Wheel Tractor Scrapers have dual power capabilities.

Press Release Summary:

Models 621G, 627G, 631G, and 637G offer operator stations that promote efficient operation, low-profile scraper bowl, and EMS III electronic monitoring system. Electronically controlled engines feature Caterpillar HEUI(TM) fuel system and comply with current EPA emissions regulations. Other features include automatic planetary powershift transmission, single lever implement control, bulldozer ejection system, and grouped maintenance and service points.

Original Press Release:

Caterpillar Improves Four Models of Wheel Tractor Scrapers

The Caterpillar® 621G, 627G, 631G and 637G wheel tractor scrapers have been improved to boost productivity and lower operating costs. Both the 627G and 637G tandem-powered machines have new electronically controlled scraper engines that incorporate dual power capabilities, just as the tractor engines do. Each of the four scrapers has a new productivity enhancing operator station, a redesigned scraper bowl with 10 percent more capacity, and the latest electronic monitoring system to simplify maintenance. The 627G and 637G now incorporate the Cat® C-9 scraper engine for peak performance and high productivity in self-loading applications. Dual horsepower capabilities enable the scraper engine to produce more power in higher gear ranges for improved gradeability and reduced cycle times. The 621G standard scraper and 627G tandem-powered scraper both use the Cat 3406E tractor engine. The engine produces net power of 330 hp (246 kW) in lower gears and 365 hp (272 kW) in higher gears. The C-9 scraper engine on the 627G produces 225 hp (168 kW) and 249 hp (185 kW). Heaped bowl capacity is 22 cubic yards (17 cu m). The 631G standard scraper and 637G tandem-powered scraper both use the Cat 3408E tractor engine. The engine produces net power of 450 hp (336 kW) in lower gears and 485 hp (362 kW) in higher gears. The C-9 scraper engine produces 249 hp (186 kW) and 274 hp (204 kW). Heaped bowl capacity is 34 cubic yards (26 cu m). The electronically controlled engines feature the Caterpillar HEUI(TM) fuel system and comply with current EPA emissions regulations. Each engine is electronically integrated with, an automatic planetary powershift transmission to provide maximum power to the cutting edge and high-production haul road speed. Redesigned operator station enhances productivity The redesigned operator station promotes efficient operation throughout the entire work shift. A new, adjustable Cat Comfort Cloth Seat includes adjustable armrests, and it swivels and locks in four different positions to provide the optimum operating position in the cut or on the haul. The seat suspension features a self-contained air compressor with a high performance air shock absorber. The revised steering column increases legroom. The redesigned hood has sloped corners to enhance sight lines. The exhaust is located at the back of the hood for enhanced sight lines to the right of the machine. The improved scrapers retain the single lever implement control, which combines the traditional three implement levers-bowl, apron and ejector-into one joystick. The operator can raise and lower the bowl and actuate the apron and ejector with the single joystick. On appropriate models, a trigger on the joystick controls the auger or the bail. The transmission hold and cushion hitch switches are incorporated into the joystick as well. Bigger, stronger scraper bowl The redesigned scraper bowl increases bowl capacity 10 percent for each machine. The new design also improves draft arm protection and load retention. The low profile design offers less resistance to incoming materials, and cellular construction adds strength and dent resistance to the bowl sides and floor. The bulldozer ejection system provides constant spreading control while minimizing carryback. A spill guard on the ejector helps retain material and keep it from spilling onto the rear of the scraper. Designed to reduce service time The Electronic Monitoring System, EMS III, monitors machine status and provides real-time information to the operator. The system warns of any problems detected by the electronic control modules governing all major systems. The Caterpillar Electronic Technician service tool easily accesses real-time and stored information through EMS III. The design allows a service technician to diagnose a problem quickly and easily. Caterpillar has made a number of small changes to the scrapers to improve reliability, durability, and access for service. For example, the implement valve has been relocated from the tractor to the top of the draft tube on the scraper. The change eliminates several hoses and tubes that crossed over the hitch. The result is fewer hydraulic components and connections and improved access. The G-Series scrapers also feature grouped maintenance and service points for simplified routine maintenance. Fluid filters are all spin-on style with the exception of the main hydraulic filter. Spin-on filters decrease maintenance time and reduce the chances of system contamination. Auger and push-pull arrangements Each of the four scrapers is available with an auger system in the bowl, which gives a machine self-loading capability in a wide range of material ranging from free flowing to rock. The auger lifts material off of the cutting edge, conditions it and spreads it evenly in the bowl. In addition, the auger minimizes production of dust while loading material. The 627G and 637G are available in a push-pull configuration designed for two machines to assist each other when loading. The push-pull arrangement features a hydraulically actuated bail and cushioned plate bolted to the front of the tractor and a hook attached to the rear of the scraper. The arrangement allows a pair of machines to link together when loading. Typically, push-pull scrapers achieve high production and low cost per yard The improved 621G, 627G 631G and 637G wheel tractor-scrapers build on proven Caterpillar designs. For more information, customers should contact their local Caterpillar dealer or visit the Cat web site at www.cat.com. Basic Specifications for 621G, 627G, 631G and 637G

621G 627G 631G 637G Engine Cat 3406E Tractor: Cat 3406E Cat 3408E Tractor: Cat 3408E Scraper: Cat C-9 Scraper: Cat C-9 Engine power 330-365 hp T: 330/365 hp 450/485 hp T: 450/485 hp (net) (246/272 kW) (246/272 kW) (336/362 kW) (336/362 kW) S: 225/249 hp S: 249/274 hp (168/185 kW) (186/204 kW) Transmission 8F/1R, pwrshft 8F/1R, powershift 8F/1R, pwrshft 8F/1R, powershift Heaped capacity 22 yd³ (17 m³) 22yd³ (17 m³) 34 yd³ (26 m³) 34 yd³ (26 m³) Rated load 52,800 lb 52,800 lb 82,200 lb 82,200 lb (23 9.50 kg) (23 950 kg) (37 825 kg) (37 825 kg) Operating weight 70,458 lb 82,773 lb 102,460 lb 112,760 lb (empty)* (31 9.58 kg) (37 545 kg) (46 475 kg) (51 147 kg) Max. travel speed 32 mph 32 mph 33.2 mph 34.1 mph (51.5 kph) (51.5 kph) (53.5 kph) (54.9 kph) Max. cut depth 13.1 in. 13.1 in. 17.2 in. 17.2 in. (333 mm) (333 mm) (437 mm) (437 mm) Max. spread depth 20.6 in. 20.6 in. 18.9 in. 18.9 in. (522 mm) (522 mm) (480 mm) (480 mm)

*All of the models are available with an auger scraper for self-loading and a broader material appetite. The auger attachment adds approximately 10,000 lb (4365 kg) to the total machine weight.