From Zero to Hero - Jeep M715

Space: The final frontier... If you can't recite the rest of the words to that legendary voiceover from a certain 1960s television series, you probably know someone who can. Star Trek: The Original Series debuted on NBC in 1966. Then the ill-fated space drama was taken off the air in 1969.'' Though launched at a time when Americans should've wanted to gaze out into the night sky for a little relief from the very real happenings on Earth, Star Trek was a Nielsen ratings black hole. Even the star of the show (and the voice of the aforementioned famous opening utterance), William Shatner, has said he thought the famous "five-year mission" would last only one season. Ironically, it tanked even as America gazed proudly upward at the success of the Apollo space program.

But then something funny happened to Star Trek on the way back to space dock. In syndication, the show achieved a cult-like popularity. There were conventions, lunchboxes, major motion pictures, spin-offs... suddenly Star Trek was a wildly popular franchise, and it remains relevant 42 years after the original show was taken off the air. A resounding success reaped from the seeds of failure. Was it simply an idea that was ahead of its time?

Right about the time that Star Trek's orbit was decaying, Kaiser Jeep was working on a successful failure of its own, the M715, meant to upgrade military hauling technology, if not boost it to the stars.

For almost 20 years following World War II and through the Korean War, U.S. troops had come to rely on the Dodge M37 for their light hauling tasks. The M37 first rolled off the line in 1951. It was a dependable warhorse, but hardly a major departure from the WC series trucks used in World War II or civilian WDX Power Wagons. The M37 was a ¾-ton 4x4 truck powered by the same ancient 230-cu.in. L-head straight-six engine that powered the WC, as well as many other Chrysler products. Standard-issue stuff also included a four-speed manual transmission, a two-speed transfer case, drum brakes and leaf springs fore and aft. Again, nothing exotic to be found here, but the M37's ruggedness is still legendary--even though engine failures weren't all that uncommon as the trucks aged, probably as a result of the almost continuous high RPM needed to keep the truck moving forward with short gears and little power.

By the late 1960s, though, the M37 was ripe for an honorable discharge and the military hoped to replace it with a vehicle that offered greater mobility and a larger load capacity. The result was actually two vehicles: the strange-but-true mid-engine M561 "Gamma Goat" and the Kaiser Jeep M715. The M561 was a high-mobility, amphibious 1.5-ton 6x6 truck powered by a Detroit Diesel engine. The KJ M715, however, was more of a direct replacement for the M37.

The plan was to use a civilian truck, or at least base the new military truck on civilian truck components in order to keep costs down; in later years, 11/4-ton military trucks would be virtually identical to their civilian counterparts. Unfortunately, for all its good intentions, circumstances conspired against the M715: Upon its introduction, it would have an immediate baptism by fire in Vietnam and in that crucible, it fell short of living up to the Jeep legend.

Based around a Jeep Gladiator light truck, the M715 rode on a Dana 60 front axle and Dana 70 rear axle coupled to a divorced NP200 transfer case (meaning that the transfer case was driven by a shaft rather than being connected directly to the transmission). The transmission was the heavy-duty Borg-Warner T98 with a compound low gear; the truck's final drive gear ratio was a goat-trail-climbing 5.87:1.

The M715's Achilles heel was its Tornado 230 overhead-cam straight-six powertrain. The Tornado was an idea far ahead of its time when development began in 1960, but by the time Kaiser Jeep installed it in the first M715s in 1967, it was an engine whose time had passed. The Tornado's reputation for dependability is still debated among enthusiasts today, but with 140hp and 210-lbs.ft. of torque, there's little doubt that the Tornado was overwhelmed by this 5,180-pound 4x4 military truck, even with ultra-deep gears.

The Tornado 230 was the brainchild of Willys engineer A.C. Sampietro, who was assigned the task of designing a new engine for the all-new 1962 Jeep Wagoneer. The lower end was based on the "Super Hurricane" 226-cu.in. straight-six with a hardened crankshaft. Its under-square 3.44x4.37 bore and stroke was suited for developing grunt just above idle, while the OHC head with its cross-flow design and hemispherical combustion chambers was ideal for building power through free breathing.

It was a good plan, but the early civilian versions suffered from oil leaks and oil consumption. There were also cam and cam bearing failures--likely due to low oil levels caused by the leaks. The problems were ironed out, but not before the engine had earned a reputation for being unreliable. It was replaced in the Wagoneer during 1965 with a 232-cu.in. pushrod straight-six engine that Kaiser Jeep purchased from AMC.

The Hurricane 230 continued as a production engine in Argentina, used in cars built by Kaiser's South American subsidiary, Industrias Kaiser Argentina. The Hurricane that appeared in the M715 was a vastly improved engine from the one that powered the earliest Jeep civilian trucks, but it still suffered reliability problems.

As a result of engine-related woes, build-quality issues and a general opinion that the truck was underpowered, the M715's service only lasted about nine years following its 1967 introduction. Its replacement, the Dodge 11/4-ton M880--a conventional fleetside full-size Dodge pickup-- arrived in 1976. It's been reported that Kaiser Jeep built 30,400 M715s for the military from 1967-'69.

It isn't known how many were destroyed--or simply left behind--during the Vietnam War. Many M715s remained at bases in the U.S., later to be auctioned off at government sales. Others were sold or simply given to other government agencies. Repurposed M715s were commonly used by fire departments as brush-fire fighters, outfitted with a water tank and pump in the bed, as our crisp-looking feature truck demonstrates.

These trucks are neither difficult nor expensive to obtain or restore. The grille and hood are Jeep Gladiator components, while doors and fenders from Jeep full-size pickups can be adapted to work. The M715's front fenders are standard Jeep items, but the openings are huge and circular to accommodate the military truck's 34-inch-tall 9x16 tires. The cab is basically a Gladiator or J-10 unit, but with a flat windshield and a canvas top, so a direct interchange between an M715 and a civilian Jeep pickup, while possible, isn't as straightforward as a casual observer would think.

The M715 standard pickup bed is very simply shaped, and repair panels aren't difficult to fabricate. These beds are fairly plentiful on the used market, as well. It's worth noting, too, that there were other versions of the M715 built, including an ambulance-bodied truck called the M725 and a utility-bodied truck called the M726.

What're these trucks worth? Fortunately for those who appreciate them, military trucks aren't muscle cars when it comes to value. (Perhaps because so many muscle car enthusiasts are ex-vets who prefer to own the vehicle they aspired to in their youths, not the vehicle Uncle Sam insisted that they drive for four or more years!) According to popular pricing guides, the low end is about $1,000, while the high end is $11,000. Poking around on the web and in back issues of Hemmings Motor News recently revealed many nice, though not perfect, examples for sale in the $5,000 to $10,000 range.

Trucks that have had engine swaps are common--predictably, the small-block Chevrolet is a popular transplant. AMC V-8s and, of course, GM as well as Cummins diesels are also a hot swap. Because the transmission, axles and transfer case are all sourced from separate vendors and were used in other 4x4s, rebuilding or replacing them is not difficult.

Driving these trucks today can be an eye- (and ear-) opening experience. Without any sound deadening material and with that old Jeep build quality, they are noisy, to say the least. Though they're reputed to have a top speed of 60 MPH, driving an M715 at that speed on bias-ply tires with manual steering (with which they were all equipped) would take the courage of a Medal of Honor winner.

So, all of that said, you'd figure that these trucks, given their generally lousy reputation, would be shunned by anyone other than scrap-metal dealers today. Wrong. When it comes to a cult following, James T. Kirk and his cohorts have nothing on the M715. Recreational off-roaders love these trucks, as do military vehicle enthusiasts. There are several great websites devoted to the M715, the most widely cited of which is www.m715zone.com, and they are a favorite feature subject of the popular off-road truck magazines.

But wait, there's more: The M715 has even spawned overseas imitators. Korean automaker KIA manufactures a diesel-powered M715 look-alike for the Korean military, reportedly licensed by the U.S. government. The truck is called KM 450 and bears a striking resemblance to the M715, the primary differences being the shape of the wheel wells and the grille. For power, it relies on a 139hp 3.9-liter four-cylinder diesel connected to a five-speed transmission.

Nor has the Chrysler Corporation completely forsaken the M715. Last year, Jeep and Mopar Parts showed off a wild off-road pickup concept vehicle based on a Jeep Wrangler, sporting an M715-inspired front-end treatment. It was dubbed the Jeep Nukizer (Get it? "New Kaiser") M715, and Jeep enthusiasts went nuts over it.

Hmm... a '60s flop that's now a resounding success? Sound familiar? Better beam an M715 into your garage before their popularity hits the outer limits.