Mack TerraPro concrete pumpers will be available with Mack mDrive HD automated manual transmissions this year, making it the first cabover concrete pumper with an AMT.
The fully integrated 13- and 14-speed mDrive HD is the only AMT with split-shaft PTO functions. Rather than taking power from a transmission- or engine-mounted PTO, the split-shaft PTOs receive output directly from the transmission, supplying higher torques for large auxiliary equipment.
The mDrive HD will be paired exclusively with the 11-liter Mack MP7 engine, and will deliver higher horsepower and torque than equivalent models spec’d with conventional automatic transmissions. This includes the MP7’s top ratings of 425 hp and 1,560 lb-ft of torque, delivering the power traditionally associated with 13-liter engines in an 11-liter package.
It’s available as a 13-speed direct drive or overdrive transmission, as well as a 14-speed direct drive model.
Compared to the mDrive on-highway transmission, the mDrive HD features stronger gears and synchros, and is built to withstand frequent shifting. Integrated low-ratio creeper gears also improve maneuverability at low speeds. There’s also a transmission-mounted oil cooler to help maintain operating temperatures.
Other features include a Rock Free mode, which will help to free stuck vehicles by rocking the truck back and forth with a pump of the accelerator, while Auto Neutral will put the transmission in neutral when a parking brake is set. There’s also a Grade Gripper feature to keep trucks from rolling backward on inclines, and a MaxBrake Performance mode.
The transmission boasts an 800,000-km service interval.