Mack Trucks is expanding its medium-duty vocational specs by making available for order the Allison 3000 RDS transmission on its Mack MD Series trucks, the OEM announced at a media briefing at the Work Truck Show in Indianapolis.

Making the Allison 3000 an option was a “strategic decision” to allow for vocational applications that require more power but are best suited to operate medium-duty vehicles, pointed out Dayle Wetherell, Mack vice president of medium-duty sales.

"The transmission enables customers to haul more payload and utilize a live power PTO, both of which are critical for our customers desiring a medium-duty vehicle that can handle demanding applications,” he said.

Mack previously had only offered the Allison 2500 RDS for its MD Series models.

Wetherell said the Allison 3000 provides greater versatility for customers operating 4x2 trucks in such applications as refuse, tank, and dump trucks.

When spec’ed with the 3000 RDS transmission, MD Series trucks are approved to carry a 33,000-lb. gross vehicle weight rating (GVWR) for refuse and recycling applications, The Allison 3000 also allows for a “live-power” power takeoff for MD tanker trucks that deliver heating oil, water, fuel and propane, and dump trucks. That PTO setup enables such vehicles to move while using the PTO at the same time.

"The ability to have a direct-drive PTO is extremely important for some of Mack's medium-duty customers, because they can lift and lower a dump body while driving without worrying about what gear the truck is in,” explained Tim Wrinkle, Mack construction product manager. “It's also important for snowplows and salt spreaders that need to work at the same time.”

Wrinkle said that the Allison 3000 RDS also provides for a higher gross combination weight rating (GCWR) of 45,000 lbs. That higher limit lets customers pull utility trailers with small excavators behind an MD dump truck.

The Mack MD Series equipped with an Allison 3000 RDS will have a GCWR of 45,000 lbs. And the Mack MD Series can be spec'd to be a Class 6 with a GVWR of 25,995 pounds and a Class 7, with a GVWR of 33,000 pounds. Those ratings together mean that Mack now offers a lineup of vehicles running from Class 6 to 8.

Wrinkle noted that the Allison addition indicates Mack is aiming at more vocational choices for its medium-duty customers. He said the optional transmission goes in the order book next month and production is to start in July.