The addition of the field-proven John Deere Tier II 6.8 liter engine to these models enables the machines to meet the toughest emissions regulations in North America, but not at the expense of power. In fact, it produces 185 net horsepower compared to the previous engine's 155-160 net horsepower. With improved low-end operating torque and power, performance and productivity receive a significant boost.
The engine also features an electronically controlled, high-pressure fuel-delivery system. This new system provides a more consistent and precise way to deliver fuel over the entire spectrum of engine speeds and machine applications. The result is enhanced uptime through improved reliability, and performance that's fine-tuned to the ground for a significant productivity boost.
Other enhancements to the machines included changing the fuel and hydraulic tanks from plastic to steel, and increasing capacity in both. The fuel tank went from 100 to 106 gallons, so the operator can work longer without having to stop for re-fueling. The hydraulic tank also was enlarged to hold 15.5 gallons. Re-designed rear service doors open wide for easy access to service points - they're also easy to lift off when a technician needs to reach the cooling package for maintenance.
Sheet metal changes result in increased air flow over the radiator, hydraulics and transmission coolers. New, flat intake screens ensure easier trash clean-off, and a new fan shroud plate provides easier access to the cooling system.
John Deere engineers worked with a customer advocate group to evaluate customer-driven enhancements to the machines. Contractors were brought in from across the U.S. to provide feedback, from owner-operators to representatives of large national construction companies.
One of these contractors was Jerry Pate, owner of Priority Contractors in Concord, N.C. Pate put one of the updated motor graders to work grading stone base on a pavement job in Monroe, N.C.
Source: John Deere, April 1, 2004