Description

Mitsubishi 4DQ5 1991 Parts Catalog – OEM Factory Specs

If you’re rebuilding a Mitsubishi 4DQ5 1991 Parts Catalog is your lifeline. This isn’t a generic aftermarket compilation. It’s the official factory document, 128 pages of exploded diagrams and part numbers that Mitsubishi Heavy Industries published in August 1991. I’ve seen mechanics strip threads because they guessed on a bolt grade. Don’t be that guy. Every component from the cylinder head down to the crankshaft is laid out with exact reference numbers. The table of contents lists 17 major sections covering engine body, inlet & exhaust, oil system, cooling, fuel system, engine electrical, control system, and repair parts. You get the overhaul gasket kit breakdown and a numerical parts index. This is the same book the dealer parts counter uses.

Who Needs a 128-Page Parts Catalog?

If you own a power unit (PU2500, PU3000), a drive generator (DG1500/1800, DG3000), or a packaged generator (PG35K, PG40K) powered by the Mitsubishi 4DQ5, this catalog is for you. DIYers rebuilding in their home garage will find the exploded views a lot clearer than squinting at a scanned microfiche. Professional mechanics need the precise part numbers to avoid returns and downtime. Fleet shops maintaining multiple 4DQ5 units will save hours with the numerical index. The catalog covers engine serial numbers from 172005 and up. If your engine falls in that range, you are covered.

Engine Body: Cylinder Head to Crankshaft

The engine body section starts with 01 CYLINDER HEAD and works its way through VALVE MECHANISM (04-01), ROCKER COVER & CAMSHAFT (04-02), CRANKCASE ASSY (07-01) and the separate CRANKCASE (07-02). Then you get TIMING GEAR CASE & TIMING GEAR (11), FLYWHEEL HOUSING (12), OIL PAN (13), ENGINE MOUNTING (14), PISTON & CONNECTING-ROD (17), CRANKSHAFT & FLYWHEEL (20), and ACCESSORY DRIVE (25). Each subsection has a detailed exploded view with callouts. For example, the valve mechanism shows the valve, spring, retainer, and key with individual part numbers. If you need a camshaft or crankshaft, the exact factory part is listed.

Fuel System and Electrical: OEM Part Numbers You Can Trust

The fuel system is broken into nine subsections: FUEL INJECTION PUMP GENERAL (61-01), FUEL SYSTEM (61-02), NOZZLE (61-03), specific injection pump variants (61-04 through 61-05), governors (61-06 through 61-08), and FEED PUMP (61-09). Engine electrical covers STARTER (12V-2KW and 24V-3.2KW) and ALTERNATOR (12V-35A). If you’re replacing a nozzle or a fuel filter, you’ll find the OEM part number. No guessing. For a broader view of the industry, see Automotive Industry Overview. And if you need a battery, check Automotive Battery for general specs, but for the 4DQ5 starter and alternator, use this catalog.

Aftermarket Cross-References vs Factory Documentation

Aftermarket parts catalogs often reuse the same generic drawings across multiple engine families. They might list a part that “fits” but doesn’t match the factory spec. This Mitsubishi catalog has the official maker’s name, table of symbols, and a thorough nomenclature section. The book states explicitly: “MITSUBISHI GENUINE PARTS should be used exclusively.” I trust that. You should too. The catalog includes a TABLE OF BOLT, W/WASHER at the back – the exact bolt sizes and washer types for every assembly. That alone is worth the price of admission. If you work on other Mitsubishi diesels, look at Mitsubishi S3L2 2009 Parts Catalog – OEM Factory Specs or Mitsubishi S6A3-PTA PTK 1991 Parts Catalog – Factory OEM Specs. There’s also Mitsubishi 4DQ50 Diesel Engine Parts Catalog for a related engine family.

The numerical parts index alone saves hours.

4 Questions About the Mitsubishi 4DQ5 Parts Catalog

Does this catalog include torque specifications?

No, it does not. Torque specs are in the service manual.

How do I read the part numbers?

The catalog uses a reference number system. Each part has a REF-NO. On the sample page you’ll see columns for REF-NO, PART NO., DESCRIPTION, and QTY. Cross-reference the REF-NO to the numerical index at the back to get the factory part number. The TABLE OF SYMBOLS & ABBREVIATIONS explains every code used in the diagrams. Once you’ve studied the sample page – the catalog includes a SAMPLE OF PARTS CATALOGUE section – you’ll navigate it quickly. The bookmarks in the PDF link directly to each section, so you can jump from 01 CYLINDER HEAD to 20 CRANKSHAFT & FLYWHEEL in one click.

Can I use this catalog for a 4DQ5 built before 1991?

The catalog is dated August 1991 and applies to engine serial numbers 172005 and up. For earlier engines, a different edition may be needed. Check your engine plate.

Is the PDF searchable?

The original file is a scanned PDF with OCR. The text is searchable for keywords like “piston” or “crankshaft”. The bookmarks link directly to sections, so navigation is fast.

If you are rebuilding a Mitsubishi 4DQ5 and want to order the right parts the first time, you need factory documentation. Don’t rely on a parts store’s computer that shows a generic image. Access the Factory Manual.