It was introduced to fill the gap between the smaller, Datsun Bluebird based Datsun Truck, and heavier load capacity Nissans under the Nissan Diesel brand, like the 80-series trucks.

This may have been due to the decision to market it under the unfamiliar Nissan name, as well as "Junior" not being a very suitable name for a large, heavier payload truck.

The B40 Junior was launched in October 1956 as a medium-size truck which could carry a 1.75-ton load and three passengers.

While not as space efficient as a cabover, the bonneted layout provided a considerably better ride.

While retaining the looks of the B40-series, featuring only a changed grille and a somewhat longer wheelbase of 2,610 mm (103 in), the new B140 series did have the all new G-series engine.

The new engine, which it shared with the Cedric, was of nearly exactly the same displacement as the old one, at 1,488 cc, but had 71 PS (52 kW) at 5,000 rpm.

[6] The B140 was introduced in April 1960, at the same time as the cabover version, the Caball, received the new engine.

Also in 1962, the Junior and Caball were also joined with the Datsun Cablight, an integration from former Japanese automobile manufacturer called Tokyu Kogyo Kurogane which Nissan acquired.

[7] It was much more modern in design, with 4 headlights in a smart horizontal arrangement, more integrated fenders than its predecessor, as well as independent front-wheel suspension.

[2] This was the first medium-size truck to be able to carry 2 tons, and featured the same 85 PS (63 kW) 1,883 cc four-cylinder H engine as the 31-series Cedric.

Early catalogs also listed a double cab and a station wagon version, but it is doubtful that these were ever produced.

This interesting hybrid combined the 680-series heavy truck chassis, with its 125 PS (92 kW) 4-litre, six-cylinder P engine, with the Junior's bodywork.

This was slightly altered to accommodate the considerably taller engine, with higher fenders and an insert in the grille underneath the headlamps.

After 1964, the upper part was chromed and the lower section was painted in body colour.

[10] While considerably more modern than the 41-series, sales were unsatisfactory and Nissan soon cancelled exports outside of Asia.

[11] Sales in this segment slowed considerably as the eighties approached, as those of cabover trucks increased, and in 1982 the Junior was cancelled without a successor.