In a class of their own: Mercedes-Benz L 406 D and L 408

Jan 14, 2002
It first saw the light of day in the transitional period between the economic miracle and modern times. In January 1967, Daimler-Benz AG, as it was known then, presented the new L 406 D and L 408 large-capacity vans as well as the O 309 minibus which was built on the same basis. The so-called “ Düsseldorfer Transporter” (Düsseldorf vans) replaced the popular L 319 post-war van, added considerably to its potential and stylishly continued the success story of what had been Mercedes-Benz’ first large-capacity vans. Up until the end of production in 1986, just under half a million units rolled off the production line at the plant in Düsseldorf.
Universal genius and quick-change artist
Larger and more powerful than a delivery van, more easily maneuverable and lighter than a truck: these characteristics were the key to its success. Düsseldorf vans, with their high payload capacity, were in a class of their own and set the standards in their sector from the outset.
If these vans had never existed, somebody would have to have invented them. The German postal service ordered numerous panel vans, painted a deep yellow, for delivering parcels. The new large-capacity van was also welcomed by furniture stores who usually had voluminous box-bodies fitted on the Düsseldorf van chassis and appreciated the fact that the combinations still had a low loading edge.On the other hand, the crewcab pickup was a hit with construction workers. The boss and his team could all fit into the cab, while you could stow anything from a sack of cement to roofing panels on the pickup's platform, i.e. everything you needed for the job could come with you. Quite often, a compressor or even a whole site caravan was attached onto the trailer coupling hook.
The workaholic
As a mixture of bus and truck, the crewcab model was also popular with municipal services who also had to transport teams of people and a lot of equipment at the same time. No wonder that the fire service quickly discovered the benefits of the large-capacity van for its own purposes and gladly made use of the speedy gasoline-engined L 408 as a crew fire-fighting vehicle.
As if this wasn’t enough, the Düsseldorf vans even made the banks move. Converted into a mobile branch, the large-capacity van served as a savings bank, cruising through the villages. In general, those who had products to sell on markets and, therefore, relied on mobility were delighted with the new model which could so excellently be converted into a mobile shop and did not even collapse under a generous amount of stock on board.
It goes without saying that the Düsseldorf vans also made a career as mini-buses. They were ideal for shuttle services. In far-off countries they were allrounders, functioning as enormous taxis or compact expedition vehicles. Bodybuilders such as Ernst Auwärter conjured up luxurious club buses from Düsseldorf vans, such as the legendary Teamstar.
Timeless design with elegant functionality
The timeless stylistic rhetoric of the design, which made a clean break with the emphasized roundedness of its predecessor, the L 319, was entirely new. With elegant and practical charm, the emphasis of the new design was on functionality. The “button nose” hood testified to a very compact design with an engine which extended a short way into the cab. However, in keeping with the light-weight truck series presented in 1965, the steering axle was positioned far towards the front, facilitating lower and more com-fortable entry into the vehicle.
There was a generosity with regard to visibility quite unknown before in van design. Only thin pillars acted as connecting elements between the high, slanting windscreen and the lateral quarterlights. The action was taking place around the driver, almost like standing at a pulpit, and so, for conditions at that time, the driver had everything wonderfully in view.
Highly rated, sound engineering
However, Mercedes-Benz ensured continuity in the tried and tested com-ponents that did the work under this timeless outer shell. The successful predecessor, the L 319, of which around 120,000 units had been produced, had already demonstrated that robust and sound engineering was very popular with the customers. And so the L 406 D diesel model came on the scene in 1967, supplied with a well known two-liter prechamber diesel engine called the OM 621, which had already powered the L 319 and developed 55 hp. Likewise, the 80 hp 2.2 liter gasoline engine in the L 408 – which, however, hardly featured in the sales statistics – was already known from the L 319.
Highly improved ride comfort
And yet the ride comfort had increased considerably. Certainly in the sensitive ambulance and rescue vehicle sector, the Düsseldorf vans nearly had a monopoly for their weight category. Through extensive detailed work and finetuning, the engineers had succeeded in fundamentally improving the handling and ride qualities compared to those of its predecessor. U-section frame side members with cross-members and leaf-sprung rigid axles front and back were the distinguishing marks of the chassis on the new generation of vans, which continued in the successful tradition of their predecessors in this respect.
Modular assembly system for maximum versatilityFrom the start, the new Düsseldorf vans’ trump card was their great variability. The secret to this was a versatile modular assembly system which was refined over the years. The Düsseldorf plant produced the van in a choice of three weight categories, 3490, 4000 and 4600 kilograms. Six chassis, with or without cabs, were provided for purpose-built bodies and vehicles.
With short-wheelbase panel vans, the customer had the choice between a normal roof giving an interior cargo space height of 1600 millimeters and a slightly higher roof giving 1750 millimeters height in the cargo area. By con-trast, Mercedes offered the panel van with the long wheelbase exclusively in the particularly spacious, higher variant with 1750 millimeters interior height. Hinged and sliding doors were also on offer as well as a great variety of door combinations.
Steadily rising engine output and gross weight
In 1968, the OM 615 prechamber diesel engine with 2.2 liter displacement and an output of 60 hp replaced the original OM 621 two-liter engine. In 1974, the new OM 616 diesel engine, which had a displacement of 2.4 liters and an output of 65 hp, came on the scene. The model designations changed accordingly. Instead of L 406 D, from then on this newly strengthened Düsseldorf van was known as L 407 D. In 1982 a 72 hp variant of the OM 616 entered the field.
The base engine had already had competition from an engine with greater displacement for a long time. From 1968 onwards a new model called L 408 D enriched the program. The L 408 D’s 80 hp were developed by a unit from the legendary 300 engine series, which itself had its roots in the conventional L 3250 postwar truck of 1949. This engine series is still being produced in Mannheim, Brazil and Iran. New weight versions accompanied this 3.8 liter engine: the large-capacity van conquered the five and six ton categories.
New six-cylinder engine with 130 hp
The desire to be freed from the constraints of the truck had thus been aroused. In 1977, Mercedes-Benz extended the choice of engines by adding a big-brother OM 352 six-cylinder unit with an output of 130 hp to the OM 314 four-cylinder engine. Meanwhile, the maximum permissible weight for the six-tonner had risen from 5900 kilograms (1970) to 6500 kilograms (1973). More than ever before, the 5.7 liter six-cylinder inline engine with 130 hp rated output made it possible for the 6.5-tonner to perform impressively, even in difficult circumstances, e.g. with a heavy site caravan in tow.
Extra-long wheelbase: 4100 millimeters
And yet it wasn’t just engines that grew in diversity and power. In 1972, a particularly long wheelbase of 4100 millimeters extended the possibilities for the L 508 D and L 608 D pickup models. The panel vans of the same model were also able to benefit from this wheelbase from 1974 onwards. An extra-high panel van version made it possible to make use of 1900 millimeters of interior height instead of the previous maximum of 1750 millimeters.
In 1980, the five and six ton panel van versions with 4100 millimeter wheelbases also grew in width. As an alternative to the 2100 millimeter wide models and especially for volume-oriented customers, Mercedes-Benz offered another model with an exterior width of 2400 millimeters and interior height of 1930 millimeters. The load volume increased by almost 20 percent from 17.5 to 20.8 cubic meters. The German postal service wel-comed this with open arms.
The O 309 bus also profited from the long 4100 millimeter wheelbase which became available in the bus sector from 1975 and which from 1979 could be combined with the option of a particularly spacious variant, with an exterior width of 2450 millimeters instead of the usual 2100 millimeters. “25 +1” instead of “21 + 1” seats were among the pleasing effects of the long 4100 millimeter wheelbase in passenger transport.
Careful refinements
Careful refinements throughout the long course of their production period ensured that the Düsseldorf vans always remained up-to-date. In 1977, for example, the series went through an extensive model refinement process which resulted in the addition of modern taillights and rubber-protected bumpers to its outward appearance. On the inside, life was made easier for the driver by a new dashboard and wind-down windows instead of the slid-ing windows which had been common up till then. The quarterlights in the doors were made into ventilation windows. In addition to this, there were new control levers and handles as well as a steering wheel with a pleasant-to-the-touch, easy-to-grip cover.
Finally, in 1981 came a new, anthracite-colored plastic radiator grill and a wide bumper made of plastic. At the same time, the Düsseldorf plant also refurbished the interior paneling of the large-capacity vans, which greatly reduced the noise level in the cab.
Parts kits even sent to South America
The Düsseldorf vans proved to be virtually indestructible, not only individu-ally but also as a species. Production, which had started in 1967, lasted for almost 20 years (without counting 20 units produced in 1966) and only stopped in 1986. Precisely 496,447 units with the internal code numbers 309 and 310 came into the big wide world and made a name for them-selves during this period. Mercedes-Benz also delivered almost 50,000 parts kits for assembly to plants in Argentina, Spain, Tunisia, Iran and Turkey.
Tried-and-tested design to this day
The question of whether the successor, the T2 presented in 1986, had a hard act to follow or whether, in fact, the nest was already made for it, would be purely academic. One thing is sure: above the Sprinter and T1 model series, the T2, with gross weight ratings of up to 7.5 tons, covered an even wider range of applications than its predecessor and continued to capitalize on the niche between the classic van and a light-weight truck.
Even though, over time, the model series has gone through further modifi-cations and now bears the name Vario, it still successfully carries on exactly this tradition. Its individual “button nose” directly reminds one of the Düsseldorf vans presented in 1967 – this typical characteristic lives on in the Vario large-capacity van series today. Just like the Düsseldorf van and the T2 before it, the Mercedes Vario is proving to be a true allrounder and is still forming a class of its own.