Description

Komatsu D155AX-5 2001 Service Manual

If you’re pulling a D155AX-5 into the bay and you don’t have this Komatsu D155AX-5 2001 Service Manual in your hand, you’re setting yourself up for headaches. I’ve seen guys guess on hydraulic pressures and end up blowing seals because they trusted a third-party reprint. That machine weighs over 80,000 lb – mistakes cost real money and can put someone in the hospital. This factory manual is what Komatsu shipped to dealer techs. 67 pages, printed in Japan in 2001, covers serial numbers 70001 and up.

What the TOC Tells You – Six Sections of Real Work

The manual is split into exactly six chapters. 01 GENERAL – that’s your safety decals, lubrication charts, and general specs. 10 STRUCTURE AND FUNCTION – the guts of the drive train, steering clutches, and final drives. 20 TESTING AND ADJUSTING – where you live when you’re diagnosing a low torque converter charge pressure. 30 DISASSEMBLY AND ASSEMBLY – step sequences for pulling the transmission or torque converter. 40 MAINTENANCE STANDARD – wear limits, clearance specs, and what’s scrap. 90 OTHERS – special tools, bolt torque charts, and electrical schematics. No filler. Every page is dense with numbers.

Testing and Adjusting – Where the Manual Earns Its Keep

Chapter 20 is the one you’ll wear out first. It gives you the test port locations for pilot pressure, steering clutch pressure, and torque converter charge pressure. It lists the required flow rates and pressures in psi – not converted, not rounded. You need to know that the charge pressure at the torque converter should be 85–114 psi at working temperature? That’s in there. If you try to set that with a generic manual, you’ll be chasing ghosts. This manual also tells you which gauge ranges to use, and it warns you about running with low oil level before you ever start the test. I’ve seen a guy burn up a torque converter because he skipped the oil level check on page 20-12. Don’t be that guy.

3 Reasons to Use the OEM Manual Over a Reprint

First, reprints often miss the revision marks. This manual has a list of revised pages starting on page 00-3. A page with a double dagger (‡) means it was replaced. If you buy a copy that doesn’t show those marks, you might be working from outdated specs. Second, the wiring diagrams in Chapter 90 are factory schematics – color-coded, with harness connector views. Third, Komatsu includes the exact part numbers for special tools. You won’t find that in a third-party PDF. Komatsu D155AX-5 Operators Manual – Factory OEM Operation & Maintenance covers daily operation, but this service manual is for the guy holding a wrench.

Disassembly and Assembly – Follow the Order or Pay Twice

Chapter 30 walks you through pulling the final drive, the transmission, and the steering clutches. It doesn’t say “remove the bolts” – it tells you the exact sequence and torque. For example, the final drive mounting bolts get torqued to 696 ft-lb. That’s not a suggestion. If you go by feel, you’ll distort the housing. The manual also includes notes on which parts must be replaced and which can be reused after cleaning. You’ll find a section on installing the torque converter: align the splines, check end play, then run the lockup test. Every step has a warning if there’s a safety catch – like draining the hydraulic tank before disconnecting lines to prevent high-pressure oil injection.

Audience Fit – Who Actually Needs This

If you’re a shop owner in Texas who does heavy equipment repairs, this manual is your baseline. If you’re a DIY landowner who owns a D155AX-5 and wants to do your own undercarriage adjustments, you need it too. But don’t buy it if you’re expecting generic maintenance advice. This is a factory service manual for the SA6D140E-2 or SA6D140E-3 engine. For engine-specific overhaul, Komatsu points you to the separate engine shop manual (6D140-2 or 140-3). The dozer manual covers everything else: the steering system, the blade controls, the final drives, and the air conditioner. For a beginner, I’d pair it with the Komatsu D155AX-5 Operators Manual – Factory Specs & Safety so you understand the controls before you start wrenching.

Source Validity – OEM vs Aftermarket

I’ve been turning wrenches for 28 years. I’ve bought aftermarket manuals that had torque specs off by 20%. Not here. This is a genuine Komatsu publication from 2001, printed in Japan. The page numbers match the factory parts catalog. The revision table on page 00-3 shows exactly which pages were updated. If you buy a reprint from some site that scanned a copy of a copy, you lose the revision marks and sometimes the edges of schematics. I only trust original OEM PDFs like this one. For reference on manual transmissions in general, you can read about Manual Transmission fundamentals, but for the D155AX-5, stick with Komatsu’s book.

Another common reference point for understanding power flow in heavy equipment is the Manual Transmission theory – it helps when diagnosing engagement issues. But again, the factory manual gives you the exact clearances and pressures for this specific machine.

FAQ

Does this manual cover the SA6D140E-2 engine overhaul?

No. It references the separate engine shop manual. This manual covers chassis, drivetrain, hydraulics, and controls.

What’s the correct torque for the final drive mounting bolts?

696 ft-lb per the disassembly chapter. Always check the revised pages in the front matter because Komatsu updated that spec on later serial numbers. The manual includes a list of revised pages with page numbers and revision marks so you know exactly which pages are current. If you have a printer, I recommend printing the revision list and taping it inside your toolbox lid.

Bottom line: if you’re going to tear into a D155AX-5, don’t waste time guessing. Access the Factory Manual and have the right numbers on the bench.

Related manuals you might need: Komatsu D155AX-5 2001 Workshop Manual – Factory OEM Specs for a broader workshop perspective.