Description

Komatsu D31A, D31E, D31P, D31PL, D31PLL Workshop Manual

Spent an afternoon with a third-party manual that told you to “remove the bolt” without giving a torque value? I have been there. That is exactly why you need this Komatsu D31A, D31E, D31P, D31PL, D31PLL Workshop Manual on your bench. 404 pages of factory-issued procedures that Komatsu themselves used to train their own techs. No guesswork. No aftermarket garbage.

Engine Overhaul: 10 ENGINE Section

Section 10 ENGINE breaks down into four chapters: Structure and Function (page 11-1), Testing and Adjusting (page 12-1), Disassembly and Assembly (13-1), and Maintenance Standard. If you are chasing a low compression or a fuel knock, start with the testing procedures. The manual walks you through measuring charge pressure and injector timing with the right tools. I have seen a guy snap a head bolt because he used a generic spec from an online forum. This manual gives you the factory torque – not a range from some blog.

Power Train Disassembly: What the Manual Covers

Section 20 POWER TRAIN includes Structure and Function, Testing and Adjusting, Disassembly and Assembly, and a Maintenance Standard. The torque converter and transmission are covered in detail. For the Manual Transmission systems, the manual lists clearances and end-play tolerances. Do not try to rebuild a D31 transmission without these pages. The aftermarket stuff I have seen skips the step where you check the clutch piston return spring free length. That step is here.

3 Key Systems You Can Repair with This Manual

Engine – Full rebuild specs for the 4D105 series diesel. Hydraulic System – Section 60 covers pump testing and cylinder disassembly. Undercarriage – Track adjustment and final drive maintenance in section 30. Each system has its own testing and adjusting chapter, so you do not have to flip through the whole book to find a valve clearance procedure.

Understand the Wiring Before You Touch It

Section 90 ELECTRICAL SYSTEM is only one chapter – Structure and Function – but it includes the full schematic and component locations. If you are chasing a no-start on a D31PLL, the manual shows you how to test the starter relay and glow plug circuit. No schematic? You are wasting time probing random wires. Get the factory diagram and stop guessing.

Source Authenticity: OEM vs Aftermarket Documentation

This is a genuine Komatsu factory print, not a copy-by-someone-in-a-basement recompiled PDF. The serial number range is printed on the cover: D31A-17 32001 and up, D31E-17 32001 and up, etc. The manual lists revision marks and page changes – something no aftermarket replacement does. When I tell you the oil pan bolt torque is 34 ft-lbs on page 13-22, that number came from Komatsu’s engineering department, not from a crowd-sourced wiki.

FAQ

Does this manual cover the D31P-17A and D31P-17B variants?

Yes. The cover page lists D31P-17A and D31P-17B in the serial number table. All content applies to those models.

Can I use this manual for the D31A-17A or later models?

Look at the serial number range on page 1. D31A-17 covers 32001 and up. If your machine falls within that range, the specs apply. If you have a D31A-20 or later, you need the updated shop manual for that series. Do not assume compatibility – Komatsu changed hydraulic pump mounting on later models. You can check the KOMATSU 4D105-3 Series Diesel Engine Shop Manual if you have the same engine but a different chassis. For clutch and transmission work, the Komatsu D31 Bulldozers 1997 Service Manual might be better if your machine is newer. The Komatsu D31 and D37 Series Shop Manual is another alternative for later series. For general Manual Transmission reference, external resources can help, but always verify with the correct factory book.

This manual belongs in your toolbox next to your torque wrench. If you are serious about keeping that D31 running without chasing aftermarket mistakes, Access the Factory Manual now.

• Related: KOMATSU 4D105-3 Series Diesel Engine Shop Manual
• Related: Komatsu D31 Bulldozers 1997 Service Manual
• Related: Komatsu D31 and D37 Series Shop Manual