Today’s motor graders—of all sizes—reflect design efficiencies that serve the end user well
The selection of motor grader models in the U.S. market remains expansive—despite the market having stumbled somewhat in recent years—with nearly 50 current models available from 13 manufacturers. The selection ranges from small utility models with less than 50 horsepower—the Laser Grader, LeeBoy 635B, and Basic Equipment 601, for example—to the 533-horsepower Cat 24M, which Caterpillar classifies (along with the 332-horsepower 16M) as a mining grader.
Between these extremes are two general (but sometimes overlapping) motor grader categories, “compact” and “production.” Included in the compact category might be the Champion models (up 120 to horsepower), the NorAm 65E Turbo (114 horsepower), h-MACH Cross Blade (100 horsepower), Mauldin models (133 horsepower), and the LeeBoy 685B and 785 (100 and 129 horsepower).
Motor Grader Ownership Costs
Size (hp) List Price Hourly Rate* 74 & below $71,000 $39.41 75-114 $107,932 $52.79 115-129 $176,990 $56.53 130-144 $233,561 $66.91 145-169 $280,889 $79.64 170-199 $321,871 $91.65 200-249 $389,276 $107.08 250 + $579,930 $148.06
*Hourly rate represents monthly ownership costs divided by 176, plus operating costs. Adjusted operating unit prices used in the calculation: diesel fuel, $4.13/gallon; mechanic's wage, $50.76/hour; cost of money, 2%. Source: EquipmentWatch.com
“Production” machines take in the majority of models in the product lines of such manufacturers as Caterpillar, Volvo, John Deere, Case, Komatsu, and Intensus. Horsepower in this group ranges from 160 to 294, and some larger models might see service in mines, where their primary task is haul-road maintenance.
Along with higher horsepower and heavier operating weights, production-class graders typically use a powershift transmission, most direct-drive (without a torque converter), but some equipped with a converter. A number of compacts, however, have traded hydrostatic drive (the dominant drive system for smaller machines) for a powershift, including the direct-drive Champion C110C and C116C and the torque-converter-equipped NorAm 65E Turbo and LeeBoy 785.
But for the most part, says Shannon Chastain, president of Shannon Chastain Enterprises, manufacturer of Basic Equipment models, hydrostatic drive is well suited to compacts—simple, reliable, lower in cost than the powershift, and providing good low-speed control.
In the past couple years, a number of new production-class machines have been introduced, in some instances to move them to Tier 4-Interim status, but also adding new features along the way.
Caterpillar has eight new Tier 4-Interim M-Series 2 models, along with their all-wheel-drive counterparts, including the all-new 12M2 AWD. The new models have more power and operating weight and feature Caterpillar’s Variable Horsepower Plus system, standard three-axis electro-hydraulic joystick controls (with automatic return-to-center function), automatic-locking differential, and the Cat Grade Control Cross Slope system, a factory-installed option compatible with AccuGrade two- and three-dimensional grade-control systems.
John Deere last year introduced its Tier 4-Interim G/GP Series, 12 models, ranging from 195 to 283 horsepower. G models use conventional control levers, while GP (Grade Pro) models feature electro-hydraulic controls. GP models also provide an automatic-locking differential, one-button return-to-straight feature, and a cross-slope system that allows selecting a slope and maintaining it with just one blade-lift lever. A stall-prevention system senses engine overload and shifts the transmission to neutral to avoid restarts.
Volvo’s new B-Series models—G930B, G940B, G960B, and G946B—have larger-displacement, Tier 4-Interim engines with power and torque curves, says Volvo, to match requirements of the transmission, whether the company’s 8F/4R or 11F/6R configuration, both of which are direct-drive powershifts. Volvo also recently announced a joystick control system that provides an electro-hydraulic alternative to standard controls.
The Komatsu GD655-5, with a powershift transmission that operates in either a torque-converter mode or a direct-drive mode (with the converter locked), now has an anti-stall system that shifts the transmission to its torque-converter mode if a stall is imminent. Other new features include a larger cab, longer wheelbase, added horsepower, and increased operating weight.
The latest models in the Case motor grader line, the B-Series, have Tier 4-Interim engines, larger cabs, redesigned low-effort controls and a new main-hydraulic valve for enhanced control of grading functions.
“Case B-Series motor graders feature a front articulation design that allows the cab to be mounted farther back on the machine, giving operators an unobstructed view of the entire moldboard and ground-engaging tools,” says Paul Wade, brand marketing manager, Case Construction Equipment. “B-Series cabs also have an improved control layout, but maintain the conventional nine-lever configuration that many operators prefer.”
Because motor graders can spend considerable years in service, and, as a consequence, the replacement of these machines might be infrequent in some fleets, a quick review of the production machine’s technical refinement in recent history might be helpful.
Control systems come first to mind, with three manufacturers now offering alternatives to the conventional control system, which connects multiple levers (arranged in an industry-standard pattern) directly to the control valve via mechanical linkage.
Caterpillar was first to offer an electro-hydraulic system (the link between control levers and the valve is electronic) with the introduction of its M-Series models some five years ago. The system, standard on Cat graders, uses two joysticks to replace the conventional levers and steering wheel.
“The joysticks require 78 percent less hand and wrist movement, compared with conventional lever controls,” says Caterpillar’s Wade Porter, motor grader application specialist, “and they provide enhanced operator comfort and efficiency.”
Electro-hydraulic controls for John Deere’s GP models consist of eight, armrest-mounted, fingertip-actuated levers, including a steering lever, arranged in the industry-standard pattern on each side of the steering wheel. According to the company’s Mike Ackerman, product manager for motor graders, retaining the industry-standard arrangement for the new controls allows both beginning and seasoned operators to quickly become productive with the machine.
Volvo recently introduced an optional, two-joystick, electro-hydraulic control system, but retained the steering wheel, which must be used above 18 mph to allow the transmission to shift to higher gears. According to Volvo’s Gary Atkinson, district sales manager, the hydraulic response of the new joystick system can be tailored to the operator, and three operator profiles can be stored.
Refinement of variable-horsepower (VHP) systems, available on many models, is another significant advancement. VHP systems essentially tailor machine performance to the task at hand, restricting horsepower in lower gears for traction-limited tasks—when too much power might spin the drive wheels—but adding horsepower in higher-gear applications.
“Motor graders are unique in that they are applied in a variety of applications that might require from 60 to 100 percent of their net horsepower, and they’re required to perform efficiently across this broad range of power requirements,” says Komatsu’s Steve Moore. “Variable-horsepower allows them to be consistently efficient as applications change.”
Says Caterpillar’s Porter: “Limiting power saves fuel, helps protect the drive train, and minimizes tire wear. But it’s very important that a motor grader have the right amount of base power to effectively handle heavy-duty applications, like ripping.”
Extra power in higher gears, says Porter, allows machines to attain higher travel speeds, climb steeper hills without downshifting, overcome power drains that increase with speed (such as increased rolling resistance), and to handle heavier loads at high speeds.
Notable drive-train and hydraulic refinement might include more precise electronic control of the powershift transmission, adjustable hydrostatic front-wheel-assist systems, and load-sensing hydraulics that allow simultaneous operation of multiple hydraulic functions.
Productivity and serviceability enhancements include easier-to-use cross-slope systems and factory integration of support components for automated grade controls; telematic systems, standard on many machines, that assist in improving machine utilization and maintenance; and simpler systems for maintaining moldboard adjustment, resulting in grading precision and reduced downtime.
On the compact side of the business, says Dave Watson, vice president of NorAm, the work slowdown in the private sector and leaner governmental budgets, in some instances, have been a positive factor.
“We’ve seen a number customers who couldn’t afford a full-size grader opt for a compact that handled their applications at a lower cost,” says Watson.
Bryan Abernathy, vice president of Champion Industries, is encouraged by a recent increase in municipal bids, as well as increases in rental-company purchases and dealer stock orders. But that said, Abernathy estimates that the compact side of business “will stabilize at perhaps 60 percent of pre-recession levels.”
On the production-class side of the market, John Deere’s Ackerman is optimistic: “The economic slowdown definitely affected motor grader sales, but, that said, the market is recovering—not yet to levels prior to the downturn—but showing a positive outlook as road and site-development projects receive funding.”
Caterpillar’s Porter agrees: “The market has significantly rebounded from the economic downturn. Appropriated funding is available for governmental agencies to replenish fleets with new machines, the private sector is seeing an increase in available projects, and the mining industry is at an all-time level in demand.”
Overall trends in the marketplace, from Porter’s perspective, include buyers across all market segments “upsizing” to larger machines; a growing interest across all segments in “life-cycle-cost” buying practices—“looking beyond the initial purchase of the machine to all other costs associated with ownership and operation, including fuel-burn rates and resale value,” says Porter; a keen interest in production capability (especially among private-sector contractors); and a more intense focus on machine reliability/availability (especially among mining customers).