list – it’s specific to these direct-injection engines. It walks you through starting issues, smoke color, power loss, and noise. Each symptom points to a test or adjustment procedure later in the manual. I’ve used this chart to diagnose a stuck injection pump plunger in under an hour. The chart also cross-references to the technical data sections, so you can confirm your findings with real numbers.

Does This Manual Cover the D943 B Through D963 A2 Variants?

It covers every variant listed in the table of contents: D943 B (5000-501), D962 B (5000-511), D962 K (5000-521), D963 B (5000-531), D963 K (5000-541), D963 A1 (5000-551), and D963 A2 (5000-561). That includes dozer and other applications. If you have a D900-series engine, you’re covered. Each variant has its own repair values page – don’t mix them up. A D963 K uses different piston protrusion specs than a D962 B.

Cylinder Block Repairs: Liners, Oil Seals, and Side Covers

The cylinder block section (group 5100) gives you the factory procedure for removing and refitting cylinder liners. Wet liners need careful measuring and sealing – the manual specifies the sealant and installation depth. The rear crankshaft oil seal replacement (orientation 5100-404) is a common job. The manual tells you the exact seal driver depth and which side faces the oil. Side cover gasket replacement (5100-406) is also detailed. Don’t try to reuse old gaskets – the manual shows the correct sealant type and torque pattern for the bolts.

For transmission work, you need the same level of detail. See Manual Transmission for factory specs on manual gearboxes. The same attention to OEM data applies to Manual Transmission overhaul. Don’t rely on generic guides for either.

Related manuals for other Komatsu machines: Komatsu WA65-5 WA70-5 WA80-5 2005 Workshop Manual, Komatsu WH609-1E0 WH613-1E0 WH713-1E0 WH714H-1E0 WH716-1E0 Workshop Manual, and Komatsu PW95R-2 Workshop Manual – 520 Pages of Factory Specs.

If you’re rebuilding a D900 engine without this manual, you’re working blind. The factory specs for camshaft end play, injection pump timing, and cylinder head bolt torque are all in here. Access the Factory Manual from AutoRepairManuals and get the job done right.

What engine variants are covered?

D943 B, D962 B, D962 K, D963 B, D963 K, D963 A1, D963 A2.

Does this manual include torque specifications?

Yes, the general technical data sections for each variant include repair values, tolerances, and torque settings. For example, D943 B repair values are on orientation 5000-501. You’ll find cylinder head bolt torque, main bearing cap torque, connecting rod torque, camshaft bearing torque, and injection pump mounting torque. All values are factory OEM, not aftermarket approximations. If you don’t use these exact numbers, you risk stripping threads, warping the cylinder head, or causing a leak that leads to a blown gasket. That’s why I insist on factory data for every torque-critical fastener.

Is this a genuine OEM manual?

Yes, it’s the original Komatsu workshop manual, not a reprint or third-party copy.

How many pages?

316 pages, covering engine removal, disassembly, inspection, and reassembly with detailed illustrations and orientation numbers.