It is produced alongside the heavy-duty, off-road lorry-like Unimog 437.4, which features a different technical design.

Throughout its more than 20-year-long production, the Unimog 405 has been developed into an implement carrier family that comprises various different variants, models, and types.

The types' designation in Unimog 405 is indicative of frame length (and thus wheelbase), the engine model, as well as the maximum permissible axle load.

For instance, the Unimog U 318's types' designation (3000 mm wheelbase, OM 934 LA engine, low-payload axles) is 405.104.

It features chrome bumpers, exhaust tips, an all-black exterior, new body panels, and a giant steel rollover protection bar.

It is equipped with the 205 kW version of the OM 906 six-cylinder engine and the automatic shifting option for the gearbox; the top speed is 120 km/h.

[6] In late 2005, Mercedes-Benz announced that the Brabus Unimog U 500 Black Edition would be put into series production if demand for the vehicle existed.

[7] One year later, German news paper Die Welt wrote that six Unimog U Black Edition were sold, with three being in production.

[11] The new Unimog series was supposed to have four options for mounting implements: In front, in back, on the bed, and in between the axles.

Eventually, in 1996, the board of directors and the works council agreed upon developing and producing the new Unimog series at the Mercedes-Benz-Werk Gaggenau.

They have about 500 parts that are different compared to the German Unimog 405 types, most notably, an OM 906 engine tuned to comply with US emissions regulations.

[16] 2006 brought changes to European motor vehicle legislation which eventually resulted in the Unimog 405 being updated.

To comply with the then-new Euro IV emissions standard, the Unimog 405 was equipped with a selective catalytic reduction catalyst.

To manage the high torque output, Daimler Truck Holding designed a new gearbox for the U 435 and U 535 models, the UG 130.

[25] Like in conventional lorries, the frame has bolted closed cross profiles which result in a high torsion stiffness.

[31] In the either-hand drive version, the entire steering column, gauge cluster, and pedals can be moved by the driver without special tools.

The bonnet is unusually short and steep for a short-bonnet lorry, and the cab is fitted with a rather large, slightly curved but almost upright windscreen.

[34] An "extending"[A 4] passenger side door – which gives an implement operator better visibility – was available as a factory option.

It is similar to the UG 100 gearbox in terms of design, but is capable of accepting a higher input torque of around 1300 N·m.

[23] For road-rail use, the Unimog 405 is offered with a combined dry single-disc clutch and hydrodynamic torque converter.

This design allows setting off with a very high tow hitch load (e.g. laden trucks) without wearing out the dry single-disc clutch.

Its electronic control system allows indefinitely adjustable speeds of 0...25 km/h,[A 8] and it is operated either by a hand lever, or with the accelerator pedal.

The OM 900 series consists of four- and six-cylinder Diesel engines and has been made in several different versions.

[45] In order to achieve high efficiency, Daimler-Benz installed a single wastegate turbocharger and an air-to-air intercooler.

At 1300/min, the OM 906's BMEP reaches its maximum of 2.17 MPa which is achieved through a high turbo boost of 285 kPa.

For reducing nitrogen oxides from the exhaust, the Euro IV and V models were fitted with a selective catalytic reduction device.

The exhaust camshaft is fitted with the variable valve timing system from the Mercedes-Benz M 272 V6 Otto engine.

In the open circuit, a high volumetric flow rate is maintained which requires a big hydraulic oil reservoir.

Implements that do not require a high volume flow rate can be powered with the more compact closed circuit.

Both the accelerator pedal and the shift lever are electronic and have no mechanical connection to the unit injection pumps or gearbox.