Mack making 13 speed AMT standard on Granite trucks in 2017

Mack mDRIVE HD 13-speedMack Trucks’ new 13-speed mDrive HD automated manual transmission (AMT), which features a creeper gear, will be standard equipment on 2017 Mack Granite model trucks, the company announced Monday.

The 13-speed, along with a 14-speed mDrive AMT, was unveiled in March and will be available to order in October.

“Since its introduction, the mDRIVE has become incredibly popular, starting first with highway and more recently with many heavy-duty vocational applications,” says Dennis Slagle, president of Mack Trucks. “The introduction of the 13- and 14-speed gears expands the range and performance in vocational applications so much so that it is only natural for it to become our standard offering in the Granite model.”

Available in direct or overdrive configurations, the new Mack mDRIVE HD 13-speed offers a low-reduction creeper gear ratio designed for easier startability on steep grades or when the truck is carrying a heavy load, allowing customers to select a faster rear axle ratio and decrease engine rpm at highway speeds.

Sharing an architecture with the standard mDrive HD, the 13-speed model includes reinforced internal components and the same gear ratios for the 12 forward speeds.

The addition of the low-reduction creeper and multispeed reverse gears, Mack says, is made possible by a short extension added to the front of the transmission case. Despite the additional capabilities, the new mDrive HD models are less than five inches longer and only 90 pounds heavier than the standard mDrive HD.

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.

The mDrive HD 13-speed is also available on Mack Pinnacle and Titan by Mack models.