Rock Products - The Leading Voice of the Aggregate Industries.

Mack Expands Heavy-Duty AMT Range with Two New Mack mDRIVE HD Models

48 MackMack Trucks announced two new versions of its Mack mDRIVE HD automated manual transmission (AMT). As the first truck manufacturer in North America to offer low reduction gear ratios in a proprietary automated manual transmission, the mDRIVE HD 13-speed and  mDRIVE HD 14-speed meet the needs of an even wider range of customer applications with the power and performance that only a fully integrated powertrain can offer. Mack made the announcement at the Work Truck Show in Indianapolis.

Available in direct or overdrive configurations, the new mDRIVE HD 13-speed offers a low reduction gear ratio designed for easier starting on steep grades or when the truck is under heavy load. The mDRIVE HD 14-speed, available only in an overdrive configuration, adds a second ultra-low-speed reduction gear designed for curb pouring applications or low-speed, heavy-haul maneuvering. Both transmissions offer up to four reverse gear ratios.

“We launched the original mDRIVE HD in response to customers looking for an AMT capable of withstanding tough vocational applications,” said John Walsh, Mack vice president of marketing. “Now, with the mDRIVE HD 13- and 14-speeds, we’re taking the next step and combining low-speed capabilities with the performance and productivity benefits of our ground-breaking AMT.”

The new models share their architecture with the standard mDRIVE HD, including reinforced internal components and the same gear ratios for the 12 forward speeds. The addition of the low reduction and multispeed reverse gears is made possible by a short extension added to the front of the transmission case. Despite the additional capabilities, the new models are less than 5 in. longer and only 90 lb. heavier than the standard mDRIVE HD, maintaining a weight advantage of nearly 150 lb. compared with automatic transmissions.

For the first time, customers will also have the option to spec the mDRIVE HD in Mack Pinnacle models, including the new mDRIVE models. The new low reduction gears not only improve performance in off-road, heavy haul and construction applications, they enable as well the use of a faster rear axle ratio to improve on-road fuel economy while maintaining startability.

“The mDRIVE HD is just as at home on the highway as it is on the job site,” said Stu Russoli, Mack highway and powertrain products marketing manager. “Highway customers with challenging loads will appreciate the extra flexibility provided by the low reduction gear ratios.”

In addition to the two new models, all Mack mDRIVE transmissions, including the standard mDRIVE and mDRIVE HD, received updates for improved performance and durability. The transmissions are controlled by a redesigned gearbox control unit, while a new clutch with a larger torsional damper helps reduce driveline vibration. Component wear monitors were also added to enable predictive maintenance.

Mack Trucks,