Description

HATZ 2W35, 3W35, 3W35T, 4W35, 4W35T Workshop Manual – Factory Specs for the Diesel Engine

If you are tearing into a HATZ 2W35, 3W35, 3W35T, 4W35, 4W35T Workshop Manual engine, you need the real factory documentation. I have seen guys ruin a perfectly good injection pump because they guessed at the start-of-delivery adjustment. That mistake costs time and parts. This 72-page book from HATZ gives you the exact data for all five models: 2W35, 3W35, 3W35T, 4W35, and 4W35T. It covers the basic engine, the water pump, unit injectors, camshaft, timing chain, and all the tables you will need for injection pump timing and torque wrench settings. Want to avoid a crankcase leak? The sealing plan is in here. Need to trace a wire? The full electrical circuit diagrams with HATZ wiring designations are included. This is not some aftermarket reprint – it is the original PDF scanned from the binder that HATZ sent to dealers.

HATZ 2W35, 3W35, 3W35T, 4W35, 4W35T Workshop Manual – What’s Inside

Open the file and you will see the Contents on page 2 and 4, then the Foreword on page 5 where HATZ explicitly states: “Use only genuine HATZ parts for repairs!” I could not agree more – aftermarket seals and off-spec bolts will bite you. Chapter 1 covers general info: engine illustrations, technical data, type plate data (including EPA/Carb), jointing materials, and a list of special tools you will need. Do not skip the tool list – using a universal puller where a specific tool is called for can break the camshaft. Chapter 3 is where the real work happens: replacing the water pump, replacing unit injectors, adjusting the start of delivery, and replacing the camshaft and timing chain. Each procedure has step-by-step instructions written for a trained mechanic. If you are a DIYer, read the whole procedure twice before touching anything.

Camshaft and Timing Chain Replacement

This manual devotes a full section to the camshaft and timing chain. You will find the exact installation order, the chain tension specifications, and the alignment marks. HATZ expects you to use factory tools for timing chain removal – do not improvise with a pry bar. The manual also tells you how to check the camshaft end float. If you get it wrong, the injection timing drifts and the engine will not run right. Look at page 4 of the Table of Contents: the torque wrench settings are listed in the Tables section. I always keep that page marked when I am reassembling a 3W35T after an injector swap.

3 Critical Systems Covered in the Tables Section

• Injection pump timing and injection pressure – tested values per model, not generic numbers.
• Torque wrench settings – for every critical fastener: cylinder head, connecting rod, flywheel. Use them.
• Electrical circuit diagrams and wiring designations – color codes and terminal numbers for the HATZ system. No guesswork when troubleshooting a no-start.

These tables alone can save you from pulling your hair out. For example, the 4W35T turbo engine uses different injection pressure than the naturally aspirated 4W35. The manual shows both.

Torque Wrench Settings: What the Manual Says

Page 4 lists “Torque wrench settings” under Chapter 4. That is where you will find the foot-pounds (or Newton-meters if you work in metric) for every bolt that matters. I have seen a water pump failure because someone used 18 ft-lbs instead of 22 ft-lbs on the 2W35. That leak will kill the bearing. The manual also gives the tightening sequence for the crankcase joint face sealing plan – you follow that pattern or you will get oil weeping. HATZ designed these engines for industrial use; they do not tolerate sloppy assembly.

Check the Wiring Before You Start

Electrical gremlins in a HATZ diesel are rare, but when they show up, the wiring diagrams in this manual are the only reliable source. The “Code designations in circuit diagrams” and “HATZ wiring designations” tables explain every wire color and connector pin. If you need to trace a circuit, find the diagram for your specific model (2W35, 3W35, etc.) and start there. Do not rely on generic diesel wiring charts – they will not match the 4W35T’s glow plug relay setup.

Why You Should Trust This Manual (and Not Aftermarket Copies)

I have seen aftermarket manuals that list the wrong torque for the 3W35 connecting rod bolts. That is a catastrophic failure waiting to happen. This HATZ manual is the original OEM print – the same one that factory-trained technicians use. It includes the jointing material specifications (type of sealant and bonding agent) and the exact special tool numbers. If you need a companion for routine maintenance, grab the HATZ 1D41 1D50 1D81 1D90 Instruction Book for operating instructions. For parts identification, the HATZ Diesel 108 Series Spare Parts Catalog and HATZ Diesel 1B20, 1B30 Original Spare Parts Catalog are helpful cross-references. And if you are working on the drivetrain, the basics of a Manual Transmission apply, but for the engine itself, this workshop manual is all you need.

Does this manual cover the 3W35T model?

Yes, the 3W35T is explicitly listed in the title and contents.

I am a beginner – can I use this manual?

It assumes a trained mechanic, but if you have basic tools and follow safety warnings, you can do repairs. It gives step-by-step procedures for specific jobs like water pump replacement and injector adjustment. However, it does not cover basic maintenance like oil changes. You will need to refer to the instruction book for that. The manual expects you to know standard workshop practices – for example, cleaning parts and replacing O-rings is assumed. If you are comfortable with engine disassembly and using torque wrenches, you can handle it. Just do not skip the sealing plan and wiring diagrams. Access the manual and read the Foreword first – it tells you what tools are required and reminds you that only genuine HATZ parts are acceptable. Start with a small job like the water pump on a 2W35 to build confidence.

What torque values are listed?

All critical fasteners: cylinder head, connecting rod, flywheel, injection pump, and more – in foot-pounds.

How is the manual organized?

Four chapters: General (specs, tools), Basic Engine (repair procedures), Tables (torque, wiring, sealing plan), plus illustrations and circuit diagrams for each model.

Stop second-guessing your repair. Get the factory data that HATZ engineers wrote. Access the Factory Manual from AutoRepairManuals and keep it on your tablet or printed at the workbench. Your 2W35, 3W35, 3W35T, 4W35, or 4W35T engine will thank you with years of reliable service.