Everything you need and want to know about the Unimog 406
The unimog 406 is one of the best known unimogs. It was produced between 1963 and 1989 by Mercedes-Benz in Gaggenau. The 406 is the successor of the unimog 401 (including the 411). The 406 was the first medium-heavy unimog from Daimler-Benz. Many subsequent unimogs are partly inspired by the unimog 406. For many Unimog enthusiasts, the 406 with its application in agriculture (unimog agrar) and forestry is the classic Unimog, the 406 is not only used for agriculture but also by several armies worldwide.
The 406 (agrar) in agriculture
The first Unimog was designed for the farmer. The 406 is like the previous one primarily developed for the agricultural sector. Special Unimog attachments were developed during the development of agricultural implements. The Unimog can plow, sow, spread fertilizer, control weeds, mow grass and much more. Due to the high speed of 70 to 80 km / h and because the machine could do many tasks, the 406 was ideal for the farmer. The 406 had overtaken the normal tractor at one point and was the ideal agricultural machine. That is how Unimog agrar got its famous name worldwide.
The military Unimog 406
Most military unimogs come from the unimog 404 family, but there are also army unimogs from the 406 family. There are army unimogs that are still used today, for example in Argentina. This is a derived type 406, we are talking about the unimog 426. For the American army, Mercedes-Benz has developed the unimog 419 SEE (Small Emplacement Excavators). The 419 is technically similar to the 406, but is equipped with a heavier OM 352 engine. This engine has 110 HP.
The camper Unimog 406
The Unimog 406 is very popular with camper fanatics who convert their Unimog into camper Unimog.
Specifications of the Unimog 406
|Mass (approx.)||2650 kg||3100 kg||3600 kg|
|Length||4000 mm||4100 mm||4160 mm|
|Width||2000 mm||2030 mm||2130 mm|
|Height||2250 mm||2330 mm||2325 mm|
|Track width||1536 mm||1555 mm|
|Bed length||1950 mm|
|Bed width||1890 mm|
|Bed height||400 mm|
|Tyres||10–20″ (12.5–20″)||10.5–20″ (12.5–20″)|
|Engine model||OM 312.954||OM 352.919||OM 352.902||OM 353.902|
|Engine type||Straight-six Diesel, water-cooled|
|Fuel system||Precombustion chamber injection||Direct injection|
|Displacement||4.580 litre||5.675 litre|
|Bore × stroke||90 mm × 120 mm||97 mm × 128 mm|
|Rated power (DIN 70020)||65 PS (48 kW)||70 PS (51 kW)||80 PS (59 kW)||84 PS (62 kW)|
|Top speed||65 km/h||71 km/h||79 km/h|
Doka is short for “Doppel Kabine” which means dubbel cabine. The original intention was that the Unimog 406 would also be offered with a double cab as an addition to the convertible and the normal cab. This cabin was mainly equipped with the 406.145 model, an airplane tractor. The double cabin was also offered for other Unimog types. It is much more common for a Unimog 416 to be equipped with a double, which is often used as a chassis for motorhomes due to the longer wheelbase.
Of the 406 family, the unimog 416 is the most sold. This type is characterized by being the extended version of the 406. While the 406 has a wheelbase of 2380 mm, the 416 has a wheelbase distance of 2900 mm. At 2,900 mm, it has the same wheelbase as the long version of the Unimog 404. With more than 45,500 thousand unimogs 416 produced, this was the best-running product in the family.
The Unimog 403 is characterized as the cheaper alternative to the 406. The biggest difference is the engine. While the 406 is equipped with 6 cylinders, the 403 has only 4. This makes the Unimog 403 less powerful and also cheaper. Since they were also looking for a cheaper 416, the 413 was introduced. The 413 is a hybrid between the 403 and 416. It has the length of the 416 but the engine of the 403.
Changes of the 406
1966 – From U65 to U70
1968 – Gearbox change
F – Gearbox
It has four gears and two groups.
G – Gearbox
The standard gearbox was available with an additional intermediate gearbox for the model U 80 and U 84 (G-Gearbox). The intermediate gearbox simply doubles the number of gears, resulting in 2 × 6 forward and 2 × 2 reverse gears. Its gear lever has the three positions ″main gearbox″, ″intermediate gearbox″ and neutral. In addition to the additional intermediate gearbox, Daimler-Benz also offered a crawler-gearbox. The crawler-gearbox can be used with the first and second gear of every group of the main gearbox, it has two crawler gears, ″crawler″ and ″super crawler″, a neutral position and a ″main gearbox″ position.
1969 – Introducing the U80
The model U 80 was added to the model range in addition to the U 70. Also, the doors were made sturdier.
1971 – Following up the U84
The U80 was replaced with the U84. It was fitted with bigger, rectangular indicators, new tail lights, upgraded portal axles and a new aluminium bed.
1973 – New brake system
The drum brakes were replaced with disc brakes. With the introduction of the disc brakes, a dual-circuit brake system was installed and the rim colour was changed from red to black.