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Caterpillar relaunches 651 wheel tractor scraper with productivity improvements and upgrades

Staff Report,

20 Dec 2021

New Advanced Productivity Electronic Control System allows faster cycle times while better operator environment contributes to greater efficiency

Caterpillar has relaunched its Cat 651 wheel tractor scraper (WTS) with improvements and upgrades to the model’s features and specifications for increased productivity, cycle times and comfort.

According to an announcement by Cat, the new single engine 651 WTS re-enters the market with upgrades to its powertrain, controls, hydraulics and structure, which aim to increase its productivity levels and provide a high return on investment for customers.

The new 651 WTS offers 33.6m3 of heaped capacity and a rated load of 46.4t. It shares the same bowl design as the Cat 657 as well as many components, allowing companies with mixed fleets to stock fewer repair parts and lower owning costs.

Cat adds that the scraper’s new Advanced Productivity Electronic Control System (APECS) fully integrates the transmission and engine drivetrain to provide smooth and responsive shifts, allowing the 651 to move more material faster. Its electronic clutch pressure control features 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.

Its single engine design features the Cat C18 engine powering the tractor with 629hp and meets EU Stage V/US EPA Tier 4 Final emission standards. Cat has designed the 651 with the ability to work with a Cat D10 or D11 push dozer for ultra-fast load times, even when working in abrasive or rocky conditions. With its 8-speed transmission reaching a top speed of 56.1km/h, the 651 WTS delivers fast cycle times to improve productivity across a range of applications, from heavy civil construction to quarrying and mining.

The 651 shares the same large cab as the 657 with easy ingress/egress and operator comfort has been enhanced with relocation of the heating, ventilation and air conditioning (HVAC) system to below the cab, while repositioning the steering column and pedal help to improve visibility. The new comfort seat rotates up to 30 degrees to the right for loading and offers an additional 51mm 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.

The scraper’s new high-pressure steering system requires significantly less steering effort, reducing fatigue and improving productivity further into the work cycle. Improvements to the hydraulics include an electrohydraulic implement system for improved multifunction capability and a short throw for the T-handle implement control. Offering a smoother ride, Cat advanced ride management eliminates end-stroke events of the seat suspension cylinder.

Three camera locations for the optional Work Area Vision System (WAVS) show the cutting edge, right side and rear of the machine on a 7-inch in-cab colour display to improve visibility and jobsite safety. Available sequence assist reduces up to 14 individual operator commands per cycle with a single button for improved cycle consistency, less repetitive motions for the operator and reduced fatigue.

Auto-stall, new for the 651, assists in warming up the transmission oil faster when working in colder ambient temperatures, so the machine is quickly ready for work. Configured with sequence assist, the new payload estimator option uses bowl lift cylinder pressure to accurately calculate machine payload to within +/- 5% of actual 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 to lower engine load factor and fuel burn compared to top gear selection. When operating on a decline, 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.

Cat’s standard Product Link on the 651 collects critical machine operating data, including payload, that can be viewed online, connecting the office with the jobsite. VisionLink offers access to this information anytime, anywhere to help companies make informed decisions to boost productivity, lower costs, simplify maintenance and improve safety.


Engine (tractor) Cat® C18
Net power, kW (hp) 436 (585)
Heaped capacity, m3 (yd3) 33.6 (44)
Rated load, kg (lb) 47 200 (104,000)
Weight loaded, kg (lb) 112 945 (249,000)
Top speed loaded, km/h (mph) 56.1 (34.8)


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