Seal Design

Improved seal design for optimal leak protection.

Heavy Duty Yokes and Flanges

Added robustness to optimize drivetrain performance in down speeding applications.

Hypoid Design

Achieves maximum balance in fuel efficiency and durability.

Axle Lubrication Management (Optional)

Actively regulates oil level at the ring gear to reduce “churning” to drive additional fuel economy benefits.

Tandem Rear Axle

• New Axles Designed for Fuel Economy: To provide optimum efficiency and performance, the Detroit™ Powertrain includes an all-new axle specifically designed to integrate with the downsped DD13®, DD15® and DT12™, resulting in rock-solid reliability and durability.
• Faster 6x4 Axle Ratios: The 6x4 configuration is available for applications requiring 4-wheel drive and superior traction. A variety of faster axle ratios are available, ranging from 2.41 to 2.28.
• Faster 6x2 Axle Ratios: The 6x2 configuration boasts a 2.28 ratio, allowing the DD15 to turn lower RPMs with the truck cruising at the same speed. It pairs perfectly with the low RPM torque curve and direct drive transmission. This means it can cruise in top gear longer, for better fuel efficiency.
• Lighter 6x2 Axle: The 6x2 axle configuration incorporates a non-driven tag axle on the tandem, reducing total weight (by 380 lbs) and the number of moving parts, delivering better fuel economy.
• New Optional Axle Lubrication Management (ALM): The tandem rear axles feature an optional axle lubrication management (ALM) system that actively regulates the oil level at the ring gear and friction-loss optimized pinion bearings to reduce friction and parasitic loss, extending gear life and further improving fuel efficiency.

Steer Axle

• Numerous Steer Axle Advantages: Detroit™ steer axles offer rugged strength in a lightweight package, and integrate optimally with the other components. They are designed for the life of the axle, with multiple ratings available for tailored weight distribution.
• Superior Maneuverability: The Detroit™ Powertrain's state-of-the-art steer axles provide a 55-degree wheel cut for remarkably nimble maneuvering. 
• Needle Bearings Improve Durability: With needle bearings instead of bushings, they won't damage the king pins, and offer increased durability.

Engine

Transmission

• Integrated Communications Benefits: The DT12™ transmission links engine to axles, and communicates with the DD13® and DD15® on an integrated electronics network to share damage-reducing information such as clutch overloading and driveline protection.
• Super-Finished Gears: Tightly-spaced 12-speed gearing, now with "super-finished" gears in the new DT12™ available for the new Cascadia and Western Star® 5700XE, improves low-speed maneuverability, making the Detroit™ Powertrain not only strong and efficient, but also smooth and safe to operate as well.
• Intelligent Powertrain Management (IPM): The DT12™ uses information from a topographical map to manipulate both engine and transmission functions, taking advantage of the truck's surroundings. IPM4 refines the parameters of this technology, making the truck even more capable of utilizing its surroundings efficiently.
• Transmission Benefits: The DT12's direct drive and over drive gearing, along with eCoast, are integrated with the downsped engine — which now idles at a lower 500RPM when off-throttle — for optimized fuel economy.

Aftertreatment