M422 Mighty Mite

M422 Mighty Mite
Initial series M422, with 65-inch wheelbase
Type	1⁄4 ton (227kg) 4x4 utility truck
Place of origin	United States
Production history
Manufacturer	American Motors Corporation
Produced	1959 - 1962
No. built	1,250 (+ 2,672 M422A1)
Variants	M422A1
Specifications
Weight	1,700 lb (770 kg) empty
Length	107 in (2.72 m)
Width	61 in (1.55 m)
Height	59 in (1.50 m)
Engine	107.8 cu in (1.8 L) 55 hp (41 kW)
Suspension	independent with leaf springs
Operational range	225 mi (362.1 km)
Speed	62 mph (100 km/h)

The M422 'Mighty Mite' is a lightweight ¼-ton 4x4 tactical truck, suitable for airlifting and manhandling. From 1959-1962, the Mighty Mite was built by American Motors for the United States Marine Corps.

The vehicle was originally prototyped starting in 1946, making it the first all-new Jeep to be designed for the U.S. military after World War II, and further developed during the 1950s by a team including four of the original Bantam engineers. A design called MARCO MM-100 by the Mid-American Research Corporation used a Porsche air-cooled engine and independent suspension. A unique feature was the absence of a conventional exhaust system. The prototype did not have a muffler or pipe rather the exhaust was routed through the frame. This proved to be an inferior design because the condensation and acidic fumes caused premature frame failure. A competing prototype by Willys, the 1953 Bobcat or "Aero Jeep", which would share as many parts as possible with the M38 and M38A1 to save costs, was rejected in favor of the more advanced M422.

Although the vehicle was to be used only by the U.S. Marine Corps, and it was therefore clear from the beginning that production numbers would remain limited, the vehicle was extensively engineered and incorporated many innovations.

To keep the weight down, the M422 became the first U.S. jeep to be fitted with an aluminum body. At 1,700 pounds (771 kg), it is the lightest of the American military trucks to date. Also, this was the first U.S. small military vehicle designed with independent suspension all around (front: leading arms/trailing arms rear), sprung by ¼-elliptical leaf springs. Among the M422's many other unique features were front and rear limited-slip differentials, inboard differential mounted drum brakes, center-point steering, and the aluminum "AMC AV-108-4" V4 engine developed by American Motors. The air-cooled 107.8 cu in (1.8 L) developed 52 bhp (39 kW) and 90 lb·ft (122 N·m) of torque, which propelled it to a top speed of 65 miles per hour (108 km/h), with a 55-mile-per-hour (89 km/h) military rating. As with the M151, the transfer case only engages/disengages the front wheel drive and is part of the transmission. The full synchronization meant it could be shifted from 2-wheel drive to 4-wheel drive on the fly.