Challenger Unveils New Track Tractors

New MT700E and MT800E Series have Tier 4 Final engines and patented undercarriage design with Mobil-trac systems, delivering more power to the ground.

Published on: Sep 6, 2013

The site of the 2013 Farm Progress Show in Decatur, Ill., was full of exhibitors showcasing newly launched machinery, technology, and other products. The AGCO lot was no exception, with nine new products, including the MT700E Series track tractors – the MT755E at 350 horsepower, MT765E at 375 horsepower, and MT775E at 400 horsepower. The new MT800E Series, what AGCO refers to as the "beast," includes the MT845E at 450 horsepower, MT855E at 490 horsepower, MT865E at 540 horsepower and MT875E at 590 horsepower.

Both series come with new AGCO Power Tier 4 Final engines. The MT700E Series uses 9.8 liter engines, while the MT800E Series uses 16.8 liter engines. Both achieve Tier 4 Final emissions without using a heat-generating diesel particulate filter. They use a combination of selective catalytic reduction, or SCR, and external-cooled exhausted gas recirculation, or cEGR.

THE BEAST: AGCO recently unveiled the Challenger MT875E at the 2013 Farm Progress Show in Decatur, Illinois. The new MT700E and MT800E Series come with AGCO Power Tier 4 Final engines mounted directly to Caterpillar Powershift transmissions
THE BEAST: AGCO recently unveiled the Challenger MT875E at the 2013 Farm Progress Show in Decatur, Illinois. The new MT700E and MT800E Series come with AGCO Power Tier 4 Final engines mounted directly to Caterpillar Powershift transmissions

"Having a vast majority of SCR and a small amount of cEGR will reduce not only fuel consumption but diesel exhaust fluid consumption as well," says Conor Bergin, product marketing manager for High Horsepower Tractors.

The engines put out more torque and sustain torque for a longer period of time.

"I'm not going to have to shift the tractor down, I'm not going to have to slow the tractor down, and I'm not going to have to lift the tool I'm hauling up because I'm going have the torque to work through those situations," Bergin explains. "The operator is ultimately getting more work done in the day. We can actually run the tractor at lower engine RPMs, which in turn means more fuel savings."

In-line design

The engine is mounted to the Caterpillar Powershift transmission, which sends power directly to the final drive without a drop box, reducing parasitics and improving fuel consumption. This contributes to the in-line design.

"Our engine mounts directly to the transmission and then to the final drive and ultimately to the track system," Bergin says. "All the torque we're creating inside the engine is going through the transmission and going out to the final drives."

This transmission provides a smoother shift, says Ash Alt, field marketing manager for High Horsepower Tractors. "If you have to downshift for some reason, it's not going to jerk you out of the seat," Alt says. "It's a faster shift, so it's less power loss."

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The Powershift transmission includes a power management setting for pulling large implements. When engaged, it automatically downshifts or upshifts depending on the load, providing the maximum horsepower and torque required for the situation. A constant ground speed setting is available for light duty applications, selecting various engine RPMs to maximize fuel efficiency.

Unique undercarriage

A key feature of the tractors is the patented undercarriage with the Mobil-trac system, which uses oscillating mid-wheels, leaving a lighter footprint and reducing compaction while improving ride comfort.

"The oscillating mid-wheels are attached to a walking action axle. They will pivot up and down as we go across the ground," Bergin explains. This gives the track the ability to mold to the ground, walking across it rather than falling over bumps and other obstacles.

"If we're maintaining constant contact across the ground, we're reducing our compaction," he adds.

The MT700E and MT800E Series use a hydraulic cylinder to put pressure to the undercarriage, improving driver-to-belt contact and traction. The cylinder absorbs shock and will smooth the ride out after hitting an obstacle. Hydraulic pressure is displayed on the monitor in the cab, and the operator can increase or decrease tension according to their needs.

The undercarriage includes two Marsh Mellow springs. "It's basically a big fabric rubber spring that will never, ever wear out," Alt explains. Bergin adds the springs attach the undercarriage to the frame of the machine.

"Those springs are going to pivot up and down, so that's going to really help absorb the amount of vibration and shock we experience as we go across the field," Bergin says. "It's allowing those tracks to pivot up and down to ensure we're making constant ground contact."

Rather than using tracks as an aftermarket product, the MT700E and MT800E Series are built from the ground up specifically for this track system, improving balance and ballasting – the ability to add weight to compensate for a load.

"Their balance is 50/50 from front to rear," Bergin says. "So that makes it very easy for us to add or subtract weight if need be when we add an implement to the rear of the machine."

It also improves the ride and allows the engine to be mounted lower. "Our tractor has a lower center of gravity for better balance, better design, but also it allows for that in-line design."