DT12 Automated Manual Transmission

Driving the Evolution

Drive the next generation of technology with our 12-speed, direct- or over-drive automated manual transmission. It combines an automated clutch with a computer-controlled shift actuator to give you the power you need while optimizing fuel economy.

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Transmission automatically disengages when the vehicle is coasting to save fuel while sophisticated transmission electronics ensure safe operations in all driving conditions.

Skip Shift

The Transmission Control Module (TCM) sends electronic commands to “skip” unnecessary gears, helping increase acceleration to achieve cruising speed quickly and smoothly, and allowing the driver to accelerate in the appropriate “start gear” based on load and grade.

Powertrain Communication

A Common Powertrain Controller optimizes high-speed communication between the Motor Control Module and the Transmission Control Module, improving operational efficiency throughout the entire powertrain.

Active Driveline Protection

The Transmission Control Module (TCM) calculates the torque wind-up in the driveline and regulates with engine torque control for enhanced driving comfort and less driveline wear.

Direct Drive

A 12-speed, non-synchronized transmission with shorter gear steps. In top gear it operates as a direct drive, sending engine input directly to the main shaft, eliminating parasitic gear mesh losses.

Total Weight

The aluminum housing and single countershaft help save weight, allowing for even more payload efficiency.


Engineered for Economy

Your fleet’s profitability depends on boosting fuel economy and increasing durability. Our engineers have looked at every opportunity to reduce fuel consumption and increase efficiency. They’ve built sturdy components and designed the DT12’s operation to limit unnecessary wear and tear.

With more new drivers coming into the market, it’s critical to ensure your fuel economy goals are met, and your trucks continue to last for years to come. With our easy-to-operate AMT transmission, drivers reach their optimal performance sooner.

Truck Transmissions

Drive to Perform

How does the Detroit DT12 assist drivers?

  • A pneumatic actuator engages the clutch and shifts the transmission, allowing for faster and smoother gear-shifts compared to electronic actuation.
  • Several options of driving modes depending on terrain and specific applications, including:
    • Performance Mode to climb mountains
    • Eco Mode for efficient city driving
  • Creep Mode to improve low-speed maneuverability, making it ideal for backing up to a loading dock or in traffic.
  • A true two-pedal system and Shift Lever.
  • A pedal kick down feature gives the driver full throttle control to increase acceleration when passing or driving on uphill grades.
  • Advanced safety features like Auto Neutral where under certain conditions, the transmission electronically commands “neutral” gear.
  • Virtual Technician is a factory-installed onboard diagnostic system that puts you in control of your business 24/7 and takes the guesswork out of powertrain repair by helping you to manage your business more efficiently.

When combined with a specially designed driver interface with enhanced cruise control, drivers have plenty of ways to further improve their fuel efficiency.

At Your Service

Detroit transmissions are spec’d, sold and serviced by an unmatched network of knowledgeable sales people and expert factory-trained technicians at hundreds of Freightliner dealers throughout the United States and Canada.

Detroit offers outstanding parts availability and transmission owners also enjoy comprehensive warranty coverage — including fast, hassle-free processes — and expedited parts and service for critical downtime situations. Our transmissions come with a 5-year/750,000 mile standard warranty.

Detroit DT12 Transmission
Detroit DT12 Specifications
Speeds 12 forward / 4 reverse
Torque Ratings 1,250 - 2,050 lb./ft.
Gear Ratios /
Overall Ratio
Direct Drive: 14.93 - 1 / 14.93
Over Drive: 11.67 - 0.78 / 14.96
GCW Limits Direct Drive: 80,000 lbs.
Over Drive: 130,000 lbs.*
Dry Weight 518 - 639 lbs.
Oil Capacity 10.7 - 15.4 qts.
*With dual plate clutch. Application approval required.




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