Mack® mDRIVE™ HD paves the way forward for vocational

Mack’s automated manual transmission (AMT), the Mack® m DRIVE ™, has been a hit for over-the-road trucking since its introduction. A lighter weight, lower cost transmission that improved fuel economy and driver comfort—what wasn’t to love?

“We had a lot of early adoption on the highway side, so there has been the most opportunity for drivers to see the benefits of m DRIVE on the Mack Granite^®,” says Tim Wrinkle, senior product manager, vocational and medium duty.

“Now, we’re seeing growth across the board.”

That’s because customers are seeing how the Mack m DRIVE HD is designed to stand up to on- and off-road service and to help drivers focus more on their job-specific tasks as they operate the truck. Such is the case with Granite models spec’d to carry out various vocational applications, especially in this era of driver shortages. Spec’ing trucks for these applications is all about delivering power and performance at the jobsite while easing the workload demands on drivers there, plus ensuring fuel-efficiency and vehicle durability.

Each application has nuances, and the m DRIVE HD has many features for drivers to take advantage of that offer so much productivity. In fact, the m DRIVE HD comes standard on the Granite.

Features include MackCellerator, which optimizes vehicle acceleration; Grade Gripper, which provides anti-roll back assistance during transition from a stopped position to starting on a grade; Idle Drive Mode, which allows slow speed vehicle maneuvering such as at a dock or in slow moving traffic; Rolling Start, which allows the driver to go to directly from Neutral to Drive without a Service Brake application; and Auto Neutral, which puts the m DRIVE in neutral when the parking brake is set, improving jobsite safety.

Smooth and quick

“What’s key for me is providing my drivers with a safe and comfortable environment to do their job,” says Gary Grewal, president of GBA Haulage of Brampton, Ontario.

Launched in 1998, GBA provides gravel, paving, road resurfacing, and excavation services in the Greater Toronto area.

“The m DRIVE transmission has proven to reduce driver fatigue. My drivers love it. They find it smooth and quick. In fact, they refuse to drive anything else.”

For Bee Line Ready Mix, the initial impetus to switch from automatics to the m DRIVE was to cut the weight of the fleet’s transit mixers. “The m DRIVE HD is the first automated manual we’ve run,” says Paul Black, vice president of the Lavon, Texas-based firm. “Mack’s automated manuals shave 300 pounds off the truck’s weight. That matters. We make more money with less weight,” since lighter components mean the truck can legally carry more concrete.

Bee Line, which started up in 1993, operates a batch plant and delivers ready mix to job sites in the Dallas- Fort Worth metroplex. It offers a range of other services as well, including concrete and asphalt repairs.

The 12-speed m DRIVE HD is available with optional 13- and 14-speed “creeper” gears. Offering this extra gearing reflects how Mack aims to deliver excellence for roadbuilding applications, adds Wrinkle.

Flexible gearing

“With two additional low gear ratios plus multi-speed reverse gears,” he explains,” this transmission is designed to provide flexible gearing for low-speed operations and improved startability for heavy loads. It also maintains proper gearing for fuel efficiency at speed and saves wear and tear on clutches and brakes.”

The premium version of the m DRIVE is controlled through a dash-mounted shift pad by selecting drive, neutral, reverse and mode. To complete more demanding jobsite maneuvers, the premium shift pad can be operated manually to hold a gear, downshift, or upshift as needed. The mode can also be changed to give optimal fuel economy or off-road performance.

Josh Seiferth, Mack LCOE (low cabover) product manager, points to a specific application advantage for concrete pumpers: The m DRIVE HD is “tuned for them, in that the transmission’s split shaft PTO functionality allows the high torque levels needed to provide more power to the pumps. This ‘split box’ functionality is controlled by special software. Not all AMTs have this capability.”

In addition, the MP engines' performance is carefully calibrated to handle close speed control under stressful pumping operations, says Seiferth. The m DRIVE HD can be set to hold MP engines to the correct RPM level for pumping so that with very little effort from the operator, the truck drives the pumping operation with ease. "This Mack powertrain combination is a game changer for concrete pumper applications," he says.

Mack provides the concrete market with the industry-leading share of concrete pumpers, both the TerraPro™ low cabover and the Granite.

The m DRIVE in roadbuilding applications is “a key in driver comfort and retention,” Wrinkle says. “It makes the job easier for drivers at job sites and on the highway. It reduces driver fatigue and helps them focus on the task at hand.”

m DRIVE ordered with Premium Shifter will also have the “Rolling Start” functionality built in. This function allows a driver to go directly from neutral to drive without applying the service brake. This feature is especially desirable in paving applications to avoid stopping the paving machine and causing material (asphalt or concrete) to make a lump when the dump truck in neutral is being pushed along by the paver.

Offered in overdrive and direct drive, m DRIVE HD continuously monitors changes in grade (both up and down), vehicle speed, throttle position, acceleration, torque demand and gross vehicle weight. It automatically chooses the best gear for the road condition so that drivers can concentrate on the terrain and their tasks rather than on shifting gears.

The m DRIVE HD is only offered for the Mack MP^®7 and Mack MP^®8 engines.

Shop and fuel savings

“All of my fleet uses Mack’s m DRIVE transmission. Before buying Macks, I was using 18-speed manual transmissions,” says GBA Haulage’s Gary Grewal. “The fleet is currently made up of 21 Macks. I use 17 Granite tri-axle dump trucks and recently bought four Mack Anthem^® tractors for the ‘live-bottom’ part of the business.” He explains that rather than dumping a load of gravel or asphalt like a typical dump truck, a live-bottom trailer pushes material out the back via a conveyor belt bed.

Grewal says he opts to run with Mack for several reasons. “I can rely on these trucks, and I can trust that my drivers are able to get their job done efficiently and safely. The Granites are proven and the Anthems, although new to my fleet, have been a welcome addition.”

Along with increasing driver satisfaction and productivity at job sites, Grewal says the switch to the m DRIVE transmission has yielded savings in the shop. “My maintenance costs have gone down big time,” he relates. “The manual transmissions were constantly in for service, whether for clutch, u-joint, or bearing issues. That’s all a thing of the past now.” He adds that Macks’ after-sale support is also a factor, noting that “my dealership has always treated me well.”

Then there’s fuel, the cost of which is a growing concern for everyone. “m DRIVE, as proprietary, is designed from the ground up to be paired with our engine seamlessly to maximize both performance and fuel economy,” explains Wrinkle. “Customers coming from other products see a weight reduction and fuel benefit.”

Grewal says he did the math. “When I learned from my Mack salesperson that I could be saving considerably on fuel by opting for the m DRIVE transmission, I was skeptical,” he says. “But I’ve done the comparison over the years, and I’m seeing a savings of CAD$40 to $50 ($31 to $40 USD) per day, per truck. That goes straight to my bottom line.”

On/Off excellence

That the transmission helped trim mixer weight by several hundred pounds was just the starting point at Bee Line Ready Mix. “We started with the m DRIVE on our Granite transit mixers, which we’ve put in service since 2018,” says Black. Those are tandem-axle, rear discharge mixers.

The fleet runs 37 of these trucks to transport ready mix from its batch plant to job sites, where the product is discharged into concrete forms or concrete pumpers. The transit mixers also provide ready mix for city street repairs, commercial parking lot maintenance, and new residential construction.

Bee Line also fields 14 Mack Pinnacle™ models with end-dump trailers, which pick up concrete aggregate materials from quarries and haul it to the company’s batch plant.

Black says that the m DRIVE excels in on/off- road operation in this application as well.

“We’re ‘Gold Bulldog’ with all our trucks,” Black relates. “They are all spec’d with Mack engine, transmission, and rear axle. We only have to go to our Mack dealer for service; they take care of their customers.” Servicing their previous vendor transmissions meant “dealing with a whole other network” outside the OEM channel, which adds time and complexity.

He says that out in the field, the m DRIVE HD stands out with its gearing. “Fourteen speeds give you a good selection to work with. The crawler low gear helps especially with getting the truck through wet fields at job sites.

Sink not

“Our drivers like not having to shift. And they like knowing they can just push a button to lock the rear-axle differential, put the truck in low gear, and know they will get in and out when off-road. [Even during Texas' rainy season] you still have to pour concrete. The job site may be so muddy that the mixer might sink six to twelve inches into the ground. The drivers like knowing they will still get out.”

In both of Bee Line’s truck applications, the m DRIVE HD is performing “better than expected,” Black reports. “Soon after switching, we found that transmissions were no longer on our list of ‘things to watch for.’ Really, they’re bullet-proof— even when running on and off the road all day.”