Mack launches automated manual transmission

| March 25, 2010

Mack Trucks introduced its new Mack mDrive automated manual transmission at a press event today, March 25, in Louisville, Ky.

The company said the mDrive AMT gives customers up to 1.5 percent improved fuel efficiency, better driveability and enhanced driver satisfaction by automating gear shifting, while improving safety.

Mack also introduced Econodyne engine ratings to maximize fuel economy; its new C150/151 family of rear axles, with new gear ratios tailored for the MP engine series; a new cab-mounted exhaust for the Granite model; and the standard fitment of Bendix ES (extended service) foundation brakes.

Designed and engineered to work exclusively with MP engines, mDrive will be available on Pinnacle model highway tractors powered by MP7 and MP8 engines. Customers may order the new mDrive now, with deliveries to begin early in the fourth quarter of this year.

“mDrive boldly expands Mack’s leadership in heavy-duty powertrains,” said Kevin Flaherty, Mack senior vice president of sales and marketing. “To be considered Pedigreed, the engine, transmission and axles must be all Mack, providing performance and fuel economy second to none.”

The mDrive has 12 forward and four reverse speeds, and is available in direct drive or overdrive. It has a torque capacity of 1920 lb.-ft. and a dry weight of 615 pounds. The shifting strategy for mDrive is optimized for North American highway conditions and is based on cruise speeds of 1350 to 1450 rpm for best performance and fuel economy.

The driver interacts with mDrive through a dash-mounted control pad containing manual input and hold shift buttons, with an integral display indicating the current gear. In addition, the Mack Co-Pilot driver display in the center of the instrument panel provides the driver with transmission status, including the number of upshifts or downshifts available, the current gear and the current operating mode (such as Economy or Performance). The transmission’s Economy mode maximizes time spent in top gear, while Performance mode maximizes gradeability.

An additional MackCellerator or kick-down feature drops the transmission one gear (while synchronizing engine RPM) when the accelerator pedal is sharply depressed to maximize acceleration in passing situations. mDrive also provides an optional Grade Gripper, or hill start assist, when launching the truck on an incline to prevent the vehicle from rolling backward. It also detects if the tractor is attached to a trailer and automatically reduces torque output if the tractor is bobtailing, which saves fuel.

mDrive is available in two versions: Fleet and Premium. The Fleet package includes basic shifter controls, with Grade Gripper and MackCellerator as options. The Premium package consists of a shifter with more features for greater driver control, including manual shift inputs, performance and economy modes, plus Grade Gripper and MackCellerator. mDrive is available with two optional rear-mounted power takeoffs.

Econodyne: The latest generation of the Econodyne engine family for highway applications delivers more torque at low engine speeds for improved fuel efficiency and hill pulling performance. The new Econodyne uses an intelligent torque management strategy called EconoBoost that gives drivers the extra muscle to keep vehicle speed constant under full engine loads to avoid downshifts. Econodyne is available now with the MP7 and MP8 engines in the Pinnacle.

EconoBoost initiates at 1300 rpm after four seconds of full throttle in the transmission’s top two gears, opening up another 200 lb.-ft. of torque for as long as needed. It disengages once the driver lifts off the throttle and driveline torque drops to negative, such as when a hill is crested. It delivers more than 90 percent of power after an upshift without driveline shock.

Rear axle carriers: Mack said the new C150/151 rear axle carriers are lighter, stronger and stiffer than previous designs while retaining the company’s top-load dual-reduction design, and are compatible with all the company’s suspensions. The top-loaded carrier – where the driveshaft connects to the carrier above the axle – results in near-zero driveline angles, which minimizes noise, vibration and harmonics.

Potential oil leak paths are reduced since the carrier joint is on the horizontal plane above the level of the oil reservoir. Dual reduction reduces gear face friction and related parasitic losses, component stress and excess heat, increasing overall component life.

Mack’s power divider is standard with the C150/151 carriers, with an optional power divider lockout and optional differential locking systems. Rear axle ratios run from 3.11:1 to 5.66:1.

Cab-mounted exhaust for Granite: The Granite’s new optional cab-mounted exhaust is attached vertically to the cab’s right hand B-pillar so it doesn’t take up back-of-cab space, which eases body installations and may allow the use of a shorter wheelbase. The cab-mounted exhaust is available now as a customer-specified option on all Granite models.

Bendix ES standard foundation brakes:  The Bendix ES (Extended Service) are now the standard foundation brake for all Mack truck models; other brake systems, including the Bendix Air Disc, remain available options.

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