The story
The Hummer H1 is what happened when a defense contractor took a call from a movie star. Underneath, it's the Army's M998 HMMWV with gloss paint, carpet and a stereo. The frame, axles and brakes are shared with the military trucks, and so are the hood, tailgate and quarter panels. AM General built both versions on the same Mishawaka, Indiana, line from 1992 to 2006, 11,818 civilian trucks in all. It is 86.5 inches wide, seats four either side of a driveline tunnel the size of a footlocker, and can climb a 22-inch step. Nothing else on this site was built to that brief.
FROM JEEP'S DEFENSE ARM TO THE HUMVEE
AM General began as the General Products Division of Kaiser Jeep, the old Studebaker defense plant in South Bend. American Motors made it a subsidiary in 1971. In 1979 the Army published draft specifications for one truck to replace the M151 jeep, the M561 Gama Goat and the commercial-based CUCV pickups. It had to have a diesel, 16 inches of ground clearance and enough ability to climb a 60 percent grade. AM General developed its entry as a private venture and finished its first prototype in August 1980.
In July 1981 the Army ordered 11 prototypes each from AM General, Chrysler and Teledyne. They were tested at Aberdeen Proving Ground and Yuma. On March 22, 1983, AM General won the production contract for 55,000 HMMWVs. That same year LTV bought AM General: Renault had taken a large stake in AMC, and federal rules barred defense contractors owned by foreign governments, which included partly state-owned Renault. AM General had nicknamed its prototypes 'Hummer' and had the foresight to trademark it. Humvees were in service by 1985.
ARNOLD'S TRUCK
AM General had considered a civilian model since the late 1980s. Gulf War photographs and Arnold Schwarzenegger, who saw an Army convoy while filming Kindergarten Cop in Oregon, made the case. The civilian Hummer went on sale in 1992, and Schwarzenegger bought the first two. At first there were no dealers. You ordered from the factory and could collect the truck in Indiana. Flash Off-Road's year-by-year guide lists the 1992 truck with a mechanical 150-hp 6.2-liter GM diesel, a three-speed 3L80 automatic and a 65-mph top speed. It built 316 that year.
Then came constant change. Because of how the military contracts were written, AM General slipped fixes into production as soon as they were ready, not just at model-year changes. In 1994 the trucks got the 6.5 diesel and a four-speed 4L80-E. For 1995 a 5.7-liter gas V8 was offered to buyers who were wary of diesel, and it was dropped during 1996. In 1996 the 6.5 turbo diesel and a second fuel tank arrived, and by 1997 the turbo made 195 hp and 430 lb-ft.
HOW IT CLEARS 16 INCHES
The H1's clearance doesn't come from a lift. Each wheel has a geared hub, a portal reduction box with a 1.92:1 ratio in the 1999 brochure. It sits the axle shaft above the wheel center, so the halfshafts and differentials ride high in a channel down the middle of the truck. The disc brakes are inboard, next to the differentials, rather than in the wheels. Suspension is independent double A-arms with coil springs at every corner, and the track is 71.6 inches, wide enough to follow tank tracks. Mercedes used the same portal-axle trick decades later on the G 500 4×4².
Wading depth is 30 inches with a diesel, thanks to a high air intake and a radiator mounted high and sloped over the engine. The central tire inflation system lets the driver air the tires down or up from the cab, front and rear pairs together, and runflat inserts were optional. Torsen I differentials handled traction through 1998. In 1999 ABS arrived, along with Torsen II units and electronic TorqTrac4 traction control, and Eaton electric lockers followed from 2003.
GM, THE ALPHA AND THE END
In December 1999 General Motors bought the Hummer brand name and took over marketing. AM General kept building the truck, now called the H1, and also built GM's own H2 under contract. GM's smaller H3 came from a GM plant in Shreveport, Louisiana. In 2001 AM General began building the 6.5 diesels itself, having taken over GM's engine plant, and the 2004 'Optimizer' 6.5 made 205 hp. That set up the last and best H1: the Alpha, shown in Anaheim on October 27, 2004.
The Alpha used GM's 6.6-liter Duramax LLY, rated at 300 hp and 520 lb-ft, with an Allison five-speed automatic. To make room, AM General lifted the body 2 inches and redesigned the cooling. It also fitted helical-cut gears in the hubs, a stronger steering box and 51 gallons of fuel. There was no 2005 model year. Only 729 Alphas were built, at about $128,000 to $140,000 each. In May 2006 GM announced the end, with sales slow and new diesel emissions rules due for 2007, and production stopped in June. The Hummer brand itself closed in 2010. The name returned in 2020 on the electric GMC Hummer EV.
SIDEBAR · BODY STYLES
Wagon, open top, pickup, slant-back
AM General's VIN chart lists a two-door pickup, a four-door pickup, the station wagon and an open-body soft top, plus fleet and 'Recruit' versions. For 1995 it added an extended-cab two-door truck and an open top with full hard doors. The wagon got barn doors instead of a tailgate that year. The two-door short-cab pickup and the half-door open top were dropped for 1997, and the two- and four-door hardtops were dropped after 2001 except for fleet buyers.
In 2000 the factory offered a slant-back with the same body shape as the military Humvee. Flash Off-Road counts just 39 built, which makes it the rarest regular H1. By the end, individual buyers could only choose the soft-top open top or the wagon, and those were the only two bodies offered on the 2006 Alpha.
