Each Friday on the Jeep_® Blog, we explore the Jeep brand’s iconic heritage by highlighting a different historical vehicle. This week’s vehicle is the 1951 Jeep Willys CJ-4M.

Have you ever seen a 1951 Jeep_® Willys CJ-4M? Heck, are you aware of its existence? The CJ series featured the CJ-2A, CJ-3B, and then the CJ-5 in 1955. As a result, many enthusiasts have often wondered what happened to the CJ-4. It’s a relatively obscure vehicle with little information and history, but it did, in fact, exist – as the prototype shown in these photos.

The CJ-4M, also known as the M-38E1, was a transitional vehicle, a variant of the CJ-3A with a taller cowl and rounded hood. The new features cleared space to fit the new F4-134 “Hurricane” engine under the hood. However, despite the apparent quality of the build, it only existed as prototype. The historical purpose of the CJ-4M, then, became to link the CJ-3A to the next military-specific model, the new Jeep Willys MD.

The U.S. Army eventually purchased approximately 82,000 Jeep Willys MD vehicles. The MD was a new, more powerful vehicle and ended up adopting the rounded hood, tall cowl, and nose of the CJ-4M. Mechanically, however, it was much different. Keep following the Jeep Blog for Heritage Fridays as we dig into the Jeep brand’s iconic history, including more about the MD.