Truck News


Spec’ing for Dumpies

TORONTO, Ont. - As rough as stretches of Trans-Canada Highway may be, they're nothing compared to the operating conditions faced by most dump trucks. Couple the pounding of unfinished roads with grit-...

HEAVY DUTY: Machines for hostile environments.
HEAVY DUTY: Machines for hostile environments.

TORONTO, Ont. – As rough as stretches of Trans-Canada Highway may be, they’re nothing compared to the operating conditions faced by most dump trucks. Couple the pounding of unfinished roads with grit-filled work sites, and you have a hostile environment for all things mechanical.

It’s why the right spec’ing decisions will make all the difference in ensuring a long, productive life for these mechanized pack mules.


When your pay is linked to payload, you’ll want to ensure a design that maximizes the weights allowed in your jurisdiction, and that will require a little bit of homework.

“Some provinces offer an advantage to tandem-steer chassis, while others don’t,” explains Brian Lindgren, Kenworth’s market segment manager for vocational and off-highway trucks. “And the wheelbase requirements for maximum loading can change from province to province. This can have a big influence on how the chassis is configured.”

Aluminum components can also shed weight in many key areas.

“If you had steel air reservoirs or aluminum air reservoirs, you’re not going to give up anything,” says Steve Ginter, Mack’s vocational product manager. It’s why aluminum is a good choice for such things as battery box lids and steps. “But it’s not as simple as steel versus aluminum. There are some inroads into the stronger steel that also aren’t just heavier.”

Sometimes a smaller option can make a big difference in weight. In most cases, for example, a 75-gallon fuel tank will meet your needs. But a 56-gallon version might also be an option.

As well, you can shed about 700 lb. by choosing a 12-litre engine over its 15-litre big brother.

But Ron Singer, a Calgary operator with a mixed fleet of 25 trucks, suggests there’s one area that you can never sacrifice durability in the name of weight.

“You never want to take a lower standard of frame,” he says. And an extra crossmember will typically be needed behind the cab to strengthen the mounting area for a hoist.


Given the uneven ground in most construction sites, the articulation of the suspension will be key to the quality of your ride, as well as the life of your truck.

“If they’re breaking ground when you come in … there are some very demanding oscillation points,” says Singer. “That’s why there’s more air ride in the construction trucking industry than ever before.”

Air rides offer a lighter overall TARE weight, as well as a friendlier ride when the dump body is empty, Ginter agrees. “It’s not just making the seat of your pants feel better … that pounding is a durability issue.”

The pounding can wear out everything from cylinders to pins, and wreaks havoc on plastic cab interiors, Singer says. “You can shake the hell right out of these components.”

“You’ll find it with door hinges,” adds Bob Sugrue of R. Sugrue Cartage in Metcalf, Ont., who has seen that component (and an array of others) wearing out within a year on trucks that ride on poor suspension choices.

But he also suggests looking closely at different designs before choosing an air ride system. Additional bushings, torque arms and moveable parts can translate into complex maintenance.


“For years, the 350-hp dump truck was the staple in the marketplace. Now 400 and up is more common,” Ginter says of the need for power.

Those considering lesser options should also take a close look at the amount of time the truck will be hauling down highways, he adds. “My concern would be that (buyers) are too conservative in what they express to their salesman … some people do not realize how often dump trucks are travelling at 55 mph.”

Given the need for torque, Singer won’t spec’ any transmission smaller than an 18-speed Eaton, enjoying its closer splits. Ultimately, you’ll want to ensure a transmission with a gear that’s low enough to pull through a traditional job site, and high enough to hit highway speeds when heading back to a quarry.

Keep it clean

Job sites are dirty enough. You’ll want to find cabs, components and interiors that are easy to clean. But clean-ups can also involve internal engine components. “I would recommend every owner put on a spinner,” Singer says, referring to his success with oil centrifuges. And Lindgren suggests under-hood air cleaners, with a pre-cleaner to remove large particles and dust before it ever reaches the filter.


“Lift axles, especially steerable ones, are normally over-braked for the load,” Lindgren adds of stopping power. “By including them in the ABS system, they’re less likely to lock up and you reduce tire flat spotting.” And while Sugrue’s personal Peterbilt 357 has a 21.5-foot aluminum box, in a configuration that will handle up to 25 metric tonnes, he suggests that such lengths might not be appropriate for those who spend a lot of time working in new subdivisions: “You won’t make the turns in one shot.” It’s all a matter of taking a close look at the needs of your business, and spec’ing accordingly.

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