The Unimog 421 is a vehicle of the Mercedes-Benz Unimog series, made by Daimler-Benz. In total, 18,995 units of the Unimog 421 were built from 1966 to 1989 in the Mercedes-Benz Gaggenau plant. It is a medium-sized vehicle bigger than the traditional Unimog 411, but smaller than the Unimog 406. Introduction of new heavy models and Unimog 411 production ceasing in the mid-1970s changed the Unimog 421's role in the Unimog lineup; it became the predecessor of the light Unimog series and thus succeeded the Unimog 411.
Both short and long wheelbase versions, as well as "front half only" OEM part versions, were made. Technically, the Unimog 421 is based on the Unimog 406 and Unimog 411. The plane ladder frame and axles are Unimog 411 parts, and the engines used for the 421-series are also passenger car engines. Cab and gearbox are Unimog 406-related. The 421 closed cab version looks almost exactly like a 406-series cab, but the cabrio version is a bit more narrow and "squat". A 406-series can be differentiated from a 421-series by the position of the air-intake: A 421-series has the air-intake on the right-hand side of the bonnet, and a 406-series on the left-hand side.
In Argentina, a copy of the Unimog 421, the 431-series, was produced under licence. From 1969 to 1971, 601 cabrios and 152 closed cab units of the Unimog 431 were made. Daimler-Benz produced CKD-kits in Gaggenau, which were then shipped to Argentina for manufacture. The 431-series was fitted with a engine, but has the short wheelbase – this combination was not available for the original 421-series.
Engines
The 421-series was made with straight-four precombustion chamber Diesel engines. Prototypes included, four different engines were used, which are all passenger car engines.
EngineDisplacementRated powerYearsOM 636 1964–1965(Prototypes only)OM 621 1966–1968OM 615 1968–1970OM 616 – 1970–1989
Types of the 421-series In total 20 different types of the 421-series were made, out of which four were made as OEM parts for other manufacturers.
Mercedes-Benz types TypeModelCabWheelbaseRated powerNumber manufacturedNotes421.122U40, U45Cabrio ,2.647 421.123U40, U45Closed cab ,3.215 421.124U52Cabrio1.145 421.125U52Closed cab1.995 421.126U60, U600LCabrio 4 U 600 L: Crew cab 421.128U60, U600LCabrio3.252 U 600 L: Crew cab 421.129U60, U600LClosed cab599 U 600 L: Crew cab 421.130U40T, U45T, U55TCabrio –,, 6 OEM part 421.131U40T, U45T, U55TClosed cab – ,,210 OEM part 421.132U60T, U600TCabrio –35 OEM part 421.133U60T, U600TClosed cab –372 OEM part 421.140U52, U600Cabrio1.805 421.141U52, U600Closed cab3.368 421.162U60Cabrio13 421.163U60Closed cab25 421.310U421Cabrio304
Types made for third party manufacturers Several Unimog 421 types were custom-made as OEM parts for third party manufacturers.
TypeThird party manufacturerModelEngine powerNumber manufactured 421.160HoesKnickschlepper 421.164Werner Forst- und Industrietechnik Uniknick UK52, UK60,75 421.170TractortecnicUnitrac UT4550 421.172TrenkleTremo250
Technical specifications
U 40U 45U 52U 60Years1966–19711966–19711970–19881971–1988Mass Permissible maximum mass? Length Width Height Wheelbase Track widthBed length Bed widthBed board wall height Tyres10,5–18″ 6PR Engine typeOM 621OM 615OM 616 Engine designWater-cooled straight-four Diesel engine Fuel systemPrecombustion chamber injectionDisplacement Bore × Stroke Rated power (DIN 70020)Top speedSource
Gallery
References
Unimog-Community: Unimog U 421 [1966 bis 1989]
Carl-Heinz Vogler: Unimog 411 – Typengeschichte und Technik. GeraMond-Verlag, München. 2014. . p. 22
Carl-Heinz Vogler: Unimog 406 – Typengeschichte und Technik. GeraMond-Verlag, München. 2016. . p. 113
Peter Kautz: Mercedes-Benz Unimog 421
Daimler AG: Baureihe 421
Carl-Heinz Vogler: Typenatlas Unimog. Alle Unimog-Klassiker seit 1946 bis 1993. GeraMond, München 2015, . p. 89
External links
Historical Daimler-Benz commercial video on YouTube; 9:39 min