AMC Eagle: American 4x4 Pioneer

police EagleThough Subaru claims to have the “first sport utility wagon,” the AMC Eagle pre-dated it by 17 years, using the revolutionary New Process Gear NP119 transfer case that transferred power to the wheels with the most traction via a 42-disc viscous coupling transfer case. This “Quadra-Trac” full time four wheel drive system was co-developed by AMC/Jeep and New Process Gear, using technology from (according to contemporary reports) FF Developments, perhaps better known for its work on the Jensen FF.

Power went through the rear driveshaft and was sent to the left using a Morse Hy-Vo chain to the front of the car. Differential action was aided by a viscous coupling, which also limited slip; the system was sensitive to velocity. The silicone-based fluid in the coupling had high shear and heat resistance, keeping its viscosity through a wide temperature range (starting at 40°F below zero and going over 400°F). A byproduct of the system was some anti-skid protection, brought about by the way it worked to equalize driveshaft speeds — whether or not the car was moving under power.

Bob Sheaves wrote: The NPG119 was indeed the replacement for the Warner system originally used on the Eagle. The NPG119 was created to solve issues that cropped up on the NPG203, the first of the FF-derived full time 4x4 transfer cases, and the NPG119 was the first modern style (low drag, low fuel milage penalty) transfer case designs.

The big advance of the NPG119 was the “silly putty” fluid-shear force, Dow Corning silicone fluid used as a limited slip differential within the transfer case. The NPG203 (and the later 242) used a conventional differential that had a manual locking feature to control the speed difference between the front and rear outputs of the transfer case.

Eagle diagram

The AMC Eagle had its roots in the 1978 launch of the AMC Concord, an upmarket version of the compact AMC Hornet. Concord, essentially a stretched Gremlin, sold as a sedan, hatch, and wagon, with a four-cylinder, 232 and 258 six, and 304 V8 available. The car was an immediate hit, with 121,293 cars sold in its first year, easily beating every other AMC car — combined.

AMC chose a completely new name for the 4x4 version of the Concord; thus, the AMC Eagle was born. It had minor sheet metal and trim changes, largely due to its higher stance, standard 15-inch wheels were standard (Concord used 14s), and three inches more ground clearance. The car was available as a two or four door sedan, and as a four door wagon. Like Concord, it used recirculating ball steering rather than the trendy rack and pinion, and to the end of its life would keep front disc brakes with rear drums.


The AMC Eagle came with one powertrain: the 114 hp/210 lb-ft straight-six (258 cid) with a Chrysler 998 TorqueFlite transmission (called Torque Command by AMC) controlled by a T-handle floor shifter. The 4.2 liter engine, an AMC mainstay for many years and father of the 4.0, benefitted from a Carter two-barrel carburetor, a good investment versus the single-barrel Holleys used by Chrysler for too many years.

1980 AMC Eagle

The standard final drive ratio was 3.08:1, with an optional 3.54:1 ratio that was mandatory with the high altitude and medium trailer towing packages. Radials were standard, P195/75R15 sized, along with power steering and brakes.

It used an independent front suspension rather than a traditional 4x4 live front axle, which helped cornering and tire wear. It was not the first 4x4 car to use an independent front suspension, but it was one of the first. Since the car was unit-body, not body-on-frame, the differential and axle tube were attached to the engine rather than the body. The basic design of the front suspension was similar to Concord other than concessions made to four wheel drive; though higher spring rates were used.

AMC Eagle 4x4

Buyers could get an optional heavy duty suspension, with a heavier front roll bar (going from 0.94” to 1.06” diameter), a 0.63” rear roll bar, different front shocks, and thicker rear leaves for the leaf-spring rear suspension. A Delco (GM) automatic load levelling system was also optional, using air shcoks and an electronic height sensor. The transfer case and front end had skid plates.

1980 AMC Eagle
Ground clearance7.0”  Horsepower114 hp @ 3,200
Length, wheelbase186” , 109.3”Torque210 @ 1,800
Width71.9”Bore x stroke3.75 x 3.90
Height55.0 - 55.8”Compression8.3:1
Fuel tank22 gallonsIgnitionElectronic
Cargo volume11.4 (sedan)
57.0 (wagon)
Weight3,306 lb (2 door)
3,361 (4 door)
3,407 (wagon)
Legroom, front/rear104 / 92 Head room, f/r97 / 96
Hiproom138/136 Cargo liftover78”

For 1980, trim lines were standard, Limited, and Sport; Limited added leather or fabric seats, thicker carpeting, AM radio, woodgrain tilt-steering wheel, power locks, locking storage (wagon), rear passenger straps, lighting, visibility, and convenience groups, protection group, front parcel shelf, cloth sun visors, and various trim pieces. Sport (two door and wagon only) added fabric seats, leather-wrapped sport steering wheel, high-beam halogens, fog lights, dual remote mirrors, black sidewall radials, opera window insert, blackout exterior and interior treatments, and pinstripe delete.

Interesting options included Ziebart factory rustproofing, a CB or cassette stereo (four speakers), tachometer, rear defogger, wagon rear wiper/washer, moon roof, cruise, tilt wheel, and fog lamps. The light duty trailer towing package was only good for 2,000 pound trailers, and included a bumper-mounted hitch, harness, and wiring kit; the medium duty package was for trailers up to 3,500 lb and included an equalizing hitch, harness, wiring kit, auxiliary transmission fluid cooler, and 3.54 axle ratio, and required the optional heavier duty shocks and load-levelling air shocks.

plaid seats

1981: Eagle SX/4 and Kammback, four cylinders

In 1979, AMC had replaced its Gremlin with the AMC Spirit, a similar car but with more conventional styling; it had numerous “normally optional” standard features. With just 22,104 Gremlins sold in 1978, it seemed a logical move; and it worked out well, with 52,714 Spirits sold in their first year, more than doubling Gremlin (in 1979, AMC also sold 102,853 Concords). Spirit sales rose to 55,392 in 1980, the Eagle’s first year, while Concord sales fell to 70,336 — but Eagle sales added 34,041 to that total, and one could argue that Eagle merely diverted Concord sales.

amc eagle sx/4

For 1981, AMC launched the Eagle SX/4 and Kammback; these were both 4x4 versions of the AMC Spirit. The Spirit itself was a revised AMC Gremlin with larger rear quarter windows. SX/4, being smaller than the Concord-based Eagles, weighed in at 3,033 lb — around 230 lb less — and got better mileage with the automatic. The Spirit-based Eagles were “series 50,” and their high trim version was called DL; the Concord-based Eagles were “series 30,” and their high trim version remained Limited. (Sport was also optional for both.)

A four cylinder engine purchased from GM was the base engine across the board; the big four displaced 151 cid (2.5 liters), and bore no resemblance to the later AMC 2.5 four-cylinder. With a two barrel GM/Rochester carburetor, it was good for 82 hp and 125 lb-ft of torque. Regardless of engine, buyers could get a four speed manual, five speed manual, or automatic (four-cylinder automatic wasn’t available on the larger Eagles).

For 1982, a new five-speed manual was available, supplementing the four-speed.

EPA City/HighwayFour cylinderSix cylinder
Automatic, exc. SX/4Not available20/28
Automatic, SX/420/26

Griffith made a limited number of Eagle and Concord "Sundancer" convertibles, with fixed targa band, removable T-tops, and droppable canvas rear top.

amc eagle SX/4 Sport 258

For 1982, the year Renault bought 49% of AMC’s stock, Eagles could be switched from four wheel drive to rear wheel drive with “Select Drive.” This was a less sophisticated system, but less expensive as well; drivers had to stop the car to shift, but did not have to leave the car to use the “finger tip control” lever. It retained the controlled-slip differential, and allowed for somewhat higher gas mileage in rear wheel drive mode.

One largely forgotten part of AMC history was the use of a computer for the electronic feedback carburetor which could provide mechanics with diagnostic information.

eagle interior

Gene and Gary Henderson raced an Eagle SX/4 (née Spirit) in the SCCA Pro Rally. Still, sales plummeted to just 37,797 cars. AMC has a whole sold fewer than 100,000 new cars in the United States, with a market share of 2%, echoed in Canada.

For 1983, AMC made a 2.73:1 ratio standard with the six cylinder and manual transmission (or six cylinder and automatic in high altitudes), and a 2.35:1 ratio with the six cylinder automatic. The standard ratio for four-cylinders was still 3.54. The six cylinder now used an electronic feedback carburetor with an oxygen sensor; AMC boosted compression to 9.2:1, and used a knock sensor to retard timing if fuel wasn’t up to the task. Eagle was the official car of the National Ski Patrol.

AMC Eagle

Slower selling Eagles were dropped — the Concord based two door and Limited four-door. Midyear, AMC’s new 2.5 liter engine, just one cubic inch smaller in displacement, replaced the 151; this was a strong engine that would be an AMC mainstay and eventually end up in the Dodge Dakota. Still, Eagles sold poorly, with 31,604 leaving the showrooms. That was still double the sales of Concord and over four times that of Spirit. Not surprisingly, at the end of the year, with the AMC-built Renault Alliance selling well, AMC dropped the Concord and Spirit. It also dropped the Eagle SX/4, which now accounted for only around 10% of Eagle production.

AMC Eagle without SX/4

For 1984, the only true AMC car was the Eagle, in four-door sedan and wagon bodystyles; the Jeep Cherokee (XJ) launched, quickly becoming one of the most popular sport utility vehicles of all time. AMC had a single model. At this point, the Renault Alliance and Alliance-based Encore hatchback were responsible for nearly all AMC car sales. Eagle went to a single production facility.

amc select driveEagle’s base engine was the AMC 2.5 four-cylinder, using a single barrel feedback carburetor. Total sales were 23,137. For 1985, buyers could shift into and out of 4x4 mode at will, without stopping the car; but they could not buy the four-cylinder engine (not that many had before). The atlernator went from 42 to 56 amps, and hoods swapped a “scoop effect” for their old hood ornaments. All cars got four-speaker radios. Still, sales fell to 15,362 for 1985, then down to 9,020 in 1986.

In 1987, Chrysler Corporation bought AMC, and renamed the carline to Eagle, creating the Eagle Premier and — yes — the Eagle Eagle. Available as just a wagon, the car still sported the 4.2 liter, 258 cid six cylinder, with a two barrel carburetor and five-speed, fully synchronized manual transmission with optional TorqueFlite automatic. The wagon weighed in a 3,425 pounds, close to its original weight. The last car was made in 1987. The car ended its life with a base price of just under $13,000.

The car was dropped, but, oddly, the name was taken on by AMC’s new owners, Chrysler Corporation (which had bought the company in 1987). The Renault Premier and 1988 Medallion were both rebadged as Eagles.

AMC history pageAMC Gremlin


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