1963: Unimog 406 – start of the medium product range
1966: Completely new programme arrangement
1974: U 120 rings in the heavy Unimog product range
1976: Product expansion and new sales classifications
1985: Start of new Unimog product ranges 407 to 437
At the start of the sixties, the small 'basic Unimog' did not come up to the increased demand for more comfort and the somewhat altered demands of the market. Also the Unimog S as a mainly military vehicle was not always the proper alternative for civilian needs. As a result, from 1963 on the first medium product range with the classification 406 was introduced. The wheelbase of the new Mercedes-Benz Unimog was now 2380 mm (7.8 ft).
Product range 406: advent of a new performance and size category
Once again larger diesel engines were to be found under the Unimog’s short bonnet: 65 hp from an engine with six cylinders, and very shortly afterwards also from the legendary, large-capacity six-cylinder diesel engine OM 312 with its 5.7 l (5700 cc) – this was the new standard for engine performance. The new Unimog was then called after its horsepower and known as the U 65. Daimler-Benz supplemented its programme with an additional product range 406 as a genuine all-rounder for both offroad operations and road transport and this opened up a whole new host of opportunities for the Universal-Motor-Gerät, for instance as a very powerful tractor vehicle.
Very soon other product ranges join the 406
In 1966, the company rearranged its Unimog programme. The small Mercedes-Benz Unimog U 34 from the early days was now joined by the medium product range 406 with the U 70 version, which was then developed into the U 80 and U 84. Parallel to this development, Daimler-Benz began to build product range 416 with its 2900 mm (9.4 ft) wheelbase, just like the Unimog S.
In between the original Unimog and the medium product range, Daimler-Benz then introduced a light product range 421/403, which was later supplemented by product range 413. The individual models varied according to wheelbase and engine – some of which were derived from car engines (product range 421/U 40 with 2.2 l /
2200 cc) and others from the commercial vehicle sector (403/U 54 with 3.8 l / 3800 cc).
Product range 425 – the heavy Unimog product range
The next Unimog product range came into being in 1974. The series production began the following year. Daimler-Benz crowned its programme of very versatile tractor and work machines with an additional heavy-duty performance class, designed with a striking new angular cab and a large not very sloping bonnet at the front: the U 120 from product range 425. The design of this cab had hardly changed in its basic form for more than a quarter of a century.
Product range 425 started off with 120 hp (a short time later with 125 hp as U 125), 2810 mm (9.2 ft) wheelbase and 9.0 t max. weight. Product range 435 also went into production for the armed forces in 1976 as the successor to the Unimog S.
New product classifications determined
During this period, Daimler-Benz restructured its model classifications. Models with the classic rounded form were now known as U 600 L, U 800 L, U 900 and U 1100 L. Models with the new more angular form were now known as Unimog U 1000, U 1300 L, U 1500 and the flagship U 1700 L with an engine performance of 124 kW (168 hp). The letter "L" indicated models with a long wheelbase.
Whereas Unimog vehicles with the rounded cab were the lighter production range, the new product ranges were differentiated according to their maximum overall weight as medium and heavy. And finally, the long-serving Unimog S still rounded off the programme, even though in clearly decreasing numbers, unaltered and as the only petrol-driven vehicle.
Disc brakes long before the trucks
A special mention has to be made of one particular technical highlight: With the exception of the entry-level model, at the time the product classifications were rearranged all Mercedes-Benz Unimog vehicles were fitted with disc brakes on all wheels – many years before this safety feature became standard for normal trucks. The efforts of those in charge of Unimog production to find a solution with a suitable vehicle for every requirement a customer might have were also rewarded with a new record: In 1977 the 200,000th Unimog rolled off the line in Gaggenau.
Complete facelift for product ranges 407, 417 and 427
During the following years, the Unimog programme remained more or less unaltered. However, between 1985 and 1988 things really happened fast in the models policy: With its product ranges 407, 417, 427 and 437 Daimler-Benz completely renewed its Unimog programme. The basis was the cab from the medium and heavy product ranges and altered dimensions, wheelbases, understructure, weights and engines resulted in a completely new chassis.
The programme now covered everything from the small, compact Mercedes-Benz Unimog U 600 with a performance of 44 kW (60 hp) and a maximum weight of 4.5 t right up to the Unimog U 2400 whose six litre (6000 cc) engine came up with a record performance of 177 kW (240 hp).
Performance almost ten times more than at the beginning
From 1993 on, the programme was crowned by the Unimog U 2450 L 6x6, a four-wheel drive three-axle vehicle. The inventors of the original Unimog more than 40 years previously could never in their wildest dreams have imagined such a model. It pays just to look at the difference in engine performance: In comparison with the first Unimog, the new top model had almost ten times more power.