September, 1970 marked the introduction of the first automatic transmission designed specifically for single-drive axle trucks and buses in the 10, 000 to 36, 000 pound GVW class. This new product is designated the AT-540 four speed, fully automatic transmission. After the background on the development of the AT-540 is presented, the basic design features and general applications are defined. The considerations of the vocations in which it will be applied are then discussed as related specifically to utility trucks. This includes power takeoff requirements, vehicle performance, and installation. Verification of the compatibility of the AT-540 transmission is presented with specific reference to the test program conducted, pilot vehicle operation, and production testing. The AT-540 has proven itself to be a durable, worthwhile component of vehicles for the utility industry.