The new single engine Cat 651 wheel tractor scraper (WTS) re-enters the market with upgrades to the powertrain, controls, hydraulics and structure, designed to deliver more productivity, Caterpillar says.
Offering 33.6 m3 heaped capacity and 46.4 tonnes rated load, the new WTS has the same bowl design and many components as the 657, allowing companies with mixed fleets to stock fewer repair parts.
The scraper’s advanced productivity electronic control system (APECS), a new feature, integrates the transmission and engine drivetrain to provide smooth and responsive shifts, the manufacturer says, enabling the 651 to move material faster. Its electronic clutch pressure control has advance shift control logic for smoother speed and directional shifts, while part throttle shifting controls transmission shifts for smoother shifting between gears. Preventing loss of momentum during shifts, the shift torque management system carries higher torque through shift points.
The Stage V compliant Cat C18 engine powers the tractor with 469 kW (629 hp). The eight-speed transmission reaches a top speed of 56.1 km/h (34.8 mph.
The 651 has the same cab as the 657, with the heating, ventilation and air conditioning (HVAC) system moved below the cab, and the steering column and pedal also repositioned to improve visibility. The seat rotates up to 30 degrees to the right for loading and the adjustable armrest aligns with the implement control level with T-handle design.
The new high-pressure steering system requires less steering effort, Caterpillar says, thus reducing operator fatigue. Improvements to the hydraulics include an electrohydraulic implement system for improved multifunction capability and a short throw for the T-handle implement control. The advanced ride management eliminates end-stroke events of the seat suspension cylinder.
Auto-stall, new for the 651, helps to warm up the transmission oil more quickly when working in colder weather. Configured with sequence assist, the new payload estimator option uses bowl lift cylinder pressure to calculate payload to within +/- 5% of actual scaled weight, Caterpillar says.
The scraper’s new ground speed control allows the operator to set a desired speed limit, and the machine will find the gear that works best for the engine and transmission to lower engine load factor and fuel burn compared to top gear selection. When traveling downhill, the 651 detects any machine overspeed and automatically engages the compression brakes. Hydraulic wet disc brakes replace air actuated brakes from the previous model to improve performance and serviceability.
Standard Product Link on the 651 collects machine operating data, including payload, that can be viewed online, connecting the office to the site. VisionLink offers online access to this information.