Description

Komatsu WA320-3 Workshop Manual

If you’re wrenching on a WA320-3 without the factory documentation, you’re burning billable hours and risking a comeback. I’ve seen guys pull a transmission thinking they could eyeball the shim stack – then wonder why the charge pressure is off by 50 psi. This Komatsu WA320-3 Workshop Manual is 852 pages of the actual procedures Komatsu wrote for their own techs. Not a reprint. Not a third-party summary. OEM print, start to finish. You want the torque for the differential carrier bolts? It’s in there. The bleed procedure for the brake accumulator? Page 20-something. Stop guessing – get the factory data.

Safety Section: Why You Read It First

Page 00-3 has a full safety chapter that covers lifting points, high-pressure hydraulic hazards, and proper jack stand placement. Komatsu doesn’t mess around – they specify rated slings and shackles for every component lift. The section on ROPS cab integrity is something you don’t skip if you’re welding or modifying anything near the structure. Aftermarket manuals leave this out because they assume you already know. I assume you don’t. Read it.

Power Train and Transmission: 7 Subsystems Covered

The Structure and Function section (chapter 10) breaks down the torque converter, transmission, drive shaft, differential, final drive, and axle pivot. Hydraulic circuit diagrams for the transmission and the work equipment are included – not simplified cartoons, but real ISO-standard symbols with port numbers. The transmission control valve spool identification alone can save you a teardown. If you’re chasing a hesitation in the forward-reverse shuttle, the manual walks you through the Komatsu WA320-3 Shop Manual pressure taps on page 73 (approximate). Compare your readings to the standard value table in chapter 20.

Tests and Adjustments: Page 20-1 Onward

Chapter 20 is where you live if you diagnose. Valve lash adjustment specs, compression test procedure, injection timing check, fan belt tension – all with pound-feet and inches where applicable. They list the special tools needed for each test: differential pressure gauge kit, tachometer, timing light. No guessing which adapter fits. The brake disc wear check uses a dial indicator and the manual tells you the max runout. You’re not supposed to “feel” it – you measure it.

Does This Manual Cover the Electrical System?

Yes, and it’s not a wiring diagram that looks like spaghetti thrown at a wall. The electrical section includes the machine monitor system (main and maintenance monitors), automatic transmission shift control, E.C.S.S. (electronically controlled suspension system), and the starter and preheat circuits. There’s a dedicated diagram for the parking brake solenoid valve and emergency release. If your WA320-3 won’t start because the controller is locking out the shift, the manual shows the interlock logic. Manual Transmission systems don’t have that complexity – but on this loader, the transmission is electronic over hydraulic. You need the manufacturer’s diagnostic tree.

Torque Tables and Conversion: Factory Specs Only

Right after the preface there’s a standard torque table and conversion charts. Komatsu gives you both Newton-meters and pound-feet, plus a column for bolt grade. I don’t care how many years you’ve been turning wrenches – you torque a main bearing cap by feel and you’ll be buying a new block. The manual also covers coating materials and sealants: ThreeBond 1211 for these O-rings, Loctite 242 for those threads. Aftermarket reprints often omit the exact chemical spec, leaving you guessing. This manual doesn’t.

Who Needs This Manual?

If you own a WA320-3 wheel loader and you do your own maintenance, you’re the target. The manual is written for a mechanic with basic tools but it expects you to follow the steps in order. Beginners: don’t skip the safety section. Pros: use chapter 30 (disassembly and assembly) for overhaul procedures – it includes clearances, press fits, and assembly lube requirements. The manual also covers the S6D108 engine separately, but this volume focuses on the loader drivetrain, hydraulics, and frame. For similar machines, check Komatsu WA65-5 WA70-5 WA80-5 2005 Workshop Manual or Komatsu WH609-1E0 WH613-1E0 WH713-1E0 WH714H-1E0 WH716-1E0 Workshop Manual if you work on those models.

Source Validity: OEM Komatsu vs Aftermarket

This is the genuine Komatsu workshop manual – the one their dealers use. The part number on the cover matches the original. Aftermarket reprints from third-party vendors often lose resolution on the hydraulic schematics or reverse the page order. I’ve seen a reprint that had the brake test procedure mixed into the AC section. Waste of time. This copy is scanned from the original binder – all 852 pages, including the fold-out circuit diagrams. Manual Transmission comparisons don’t apply here; this is factory authorized.

Frequently Asked Questions

Is this manual in English?

Most of the content is in Spanish as published by Komatsu for the Latin American market. The diagrams and torque values are international standard – you don’t need Spanish to read a number. If you need English, check the preface; some copies include bilingual safety notes.

Does it cover the S6D108 engine overhaul?

No. The manual references the separate engine workshop manual for the series 108. This volume covers everything bolted to that engine – transmission, hydraulics, electrical, and chassis. Find the engine manual separately if you’re rebuilding the block.

What page has the transmission charge pressure spec?

Around page 20-15 in the standard value tables for the chassis. The exact page may vary between printings, but look in chapter 20 under “Transmission and torque converter pressures.” It’s listed in psi and bar.

Can I print this PDF?

Yes, you can print single pages or the whole document from your computer. The file is a clear scan, not a locked DRM copy. Use a binder or put it on a tablet in a waterproof sleeve. I prefer paper on the bench – grease and screens don’t mix.

Stop burning time on aftermarket summaries that omit the critical data. Access the Factory Manual – 852 pages of Komatsu’s own specs, diagrams, and procedures. Your WA320-3 deserves the same documentation a dealer tech uses. Get it here.