The First AWD American Crossover Borrowed Tech From A 1966 British Exotic
One of the most important technologies in the modern crossover may owe its existence to a tractor company. Not metaphorically. An actual tractor company. Long before AWD became nearly standard equipment on family vehicles, British tractor magnate Harry Ferguson was trying to make four-wheel drive behave properly in a passenger car. The technology debuted in an exotic British GT, then crossed the Atlantic and wound up underneath a lifted American station wagon. Here’s the full story.
America Took A Surprisingly Long Time To Offer 4WD From The Factory
Today, 63% of new U.S. light-duty vehicles are built with AWD or 4WD. Things weren’t always this way, but not because the technology didn’t exist. Ferdinand Porsche used four electric hub motors to build what Porsche calls the world’s first AWD passenger car in 1900. Inventors in Wisconsin were experimenting with four-wheel-drive trucks by 1906 and established the Four Wheel Drive Company, which built 14,473 heavy-duty trucks for the U.S. government during WWI. By the 1930s, companies such as Marmon-Herrington were offering AWD conversion kits for production trucks. But roadgoing AWD still hadn’t become a Detroit passenger-car priority.
When the U.S. entered WWII, the government again needed rugged 4WD trucks. Dodge built hundreds of thousands of WC-series 4×4 and 6×6 trucks. After the war, Dodge prototyped a civilian version in 1945 and introduced the Power Wagon for the 1946 model year, bringing factory-built 4WD to civilian buyers.
The Power Wagon was far from the top-trim desert-running TRX that became Ram’s flagship off-roader decades later. Its L-head I6 made just 94 horsepower and 185 lb-ft of torque. It had a four-speed manual and a transfer case with a low range. The Power Wagon had a 126-inch wheelbase and carried a 3,000-pound payload. Buyers of the $1,627 vehicle could opt for a PTO or even a 7,500-pound winch. By modern standards, the Power Wagon was as much a piece of agricultural or work equipment as a pickup truck. It’s indicative of 4WD’s place in the late-1940s auto market.
The 1980 AMC Eagle Invented The Crossover Decades Early
Fast-forward to 1972, and American Motors Corporation was prototyping an all-new vehicle segment: a passenger car with 4WD. In hindsight, this makes sense for the company that built both muscle cars and Jeep. But it took the automaker eight years to fine-tune the design. AMC introduced the Eagle for 1980.
Buyers could option the 1980 Eagle as a sedan, coupe, or wagon. The wagon is by far the body style most associated with this model, as it was a pioneer of the modern crossover format. The Eagle essentially shared a unibody design with the Concord car, though it sat about three inches higher. It featured 15-inch rims with prominent fender flares. AMC advertised “automatic four-wheel drive,” offering genuinely innovative bad-weather traction. There was no way to shift the original 1980 system into 2WD mode. But that wasn’t the only major difference between the Eagle and the 4WD Jeeps AMC was building.
Instead of a solid front axle, the Eagle featured an innovative independent front suspension setup. In 1980, the only available engine was AMC’s 258-cubic-inch inline-six, which the automaker paired with a three-speed automatic TorqueFlite it sourced from Chrysler.
The Eagle was a success. In 1980, AMC built 9,956 four-door sedans, 10,616 two-door cars, and 25,807 wagons, or 45,379 vehicles in total. And honestly, this isn’t a shock. The Eagle offered a comfortable and capable package that had literally no competition. But today’s market, dominated by AWD crossovers, proves that moving four-wheel-drive technology from essentially agricultural and off-road vehicles into the passenger-car segment was a very smart play. Ironically, a tractor manufacturer was instrumental in the development of the Eagle. A British tractor magnate, to be exact.
The Eagle’s AWD Story Began With The 1966 Jensen FF
Though the Eagle was unprecedented in America, it wasn’t the first vehicle of its type. In 1966, Jensen Motors of England launched something unprecedented. The Jensen FF paired full-time four-wheel drive with a powerful grand-touring car and also featured Dunlop’s Maxaret anti-lock braking technology. What’s more, the Eagle and the Jensen FF were directly related.
Harry Ferguson, founder of the British tractor company, began working on four-wheel-drive passenger-car technology after WWII. Racing drivers Freddie Dixon and Tony Rolt had already been developing the tech for a performance vehicle. By 1950, Harry Ferguson Research Ltd. was pursuing a family car made safer by the technology. Ferguson himself defined the principles of the new system, and engineer Claude Hill came up with the controlled center-differential system that made full-time four-wheel-drive possible in the Jensen FF.
For its part, Jensen didn’t try to hide the Ferguson technology it had licensed. Harry Ferguson died in 1960, but HFR carried on, and the new Jensen’s “FF” nameplate stood for “Ferguson Formula.” HFR closed in 1971, and Tony Rolt formed FF Developments to carry the work forward. AMC later tapped that Ferguson/FFD engineering lineage while developing its “Automatic 4WD” passenger car. Ferguson historians list the AMC Eagle among vehicles tied to FF Developments proof-of-concept work or transfer-case components, though the exact terms of AMC’s arrangement are not public.
AMC Didn’t Copy The Jensen, It Evolved The Idea
The Jensen FF used a mechanical planetary center differential to allow front/rear speed differentiation and two mechanically controlled one-way clutches to manage torque. The Jensen Museum documents a rear-biased split of 37% to the front wheels and 63% to the rear.
Before Harry Ferguson Research closed, its engineers developed a newer Viscous Control system, or viscous coupling, as a cheaper and smoother route to volume production. FF Developments carried that idea forward, and the Eagle adopted the later Ferguson Formula concept with viscous control rather than simply copying the Jensen’s earlier mechanical arrangement.
These upgrades made the AMC Eagle drive much more like what modern buyers would call AWD than an old-school 4WD truck. Despite the “automatic 4WD” badges it wore, the original Eagle had a center system that could tolerate the speed differences between its front and rear axles on dry pavement, and it needed no low range or 2WD mode for normal road use. This is especially impressive engineering, because AMC may have been tempted to drop a Concord body on an old-school 4WD Jeep CJ powertrain and call it a day. Instead, AMC strove for genuine innovation and a better product. But the Eagle was still an endangered species from day one.
The AMC Eagle Went Extinct Before The Crossover Took Over
To its credit, AMC continued refining the Eagle throughout the 1980s. But in hindsight, it may have been AMC’s constant struggle to steal market share from the Detroit Three that drove it to build an AWD crossover decades ahead of its time. The automaker’s finances continued to degrade until shareholders approved Chrysler’s nearly $2 billion takeover in 1987. Chrysler kept the profitable Jeep 4×4 line, while the Eagle survived only into the 1988 model year.
Forty years after the Eagle’s debut, it looks as much like a prophecy as a car. The current market is absolutely dominated by car-based unibody crossovers. And 63% of new U.S. light-duty vehicles now come with AWD or 4WD. The Eagle’s extra ride height, comfortable handling, and all-weather traction would be right at home. In fact, Jeep now sells multiple unibody crossovers that have more in common with the 1980 Eagle than the 1980 CJ.
The strangest part of the Eagle story may be the distance the idea traveled: from Harry Ferguson’s dreams of a safer family car, through a rare British grand tourer, and finally into an AMC wagon from Kenosha. The Eagle lasted less than a decade. The formula behind it proved considerably harder to kill.
Sources: U.S. Environmental Protection Agency, Porsche, The Jensen Museum, The Ferguson Club
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