The guy who buys this truck could be in for a surprise. Typically, dump trucks trade on 5- to 10-year cycles so its future owner could be jumping out of a mid-1990s-vintage CL- or R-model into this CT 713 Granite. Technologically speaking, that’s quite a jump.
Mark Willie, sales manager at Peel Mack in Mississauga, Ont.-the good folks who set up this drive for Today’s Trucking-says that at trade time, he often hears customers asking for the same truck they had before.
“They’re used to the way the truck works, and it suggests they’re happy with what they have,” says Willie. “But we don’t make that truck any more. We’ve moved a long way forward in terms of technology and materials. The truck is necessarily going to be different, and better, but it’s a big step for someone who trades on five-, eight-, or even 10-year cycles.”
The most obvious change, of course, is under the hood. Mack’s ASET AI engines use internal EGR to meet EPA’s emissions mandate. Typically, that means a larger block than before, producing higher horsepower and more torque. There are fuel-economy concerns with the newer engines, but they’re a fact of life with EGR.
When you dig a little deeper into Granite, you find more change. Again, solid improvements, but not the same truck as before.
Take Mack’s new “Cornerstone” vocational chassis for example. Introduced in 2004, it uses high-strength, low-alloy steel that’s tempered to a minimum of 120,000 psi. Single frame sections can manage applications where operators traditionally spec a double frame, or at least a liner. Granite’s 11.1mm frame is at least as strong as an old-style double frame weighing considerably more, but liners are still available for specific applications-and of course customer preference. Granite’s crossmember packages are application-specific, but all feature a back-to-back design for optimum strength-to-weight ratio.
Granite’s set-back axle configuration gives operators the flexibility to spec a 20,000 lb front axle. Add a pair of 425 steer tires and you can take the front-end load right to legal maximums in Canada. And with the shorter wheelbase comes improved maneuverability. Cornerstone’s chassis and outboard steering box gives the Granite Axle Back one of the tightest turning radii in the business.

Fringe Benefits
The front of the frame is flared to accommodate a larger radiator for increased cooling capacity. Two cooling packages are available in the Granite Axle Back truck. The standard 991-sq-in radiator core is five-percent larger than the previous model, while the enhanced package features an 1170-sq-in rad-25 percent larger than the standard unit-available only on trucks without a front-end PTO.
A transmission oil cooler is integrated into the lower tank of the rad, and the fan has been upsized from a 25.9-in diameter to 26.7. The fans can be driven by on/off clutches (a Borg Warner was installed in our test truck) or electronic modulated fan drives (EMFD) controlled by the engine’s electronic control unit. This version offers smoother fan engagement as it ramps up to speed as compared to the harsher engagement of an on/off fan drive.
On a job site, less fan-on time means less dust thrown up, and a quieter working environment for the driver. And Granite is quiet. During our four-hour drive, I never found it necessary to raise my voice to talk with my tour guide, Mark Willie.

I’d call Granite Axle Back a very driveable truck, and not a bad place at all to wile away a work day. The cab is roomy enough, and quite a step up from the
R-Model. It’s quiet, and the visibility is noteworthy. The grated clutch pedal is a nice touch given the likelihood that the driver will be riding the clutch with muddy boots. You’d have a hard time slipping off that pedal.
The 18-speed’s low-gear ratio of 12.19:1 gives the operator an ideal creeper gear for spreading, and even at highway speed the engine stays at a reasonable rpm. This powertrain has latitude not offered in the 8- or 9-speed boxes often found in older models.
We scaled out at 52,860 lb with a partial load of topsoil. Not much of a workout for the ASET 460, but enough to get a sense of how it managed hills and how it rode. We left the dealer in Mississauga and headed for Halton Hills, north of Milton, just west of Toronto. We pulled a few six- and seven-percent grades and it hardly broke a sweat. On the down slope, Mack’s PowerLeash retarder did an admirable job.
The Hendrickson lift axle responded quickly when dumping the air prior to a turn, but you have to remember to flip the switch. I forgot on one turn and continued skating straight ahead before I dumped the air, just before hitting the curb. Live and learn. The steering was firm, if a little stiff. You could palm the wheel in a turn, but you’d be pressed to one-finger it. Still, that firmness made for a nice feel on the highway, and posed no particular difficulty in the dirt.

The 460 ASET certainly got the job done, so full marks there. The driver environment is clean and uncluttered with terrific visibility fore and side. It’s a very quiet cab, even with the fan running. It doesn’t ride like a dump truck, so that’s a plus, and I’d have to say it’s got a ton of curb appeal too.