Mitsubishi 4D56 engine factory workshop and repair manual 1991 onwards on PDF can be viewed using free PDF reader like,. It is compressed as a zip file which you can extract with File size 6 Mb Searchable document with bookmarks.
Mitsubishi L200 4x4 Parts
Manual Contents Specifications Special Tools Drive Belt and Timing Belt Intake and Exhaust Manifolds Turbocharger Water pump Thermostat hose and pipe Procker Arms Rocker shaft and Camshaft Cylinder Head Valves and Valve Spring Front Case, Silent Shaft and Oil Pan Piston and connecting rod Crankshaft Flywheel and Drive Plate Cylinder Block About the 4D5 engine The Mitsubishi Astron or 4G5 engine, is a series of straight-four internal combustion engines first built by Mitsubishi Motors in 1972. Engine displacement ranged from 1.8 to 2.6 litres, making it one of the largest four-cylinder engines of its time. It employed a hemispherical cylinder head, chain-driven single overhead camshaft (SOHC) and eight valves (two per cylinder). United States passenger car versions had a small secondary intake valve referred to as the 'Jet Valve'. This valve induced swirl in the intake charge, enabling the use of leaner fuel/air mixtures for lower emissions. It was designed as a cartridge containing the valve spring and seat which simply screwed into a threaded hole in the head, similar to a spark plug but inside the cam cover.
The rocker arms for the intake valve were widened on the valve end to accommodate the cartridge, which was equipped with a very soft valve spring in order to avoid wear on the camshaft intake lobe. Modifications to the head were thereby reduced as the Jet Valve negated the necessity for a three-valve-per-cylinder design. In 1975, the Astron 80 introduced a system dubbed 'Silent Shaft': the first use of twin balance shafts in a modern engine.
It followed the designs of Frederick Lanchester, whose original patents Mitsubishi had obtained, and proved influential as Fiat/Lancia, Saab and Porsche all licensed this technology. The 4D5 engine is a range of four-cylinder belt-driven overhead camshaft diesel engines which were part of the 'Astron' family, and introduced in 1980 in the then new fifth generation Galant. As the first turbodiesel to be offered in a Japanese passenger car, it proved popular in the emerging SUV and minivan markets where Mitsubishi was highly successful, until superseded by the 4M4 range in 1993. However, production of the 4D5 (4D56) continued throughout the 1990s as a lower-cost option than the more modern powerplants. Until now it is still in production, but made into a modern powerplant by putting a common rail direct injection fuel system into the engine.