Komatsu D50A-2, D60A-2, D70A-2 Operators Manual – 107 Pages

Description

Twenty-eight years in this trade, and I still get calls from guys who torqued a cylinder head to the wrong spec because they used a reprint manual. Don’t be that guy. The Komatsu D50A-2, D60A-2, D70A-2 Operators Manual is the factory document – 107 pages of exactly what Komatsu engineers wrote. No guesswork, no “close enough.” If you are maintaining a D50A-2, D60A-2, or D70A-2 lift truck, this is the only manual you should have on your bench.

Komatsu D50A-2, D60A-2, D70A-2 Operators Manual – Engine Service and Valve Clearance

The engine section is where most mistakes happen. This manual walks you through valve clearance adjustment step by step. It includes the exact specs – not a range, not “tighten until it feels right.” The factory procedure for drive belt tension, idle speed, injection timing, and compression pressure are all there. I’ve done this job a hundred times and having the numbers from page 26 saves you from pulling a head twice. You need the charge pressure? Page 26. That page also gives you general tightening torque for the whole machine – differential, drive axle, wheel bearings, brake drum. Use it.

Don’t skip the safety section.

What Torque Values Are Listed?

Torque specs are broken down by system so you don’t have to guess. The power transfer group, torque converter, wheel brakes – each has its own torque table in the specifications. If you are reassembling the final drive, those numbers are critical. I have seen hubs come loose because someone used a generic chart out of a workshop manual that wasn’t Komatsu-specific. This manual ends that. The values are for the D50A-2, D60A-2, and D70A-2 platforms specifically, not some broad range. Every fastener gets the correct ft-lb. You want to sleep at night after the job? Use the factory torque.

3 Safety Sections You Must Read

First, page 2 has the Proposition 65 warning – a legal requirement in California. More important: the safety section starting page 4 covers tipover survival, operator restraint, and maintenance safety. Read it before you put someone on that machine. The manual explicitly warns against operating without training. I don’t care if you’ve run forklifts for years – the Komatsu system has specific hazards that are covered in the general hazard information on page 9. Fork adjustment, refueling procedures, storage – all included. Safety is not optional on a 10,000-pound lift truck.

Fuel System: Injection Timing and Nozzle Service

The fuel system covers injection pump removal and replacement, timing adjustment, and the nozzle body/needle valve disassembly. If you are replacing injectors, you need the factory procedure for nozzle seat cleaning and pressure testing – that’s step-by-step, not a two-line note. The symptom-related diagnostic procedure means you can troubleshoot by matching what you see to the manual’s logic. Hard starting? Low power? Black smoke? The manual walks you through the injection timing check and the nozzle inspection. The fuel stop system is also detailed. I’ve seen shops spend three hours on a no-start that the manual could have solved in thirty minutes using the diagnostic tree.

If you are new to this driveline, start with the Manual Transmission operation explanation. Then apply it to the Manual Transmission hydraulic control system in this manual – it covers power flow in high and low speed forward and reverse, inching valve operation, and the valve function chart.

Why OEM Documentation Matters

Aftermarket manuals pull specs from multiple sources and often round values or miss steps. The Komatsu factory manual was printed from the original engineering files. Every spec, every diagram, every tolerance was verified by the manufacturer. That matters when you are setting valve lash on a D60A-2 engine. Use a non-OEM spec and you will be pulling the head again in 500 hours. The 107 pages are the exact same content Komatsu sent to dealers. No reprint, no generic compilation. If you are a shop owner, you want liability protection – the factory manual is the evidence that you followed the correct procedure.

Verify the Starting System Wiring

The starting system includes wiring diagrams and component tests. You get the off-machine no-load test for the starting motor and the on-machine diagnosis procedure. If the starter drags, you trace the problem through the magnetic switch circuit – not by replacing parts randomly. The symptom list and diagnostic tree save you time and money. I’ve had techs call me because they swapped a starter three times only to find a corroded ground – this manual would have shown them the test procedure on the first page. The charging system section is equally thorough: alternator on-vehicle service and removal/replacement are covered with Komatsu-specific data.

For other Komatsu models, check out Komatsu WH609-1E0 – WH716-1E0 Operators Manual | 272 Pages OEM and Komatsu WD900-3 2004 Operators Manual – Factory OEM Specs. Also see Komatsu WB146-5 WB146PS-5 2006 Operators Manual – OEM Safety & Maintenance.

Frequently Asked Questions

Does this manual cover the Komatsu D70A-2 model?

Yes, it covers all three models D50A-2, D60A-2 and D70A-2. One manual for the series.

Is this a reprint or a factory OEM document?

This is the original factory PDF from Komatsu. It is not a scanned reprint or a third-party compilation. The page quality matches the original printed manual.

What torque specifications are included?

General tightening torque, wheel bearing torque, brake drum diameter specs, differential and drive axle torque, wheel brake torque, and power transfer group torque. Also torque converter and wheel hub values. All on page 26.

Can I use this manual to troubleshoot engine problems?

Absolutely. The engine section includes a symptom-related diagnostic procedure. You look up the symptom (e.g., hard starting, low power) and follow the diagnostic tree. Then it directs you to on-vehicle service steps for valve clearance, injection timing, compression pressure, and more. The fuel system has its own symptom table for nozzle and pump issues. This is not a generic troubleshooting guide – it is specific to the D50A-2 series engine. You save hours of guesswork because the factory already did the logic. I have used this manual to diagnose a no-start on a D60A-2 in under twenty minutes by following the injection timing check. The steps are written so a home garage enthusiast can do them, but the detail is enough for a professional shop. Don’t rely on memory – use the book.

This is the document you need to keep your Komatsu running without breakdowns. Access the Factory Manual now and put it on your shop tablet.