War Rigs - Jeep Autopsy: U.S. Military

There are far too many other variations of the M-classes to detail here-everything from gun carriers and ambulances to hybrid 3/4-ton 6x6x6s-but they included the M-170, an ambulance version of the CJ-6, from 1953 until around 1967. The M-606 represented the military CJ-3B, while the M-606A2 and A3 were CJ-5 versions. Platform-style military rigs were the XM443-E1, called the "big brother" of the M-274 Mechanical Mule, which could carry six or convert for cargo.

For the mechanical sections of the military vehicles, we'll focus on the MA, MB, M38, M38A1, and M-715.

The MA used the Go-Devil, as did the MB and M38. The M38A1 sported a 72hp,F-head, 134ci Hurricane that made 114 lb-ft of torque, while the M-715 ran a 132hp, one-barrel, Tornado, 230ci six-cylinder with 7.5:1 compression and 198 lb-ft of torque.

All manuals: The MA and MB had a three-speed Warner T-84J, and the M38 and M38A1 had a three-speed T-90, while theM-715 had a four-speed Warner T-98.

The MA and MB featured full-floaters front and rear: a Model 25 and Model 23-2, respectively; both had 4.88:1 axle ratios. The M38 and M38A1 had a full-floating Model 25 front axle and a semifloating Spicer 44 rearend with 5.38s, while the brawny M-715 scored the full-float Dana 60 front and Dana 70 rear with 5.87s. Everyone got leaf springs.

Everything but the M-715 used a Spicer Model 18 with 2.43 Low range, although all the early military flatties had a 1.97 Low. The M-715 had a divorced NP200 with 1.96 Low.

One of the easiest ways to tell the difference between an MB and a GPW is to look at the front crossmember. Tubular equals Willys.

The official name of the Mule was Carrier, Light Weapons Infantry, 1/4-ton, 4x4 M274. It needed two birth certificates to fit all that.