Product Report: Dynamic dozers

With the newest addition to their crawler dozer line, Komatsu enhances the number one maintenance item on a dozer – the undercarriage. The D475A-5E0 features Komatsu’s K-bogie undercarriage, but with the addition of an eighth roller.

The additional roller means more track on the ground, reducing vibration on rough terrain. The undercarriage system oscillates with two fulcrums to increase track roller vertical travel. Since the track rollers are always in contact with the track link, the durability of components is improved while reducing the impact load. The changes are a substantial improvement to the undercarriage, says Chuck Murawski, product manager for crawler dozers, Komatsu. “You have better traction and less slippage,” he says. Shoe slippage is minimized by a consistent length of track on the ground.

With an operating weight of 238,960 pounds, the dozer features an air-to-air, after-cooled Tier 2 diesel engine with a maximum net output of 890 horsepower, or 860 horsepower with the hydraulic fan at maximum speed. The D475A-5E0 uses an Electronic Controlled Modulation Valve, a new powertrain electronic control system that automatically controls stroke ratio of steering clutches and brakes depending on the degree of the load, reducing counter-steering during downhill dozing. Blade capacities for the dual tilt dozer are 35.6 cubic yards for the semi-U and 45 cubic yards for the U dozer blade.

The Vehicle Health Monitoring System is standard on the D475A-5E0. VHMS monitors the status of major components and enables remote analysis of the machine, reducing repair costs and downtime.

Komatsu also addresses creature comforts, especially noise levels. The cab interior is lined with sound absorbing material and features an insulated double floor, thicker glass in the door and improved pressurization on window seals. Sound absorbing material also lines the air inlet ducts and the double insulated engine hood, which helps maintain an in-cab 70 decibel level. The dozer also comes with the Palm Command Control System, allowing you to control the machine’s travel, the blade and the ripper with a joystick.

D275AX-5 steps up to Tier 3
Komatsu’s 109,900-pound D275AX-5 dozer now features a new turbocharged, after-cooled “ecot3” diesel engine. The Tier 3-complaint engine delivers 449 horsepower at 2,000 rpm, or 410 horsepower with the hydraulic fan at maximum speed. The dozer also has an automatic torque lockup system that automatically engages the torque converter lockup clutch and transmits all the engine power directly to the transmission.

Murawski says the D275AX-5 has measurable improvements in productivity. “This machine has 10 percent less fuel consumption and 10 horsepower more than the previous model,” he says.

In addition to the ecot3 engine, the D275AX-5 has substantial upgrades to other systems. The dozer’s cooling system has an air-to-air charge air cooler and an aluminum radiator; a blade control valve optimizes fine control; a two-micron filter and water separator improve fuel filtration; the hydraulic hoses now have o-ring face seal fittings instead of taper fittings and the cab has a FOPS roof.

Other improvements include a hexagonal cab design with larger, tinted glass windows and a cab damper to increase shock absorption. Murawski says the dozer blades, which offer 17.9 cubic yards capacity in the semi-U and 21.7 cubic yards in the U dozer blade, have been moved closer to the cab. “It’s 16 to 18 inches closer, so you can really dig down,” he says. “It increases productivity by 15 percent.”

All Komatsu Tier 3 machines are equipped with Komtrax technology, a fleet monitoring system capable of tracking data such as fuel levels, load ratios and usage.