Earthmoving Report: Komatsu GD655-5 Motor Grader

Oct. 14, 2010

“Komatsu’s new GD655-5 motor grader squeezes out 20 percent more fuel efficiency than previous Komatsu models in this class, potentially saving contractors up to $4,000 in fuel costs annually,” says Komatsu product manager Steve Moore.

“Komatsu’s new GD655-5 motor grader squeezes out 20 percent more fuel efficiency than previous Komatsu models in this class, potentially saving contractors up to $4,000 in fuel costs annually,” says Komatsu product manager Steve Moore.

Komatsu’s engine technology DNA runs deep in the GD655-5’s power train, employing Komatsu’s own SAA6D107E-1 Tier 3 engine and automatic dual-mode powershift transmission. The three-stage, two-mode engine system delivers up to 218 horsepower, a 9-percent increase compared to previous models, and when the operator selects either Komatsu’s P (power) mode or E (economy) mode, the GD655-5 precisely matches the most efficient engine horsepower to the application.

Komatsu’s exclusive anti-stall function, part of the new automatic dual-mode full power shift transmission configuration, senses when the engine’s speed slows due to increased load demands and automatically shifts into the torque converter mode (auto), thus eliminating stalls and providing continuous smooth power and control in low-speed fine-grading applications. As load demands decrease and the travel speed recovers in applications such as snow removal, the anti-stall feature automatically returns to direct drive (manual) mode. Electronic overspeed protection and transmission controls give the operator maximum performance in eight forward and four reverse speeds.

The GD655-5’s sleek new low-profile 10-foot-6-inch tall patent-pending hexangular-shaped cab gives operators exceptional visibility. The unique Y-shape front pillar design eliminates traditional front pillars and provides an unobstructed view of the moldboard and front work area. A rear side pillar and tapered engine hood with glare-resistant finish allows exceptional attachment visibility.

The 20 percent larger cab has more legroom; floor-to-ceiling, outwardly angled side windows; and a new narrow front console that gives the operator greater freedom of movement and a clear view of the blade. Console-mounted hydraulic controls are in the familiar, industry standard pattern. “Operator office” essentials such as tinted windows, air conditioning, electric rear window defroster, 12V power port, AM/FM radio, and personal storage space are standard features.

The GD655-5’s rugged new design enhances the grader’s performance and serviceability. A 16-inch-longer wheelbase permits an aggressive moldboard angle that throws windrow to the right of the grader, especially helpful in snow-removal applications. The grader’s design positions the engine at the rear, locates the transmission mid-machine, and increases weight on the front axle for better stability and blade control. Ground-level refueling and easy-access oil and coolant service points simplify daily maintenance. A new manual-reversing hydraulic-driven fan blows debris from the radiator to keep the engine cool.

Komatsu builds additional value into its motor graders by creating new standards for what once were custom options. For example, the GD655-5’s standard 10-valve configuration—industry standard is eight valves—provides control and power for implements such as rippers and scarifiers. When paired with the closed-center load-sensing hydraulic system, the GD655-5 provides quick, cool and fuel-efficient implement operations. Other features such as independent left- and right-hand blade float controls, blade lift accumulator, provision for ripper, a Turbo-2 engine precleaner, and the upgraded Komtrax 2.5 machine control system, are also standard.