M151A1, Truck, Utility, ¼ Ton (MUTT)

M151A1, Truck, Utility, ¼ Ton (MUTT). . , In 1951, Ford Motor Company won a contract to develop a new ¼ ton vehicle using the most modern automotive equipment of the time. The Army wanted to give the new vehicle a 'clean sheet' development, and by 1959 the design had matured enough to begin production as a replacement for the M38A1. Though the M151 Military Utility Tactical Truck (MUTT) looked similar to the old Jeeps, there were a number of differences under the frame. The new vehicle employed a 'unibody' design that allowed for more interior space and a lower silhouette than its predecessors. It also had an independent suspension for better rough terrain operations and a four speed transmission instead of the older three speed type. The M151A1 had a stronger rear suspension to increase load weight.

Production of the M151A1 was started in December 1963 by Willys Motors (Kaiser Jeep), who at that time held the production contract. Ford would regain the production contract in 1964 and produce the M151A1 until 1969, when continuing problems with its rear suspension brought about the development of the the M151A2. The 151A1's independent "A" Frame suspension was replaced with a semi-trailing arm suspension.

In 1971, AM General won production rights for the M151A2 and maintained it until the last order in 1988. While the M151 was replaced by the M998 HMMWV starting in the mid 1980s, the MUTT lasted longer in service than any of its predecessors.