They are famous for the use on the Red Ball Express from Normandy to the front, but were also used in the China Burma India Theater.

[1] All models had a ladder frame with two axles on semi elliptical leaf springs.

The front axle was an I-beam, the rear was a double reduction full floating type.

M425s had 9.00x20 size tires, while M426s had larger 11.00x20s with stronger springs and a slightly longer 10 metres (32.81 ft) wheelbase.

Except for the difference in the size of the tires, and some minor details, all types are mechanically identical.