Unimog 401

Mercedes Benz
Unimog 401
Unimog 401
Manufacturer:	Daimler-Benz AG
Sales designation:	Unimog Unimog U 25
Production period:	1953-1956
Previous model:	Unimog 2010
Successor:	Unimog 411
Technical specifications
Engines:	OM 636 (diesel, 1767 cm 3 )
Power:	18.5 kW
Length:	3520 mm
Width:	1630 mm
Height:	2050 mm
Wheelbase:	1720-2120 mm
Payload:	1 t
Perm. Total weight:	3.15 t

The Unimog 401 is a four-wheel drive vehicle of the Unimog series of Mercedes-Benz , which by its design as a tractor, work machine and equipment carrier can be used universally. It was built at the Mercedes-Benz plant in Gaggenau and replaced the Unimog in 2010 . From 1953 to 1956, 10,928 401/402 vehicles were built. The 401 was initially built in an open version with a convertible top, from September 1953 also with a closed cabin, the so-called frog eye , built by Westfalia . The main difference between the Unimog 402 and the 401 is the longer wheelbase of 2120 mm. Both were replaced by the Unimog 411 , which was built with both the short and the long wheelbase.

history

The designer Albert Friedrich developed immediately after the war the university salinization Mo tor g et up instrument, the Daimler-Benz initially did not want to produce. At the Boehringer machine factory in Göppingen , two samples were then made, one of which was presented in August 1948 at the agricultural exhibition in Frankfurt. Due to the high response, Boehringer initiated series production; By the end of 1950, 600 copies of this Unimog 70200 had been produced, the trademark of which was a stylized ox head with horns in the shape of a "U". At the end of 1950, Daimler-Benz took over the complete production facilities including the Boehringer employees and began production of the first Unimog at the Gaggenau plant in June 1951 . The Unimog now produced by Daimler-Benz in Gaggenau belonged to the 2010 series, and in 1953 it was replaced by the 401. There was hardly any technical difference, but the Unimog 401 was the first to receive a Mercedes star.

technology

The Unimog 401 is a compact, approximately 3.50 meter long vehicle with a U-profile ladder frame , rigid portal axles at the front and rear, and four wheels of the same size that are driven by means of a drive gear. The front and rear axles are guided on drawbars and panhard bars . They have coil springs with hydraulic shock absorbers . The tires of the Unimog are all-purpose tires of size 6.5–20, which are designed for off-road and road driving. The vehicle is braked with a hydraulically actuated brake system that acts on the brake drums on all wheels. The Unimog 401 has a wheelbase of 1720 mm, the Unimog 402 a wheelbase of 2120 mm.

Unimog 401: Cutaway model of the drive train in the Unimog Museum

engine and gears

The engine is taken from the passenger car range. It is the OM 636 VI , a Reihenvierzylinder- prechamber -Saugdieselmotor with lateral camshaft and 1767 cm ³ capacity, the power for the Unimog of 40 hp (29.5 kW) to 25 hp (18.5 kW) at 2350 min ^-1 was throttled. The water-cooled motor is installed in the center of the front and tilted slightly backwards. It is started with an electric starter.

OM 636 engine of the Unimog 401

The transmission is a mechanical dog gear with six forward and two reverse gears from Daimler-Benz. The Unimog 401 is all-wheel drive, the front-wheel drive can be switched on and off while driving without using the clutch. The differentials of the front and rear axles can be locked. The power is transmitted from the engine to the gearbox via a single-disk dry clutch from Fichtel & Sachs. On request, there was an additional creeper gearbox with two gears.

Equipment and accessories

The electrical system includes a 12 V Bosch alternator with an output of 150 W. It charges a 12 V / 105 Ah lead-acid battery. The Unimog has two headlights at the front, taillights at the rear, electric indicators on the sides and electric wipers on the windscreen. It also has an electric horn and an optional socket for trailer lighting.

At the rear of the Unimog there is a flatbed with an area of ​​2.25 m ² on which a payload of one ton can be loaded. An automatic spring-loaded trailer coupling at the rear and a hitch at the front were standard. The vehicle has a drawbar for attachments .

For power take-off could for 401 forward and backward depending on a power take-off are installed 9611 that deals with standardized according to DIN 540 min ^-1 rotates, the power output corresponds to approximately 22 hp (16 kW). Furthermore, a pulley with a diameter of 315 mm could be installed on the right, also with an output power of 22 HP (16 kW). A spare wheel was also available on request and the wheels on the rear axle could be fitted with double tires for a surcharge. A trailer braking system was also available. Other accessories included a cable winch, a cutter bar and air compressors.

The Unimog 2010 initially only offered an open driver's seat with a weather hood, a folding windshield, removable side panels and a fixed rear wall. This version was painted in Unimog green . When it was renamed Unimog 401, the variant with a closed all-steel cab was introduced. The version with weather cover was now called Type A , with all-steel cab type A / F . Similarly, the vehicles with trailer braking systems are named as version B (with convertible top) and as version B / F (with all-steel cab). Vehicles with an all-steel cab could be delivered in Unimog green , light gray and Mercedes blue .

Technical specifications

Unimog 402 with long wheelbase (2170 mm) and rear tipper

Unimog 401 frog eye with all-steel cab from Westfalia

Parameters	Unimog 401
Dimensions and weights
Gauge	1270 mm 1470 mm (after repositioning the wheels)
wheelbase	1720 mm
Ground clearance	380 mm
length	3520 mm
width	1630 mm
height	2050 mm (with hood)
Turning circle diameter	7600 mm
Loading platform	1.5 × 1.5 m, 2.25 m 2
Empty weight	1680 kg
payload	1000 kg
Max. Total mass	3150 kg
Powertrain
Power transmission on	Rear wheels, front-wheel drive can be activated
transmission	Daimler-Benz six-speed claw transmission, two reverse gears
coupling	Single-disc dry clutch from Fichtel & Sachs
Top speed	53 km / h
Fuel consumption	10 l / 100 km
engine
Engine designation	OM 636 VI
Engine type	Rows - four-cylinder - pre-chamber - OHV - naturally aspirated
cooling	water
Bore × stroke	75 × 100 mm
Displacement	1767 cm 3
Compression ratio	19: 1
rated capacity	25 DIN-PS (18.5 kW) at 2350 min -1
Max. Torque	10.3 kpm (101 Nm) at 2000 min -1

literature

• Werner Oswald : Mercedes-Benz trucks and buses 1886-1986. Motorbuch Verlag Stuttgart, 2008, ISBN 978-3-613-02943-9 .
• Carl-Heinz Vogler: Unimog type atlas. All Unimog classics from 1946 to 1993. GeraMond, Munich 2015, ISBN 978-3-86245-026-8 , p. 33 ff.

Individual evidence

1. ↑ Vogler, p. 34
2. ↑ ^{a b} Werner Oswald, p. 321.
3. ↑ ^{a b c} Unimog Community: Unimog U 401
4. ↑ Vogler, p. 15
5. ↑ Vogler, p. 25
6. ↑ Unimog U 2010 - Unimog Community
7. ↑ ^{a b c d e f} Daimler-Benz AG: Technical data Unimog 401 1955.
8. ↑ ^{a b c} Daimler-Benz AG: Price list for Unimog 401 1955

Web links

Commons : Unimog 401  - Collection of pictures, videos and audio files