CarBrandLogos archive · Jeep · 1941

JeepWillys MB

Designed in a fortnight, built by the hundreds of thousands, copied ever since.

Photo: BrokenSphere · CC BY 3.0

The story

A defining chapter in Jeep history.

Explore the ideas, engineering and context that shaped the Jeep Willys MB, then continue into its specifications and place in the marque's lineage.

1917 - Indian Motorcycle and M1914 Colt Machine Gun

Origins

In the summer of 1940 the US Army issued a specification for a light reconnaissance car and gave manufacturers seven weeks to respond, with a working prototype required in 49 days and a weight limit almost nobody thought achievable. Only American Bantam, a small and nearly bankrupt firm in Butler, Pennsylvania, took it seriously. Its chief engineer Harold Crist and a freelance draughtsman, Karl Probst, laid the vehicle out in a matter of days, and Bantam delivered on time.

1917 - Indian Motorcycle and M1914 Colt Machine Gun · Unknown authorUnknown author · Public domain

Design and engineering

The Army liked the design and doubted Bantam could build it in quantity, so it handed the drawings to Willys-Overland and Ford. Willys contributed what proved to be the decisive element: the 134-cubic-inch L134 "Go Devil" four, which had considerably more torque than Bantam's engine and was reliable enough for sustained abuse. Ford contributed manufacturing scale and the flat stamped grille that everyone now takes as the definitive face. The standardised vehicle entered production as the Willys MB and, from Ford's lines, the effectively identical GPW.

'46 Jeep CJ · Bull-Doser · Public domain

In production

What emerged was a quarter-ton 4x4 with a three-speed gearbox and a two-range transfer case, folding windscreen, no doors, and a body simple enough to be repaired in a field with basic tools. It was light enough that a few soldiers could manhandle it out of a ditch. Well over half a million were built during the war, and they did far more than reconnaissance: ambulance, gun tractor, signals platform, staff car, generator, and improvised everything else. War correspondents wrote about it the way they wrote about the men, and Eisenhower listed it among the handful of tools that won the war.

100th 442nd Veterans Association · mark6mauno · CC BY 2.0

Legacy

The name has never been settled. Ford's "GP" designation, an existing piece of Army slang for an untested recruit or vehicle, and a Popeye character called Eugene the Jeep have all been offered, and none of them is conclusively supported.

Chapter 5

Its consequences were much larger than its war. Willys registered Jeep as a trademark and put the CJ into civilian production in 1945, creating both a company and a vehicle category. Britain's answer, the Land Rover of 1948, was drawn up by a man who had been running a war-surplus Jeep on his own farm. Toyota, Nissan, Mitsubishi and later Suzuki all built vehicles that started from the same premise. Eighty years on, the Wrangler still has a seven-slot grille, a flat windscreen and removable doors because of a design sketched in a fortnight in 1940.

At a glance

The facts that define it.

Engine

134 cuin inline 4 Willys L134 "Go Devil"

Designer

Multiple parties and persons:

Technical specification

The Willys MB, in detail.

Engine: 134 cuin inline 4 Willys L134 "Go Devil"
Transmission: 3-speed × 2-range transfer case
Designer: Multiple parties and persons: ; American Bantam Co. ; Harold Crist et al.refn; group=nb ; Other core Bantam engineers were Ralph Turner, Frank McMillan, and Chet Hemphling. ; Karl Probst (subcontractor) ; Ford Motor Co.
Manufacturer: Willys; Willys-Overland (MB) ; Ford Motor Company; Ford (GPW)

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