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It’s back!: Caterpillar reintroduces 651 Wheel Tractor Scraper

New self-propelled scraper designs don’t come around very often, so when they do it’s big news, especially for any contractor who does high-volume earthmoving.

If you’re not familiar with what these beasts of the field can do, the new Cat 651, with a push from a dozer, can load 104,000 pounds of material in 30 seconds. That’s as much dirt as a 50-ton truck can handle — and it takes at least two and half minutes to load a truck.

Cat has reintroduced its 651 Wheel Tractor Scraper with a bunch of changes, upgrades and enhancements including a new powertrain, controls, hydraulics and structure. This single-engine model offers 44 cubic yards of heaped capacity and a 52-ton rated load. It also shares the same bowl design and many components as the Cat 657, allowing contractors with mixed fleets to stock fewer repair parts and lower owning costs. It replaces the 651E self-propelled scraper, which Cat discontinued about 15 years ago.

A 629-horsepower Cat C18 engine powers the redesigned 651. When paired with a push assist from a Cat D10 or D11 dozer, and its eight-speed transmission, the 651 can load at speeds up to 34.8 mph even in abrasive or rocky conditions.

The scraper’s new Advanced Productivity Electronic Control System integrates the transmission and engine drivetrain to provide smooth and responsive shifts. The electronic clutch pressure control features advanced 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.

For operator comfort, the cab on the 651 is as large as that of a twin-engine 657 and 21 percent larger than Cat’s E-series scrapers. Ingress and egress have been improved with the addition of a powered access ladder. Relocation of the HVAC system, steering column and pedal improve visibility. The new comfort seat rotates up to 30 degrees to the right for loading and offers an additional 2 inches of fore/aft movement to reduce operating fatigue. The seat’s adjustable armrest aligns with the implement control level with T-handle design for more comfortable operation. 

To keep your operators sharper longer, a new high-pressure steering system requires less steering effort and reduces fatigue. Improvements to the hydraulics include an electrohydraulic implement system for improved multifunction capability and a short throw for the T-handle implement control. Cat’s advanced ride management system improves smoothness by eliminating end-stroke events of the seat suspension cylinder

An optional three-camera Work Area Vision System (WAVS) shows the cutting edge, right side and rear of the machine on a 7-inch in-cab color monitor. Available sequence assist reduces up to 14 individual operator commands per cycle with a single button for improved cycle consistency, fewer repetitive motions for the operator and less fatigue.

Production efficiency

When it’s cold out, an auto-stall feature, new for the 651, assists in warming up the transmission oil faster so you can get to work sooner. Configured with sequence assist, the new payload estimator option uses bowl lift cylinder pressure to accurately calculate machine payload to within plus or minus 5 percent of scaled weight, optimizing payload and jobsite efficiency. Using the bowl lift cylinder, the reliable payload estimator system requires no recalibration or operator interface.

The scraper’s new ground speed control allows the operator to set the desired top speed, and the machine will find the gear that works best for the engine and transmission. This lowers the engine load factor and fuel burn compared to top gear selection. When operating on a downhill slope, the 651 detects a machine overspeed situation and automatically engages the compression brakes with no operator input. Hydraulic wet disc brakes replace air actuated brakes from the previous model to improve performance and serviceability. 

Cat651 Quick Specs

Engine: Cat C18, 585 hpHeaped capacity: 4 cubic yardsRated load: 104,000 poundsWeight loaded: 249,000 poundsTop speed loaded: 34.8 mph
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