Doosan DL300-3, DL350-3 2012 Workshop Manual – 1230 Pages of Factory Specs

If you are wrenching on a Doosan DL300-3 or DL350-3 wheel loader without the factory workshop manual, you are working blind. I have seen too many guys guess at hydraulic line torques or skip the accumulator depressurization step because they think they know it. That is how you get hurt or break a 500-dollar part. This Doosan DL300-3, DL350-3 2012 Workshop Manual runs 1230 pages for a reason: Doosan packed every system into one book. Page 1 carries the official title and serial number range (10001 and up). Page 3 shows the table of contents – safety, specifications, general maintenance, engine, drivetrain, brake, steering – each cross‑referenced by SP part number. No aftermarket abridgment. Original OEM print.

Safety Section: 40+ Pages of Machine‑Specific Warnings

Before you touch a wrench, read the safety block. It covers wheel loader hazards: pressurized fluids, hot coolant, ROPS, electrical shock, and the correct way to block the bucket. Doosan spells out burn prevention, fire prevention, and what to do when working on slopes. There is a whole subsection on rubber containing fluorides – if you torch a hydraulic hose without knowing that, you inhale toxic smoke. This is the stuff that keeps you alive. You also get transportation rules, loading/unloading instructions, and battery boost starting procedure. No guesswork.

Specifications for DL300-3 and DL350-3 – Dimensions, Capacities, and Curves

The specs chapter gives you component locations, general specifications, engine performance curves, working range dimensions, bucket capacities, stability data, and approximate material weights. If you need to know the lift capacity at full turn or the weight of a heaped bucket of gravel, it is in there. The section is called “Specification for DL300-3 / DL350-3” and includes both models side by side. You can compare the DL300-3 and DL350-3 in the same table.

Standard Torques – Metric and U.S. Fasteners

This is where the manual earns its keep on the workbench. Doosan provides torque values for standard metric fasteners, standard U.S. fasteners, Type 8 phosphate coated hardware, hose clamps, ORFS swivel nuts, and split flanges. There is also a section on torque wrench extension tools and how to calculate torque multiplication. If you are using a crowsfoot or a universal joint, you need that math. The tables give both foot‑pounds and inch‑pounds. No having to convert units or guess thread pitches.

Engine Overhaul: DC9 Diesel and Coolant Heater Option

The engine chapter covers the Doosan DC9 diesel – inspection, cleaning, special tools. There is also a subsection for the engine coolant heater (option). If you are pulling the head or checking ring end gap, the manual walks through the procedure with factory clearances. Do not use a generic diesel manual; the DC9 has specific torque sequences and injector timing marks. This is the same information the dealer techs get.

Drivetrain Diagnostics: ZF Transmissions and Axle Specs

Two transmission options are documented: the ZF 4WG and the optional ZF 5WG. Each has its own SP number and separate removal, installation, and disassembly procedures. The manual also includes transmission error codes (ZF) – if the dash throws a code, you look it up here instead of calling the dealer. Axle coverage is for the ZF MT‑L 3085 II and 3095 II, plus driveshaft specs. For general transmission knowledge, refer to Manual Transmission on Wikipedia, but for the exact ZF overhaul you need Doosan’s word. The related manuals for other Doosan models include the Doosan Solar 340LC-V 2002 Workshop Manual – 656 Pages OEM and the Doosan DX140W, DX160W 2006 Workshop Manual – 1180 Pages, as well as the Doosan DH130W 2023 Workshop Manual – 470 Pages OEM. If you work on multiple machines, stack them on the bench.

What About the Brake and Steering Systems?

The brake chapter covers service brake, supply valve, charging block, parking brake, brake pedal valve, and accumulator. If you are bleeding brakes or replacing a charge block, you need the exact bleed sequence and pressure specs. Steering includes the power steering system, steering unit, steering pump, flow amplifier, jerk softener and accumulator. Doosan also includes emergency steering procedures. For additional reading on hydraulic steering principles, see Manual Transmission – no, that is drivetrain; for steering, there is plenty in this manual. Do not mix up the two external sources.

Frequently Asked Questions

Does this manual cover both the DL300-3 and DL350-3?

Yes. It covers both models in the same volume.

What year is this manual for?

Published April 2012, applicable to serial number 10001 and up.

Are the torque specs in imperial or metric?

The manual includes both metric and U.S. fastener torque tables. It also covers ORFS swivel nut torque and split flanges. If you need a refresher on standard fastener torque, check the table of contents on page 3. The torque wrench extension tool section explains how to adjust when using adapters – critical for engine main bearing caps and axle fasteners where over‑torquing can crack the housing. Doosan even gives torque values for hose clamps, which most aftermarket books skip entirely.

Is this a reprint or an OEM document?

This is an original factory scan, not an aftermarket reprint.

You have the serial number range, the chapter list, and the page count. Download the Factory Manual and keep it next to the oil filter wrench. You will refer to it more than any Chilton or Haynes.