The MT 40B features a Scania DSI 14, turbocharged V-8 diesel engine with increased power to 450 horsepower (333 kW), making the MT 40B a powerful 40-ton (36 t) truck in its class. The new engine has an electronic fuel-injection system, improved cold starting performance, and is digitally linked to the transmission.

The new ZF 6 WG 310 transmission with EST 37 powershift automotive style has six forward and three reverse gears, and automatic converter lockup in all gears.

The MT40B has a ribless style body design with a scow end and conical shape toward the rear to reduce material sticking and provide additional strength. The shorter, curved front wall reduces overspilling during loading. The body tilting system can automatically sense unequal weight distribution and stop the unloading process. The body is constructed of hardox 400 hardened steel plates in the bottom, front, and sides. The MT 40B has a 29 cubic yard (22 cu m) heaped capacity.

For improved performance, the oscillation ring has been redesigned as a separate and sealed unit with an increased diameter for improved lubrication to prevent dirt penetration. The ring is now attached to the front frame and to the articulated steering hinge. The rear frame has also been improved for greater fatigue strength and durability.