631G Wheel Tractor Scraper

Caterpillar Wheel Tractor-Scrapers offer fast cycle times, with quick loading, high travel speeds and the ability to load and dump on the run. Rugged construction and easy maintenance assure long life with low operating costs.

Power Train Engine

A combination of innovations working at the point of combustion, ACERT technology optimizes engine performance while meeting regulations for offroad applications.

Cat C18 Tractor Engine

The tractor for the 631G is powered by the C18 engine with ACERT Technology. The large displacement and high torque rise provide optimal performance in the load, cut, haul and return. Matched to the high efficiency torque converter and electronically controlled power shift transmission, it will provide years of dependable service.

Cat C9 Scraper Engine

The 637G has a C9 engine with ACERT technology which provides additional power to assist in loading as well as improved hauling performance on grades.

ACERT Technology

Caterpillar optimizes engine performance while meeting U.S. EPA Tier 3 and European Union Stage IIIa regulations. ACERT Technology reduces emissions during the combustion process by using advanced technology in the air and fuel systems, in conjunction with integrated electronics. Caterpillar meets emission regulations at the combustion source rather than recycling exhaust gases.

Record of Reliable Durability

Four Components

The building blocks of ACERT Technology are Fuel delivery Electronic control Air management After treatment onhighway only The three building blocks incorporated onto wheel tractorscraper engines are fuel delivery through EUI electronic unit injection, electronic control from the Cat ADEM A4 controller, and air management through cross flow design of the intake manifold and turbo charging. After treatment, the fourth building block or tool, is not needed on offroad applications at this time.

ACERT Technology Fuel Delivery

Multiple injection technology lowers combustion chamber temperatures. This technique optimizes thorough combustion of the fuel, reducing emissions output while giving customers more work for their fuel expense.

ACERT Technology Electronic Control

The ADEM A4 controller is a 32bit computer that uses sensors throughout the engine to regulate fuel delivery, valve timing and other engine systems. By managing load and performance, it enhances engine responsiveness and fuel economy, allows selfdiagnosis, and reduces exhaust emissions. Software offers flexibility in fuel mapping, allowing the engine to respond to specific application needs, weather and altitude conditions.

ACERT Technology Air Management

A new cross flow design in the cylinder head facilitates air movement, while tighter tolerances between the piston and cylinder liner reduces blow by gases.

Engine Features

ulli two intake and two exhaust valves per cylinder with valve rotatorslili pressure lubricated with fullflow filtered and cooled oillili drytype air cleaner with primary and secondary elementslili two fuel filters with water separator deltaP switch to monitor fuel pressurelili water cooled, center section turbocharging with wastegate and titanium wheel for high speed durabilityliul

Dual Horsepower

Cat engines have dual horsepower capability with the low power setting in torque converter drive and the high power setting in direct drive. If the auger is engaged while the machine is in torque converter drive, the machine automatically goes to the high power setting.

Mechanical Electronic Unit Injection MEUI

The MEUI system with variable shaped injection patterns provides for optimum combustion based on altitude and temperature. The Cat MEUI fuel system is a highly evolved fuel system with a proven record of reliability in the field. The system combines the technical advancement of an electronic control system with the simplicity of direct mechanically controlled unit fuel injection pressure. These features allow the C18 to completely control injection timing, duration and pressure.

Electronic Control Module

The ECM responds to operator commands and engine sensor input to optimize engine and machine performance. This advanced engine management software controls and protects the engine at all times against cold starts, high altitude operations and air filter plugging by monitoring ulli injection timing and pressure lili engine cooling fan speed lili ether starting aid lili hydraulic pumpsliul

ADEM A4 Control Module

Controls engine rpm by adjusting the fuel duration, which results in quicker starts in hot and cold weather, better fuel economy, better operator response, and automatic compensation for altitude and filter plugging.

Greater Reliability

The EUI system has fewer moving parts than mechanical unit injection and requires few adjustments. The ADEM A4 controller communicates with the monitoring system 40EMS41 to warn the operator when problems arise, preventing major damage from occurring.

Maintenance

EUI engines have virtually no mechanically controlled parts to wear or adjust. These have been replaced by electronic controls, reducing maintenance costs and increasing machine availability.

Reduced Exhaust Smoke

The ADEM A4 controller monitors electronic sensors to determine the optimum fuelair ratio. Fuel is precisely controlled during cranking, starting and acceleration to reduce smoke. The Engine Electronics are faster and more efficient than mechanically controlling the governor rack position.

Ether Starting Aid

The ADEM A4 controller activates the ether injection system during engine cranking to enhance cold weather starting.

Control Throttle Shifting CTS

Automatically synchronizes engine speed to transmission speed during shifting to reduce power train stress and increase component life. In addition it results in a smoother ride for the operator.

Directional Shift Management

Regulates engine speed to prevent damage caused by highspeed directional changes.

Low Battery Elevated Idle

The ADEM A4 controller automatically compensates for low alternator output at low idle by raising the rpm for brief intervals to keep the batteries fully charged.

Altitude Compensation

The system derates fuel delivery as a function of barometric pressure as sensed by the systems atmospheric pressure sensor. No manual adjustment is required. Auto deration prevents excessive combustion temperatures that could result in component damage.

Diagnostic Capability

Cat Electronic Technician Cat ET is used to display realtime pressures, temperatures, fuel settings and diagnostic messages as well as a historical information such as engine overspeeds, overheating, low oil pressure and air filter restriction events.

Event Log

Fuel Economy

Electronic controls optimize the timing setting for varying load conditions. The ADEM A4 controller matches timing to the load on the engine, engine rpm and temperature.

Air Filter Restriction

ADEM A4 controller monitors air filter restriction and sends a warning message to the Electronic Monitoring System 40EMS III41 to alert the operator if the restriction exceeds the allowable limit.

Scraper Electrical Harness

A ribbon wiring harness replaced the cable harness for improved wear and durability. Its greater flexibility oscillates better with machine movement, and polyurethane boots offer better protection against the elements.

Automatic Belt Tensioning

Both the tractor and scraper engines have automatic belt tensioning rather than manual tensioning. The number of belts has been reduced to two on the tractor, and two on the scraper. Fan drive bearings on both the tractor and scraper engines with ACERT technology eliminate servicing requirements.

OnePiece Power Block

The jumpstart receptacle and disconnect switch are integrated into onepiece power block that provides better electrical integrity and serviceability. The disconnect switch with lockable cover locks out all power for servicing.

NGMR Engine Cooling System

The standard radiator for the tractor is the Next Generation Modular Radiator NGMR, which features 9 fins per inch rather than 33 fins per inch found on previous models. The increased radiator fin spacing for both the tractor and the scraper reduces clogging in severe applications. Twopiece service doors improve access to clean out debris.

Scraper Radiator

The scraper has a brazed aluminum core scraper radiator with composite tanks featuring 9 fins per inch.

Extended Oil Change Interval

Oil change intervals in the C18 engine can be extended to 500 hours with the use of SOSSM analysis.

Power Train Transmission

Integrated electronics allow the machine to monitor the entire power train, reducing component stress and providing a better ride.

Transmission

Electronically controlled Caterpillar planetary powershift transmission with eight forward and one reverse speed. Tractor gears 1 2 operate in converter drive for increased torque capability during cut and fill operations. Gears 38 operate in directdrive for drive train efficiency during the haul. All scraper gears operate in converter drive for increased torque capability during the cut and fill.

Synchronized Scraper Transmission

The scraper transmission is electronically controlled by the tractor transmission, synchronizing the scraper transmission gear selection with that of the tractor transmission. The scraper transmission cannot be shifted manually. A neutralrun switch, located in the cab, allows the operator to disengage the scraper transmission.

Planetary Design

Provides larger contact area between gears than countershaft transmissions for greater loadcarrying capacity.

Transmission Hold

Incorporated into the joystick controller, Transmission Hold allows the operator to maintain converter drive for increased rimpull, or hold the current gear for enhanced control.

Programmable Top Gear Selection

Allows the operator to manually set the top gear 3rd 8th available to match conditions or to match the hauling speed of the fleet to specific jobsite needs.

Retarder

The hydraulic retarder can be used to slow the ground speed of the machine when entering the cut or fill area to allow the transmission to downshift. It also reduces service brake wear and enhances machine control.

Retarder Operation

Differential Control

Electronic differential lock helps prevent the drive wheels from spinning in poor underfoot conditions. The operator engages the differential lock with a foot control located in the cab.

Neutral Coast Inhibitor

Prevents the transmission from shifting into neutral if the operator selects neutral while moving. The transmission control will select the proper gear for the given engine rpm and ground speed.

Final Drives

Outboardmounted, planetary design final drives reduce torque loads on other power train components. Largecapacity, doublerow roller bearings and Caterpillar DuoCone seals deliver exceptional reliability in the toughest applications.

Independent Brake Systems

Expandingshoe type brakes use a camoperated design, which is airapplied and spring released. The secondary braking system uses independent front and rear circuits that are automatically applied if the service air pressure drops to 55 psi 380 kPa. Audible and visual action alert indicators inform the operator when the service air pressure drops to 75 psi 518 kPa.

Parking Brakes

The pushbutton operated parking brake features a springapplied, airreleased mechanism that operates the service brakes.

Steering

Full hydraulic power steering provides automotive feel with positive, modulated flow control for constant steering response. An optional supplemental steering system is grounddriven and provides hydraulic power for steering if needed.

Structures

Superior structural design and construction optimize performance and reliability.

Cushion Hitch

The electronically actuated cushion hitch incorporates a parallelogramtype linkage for exceptional strength. Twin nitrogen accumulators help deliver a smooth ride for enhanced operator comfort. ulli cushion hitch lock down control for positive cutting edge down pressure when loading or spreadinglili controlled oil flow dampens rebound oscillation lili leveling valve automatically centers piston in cylinder for all loads lili steel castings are used extensively to eliminate many welded joints and increase strength lili doublekingbolt design withstands high external forces and simplifies installation and removalliul

Nitrogen Accumulators

Vertically mounted hydraulic cylinder transfers road shocks to nitrogen accumulators. They absorb and dampen road shocks, thus reducing loads from being transmitted to the operator.

Lockout Switch

An operatorselectable lockout switch, located on the joystick, locks the cushion hitch for improved control of the cutting edge during loading and dumping.

Operator Station

Stateoftheart productivity and operator comfort.

MultiAdjustable Seat

The Cat Comfort Cloth Seat offers an adjustable seat and armrests for maximum operator comfort. ulli Swivels and locks in four positions 0 10 20 30 providing the optimum operating position in the cut or on the haul. lili Adjustable 4 in. 102 mm foreaft and 8 in. 203 mm vertical height to accommodate various sized operators.lili Static seat belt is standard. A retractable noncinching seat belt is available as an option.liul

Seat Suspension

The new standard seat suspension features a high performance air shock absorber with a selfcontained air compressor. For operators requiring additional damping, dual shock absorbers in the seat suspension are available.

Revised Steering Column

Increases legroom a full 3.5 in. 89 mm, and reduces knee contact.

Standard Air Conditioning

Standard air conditioning system with relocated louvers enhances airflow in the cab.

Storage And Amenities

Convenient storage location includes space for a lunch box and first aid kit. The cab also has a cup holder as well as an ashtray.

Visibility

The redesigned hood has sloped corners to maximize visibility while accommodating the low emissions engine. The redesigned hood and front shroud are wider to enclose the airtoair aftercooler ATAAC, ether starting aid, and lights. The exhaust is located at the back of the hood for good visibility to the right side.

Instrument Display Panel

Features a new quadgauge layout showing engine coolant temp, transmission torque converter oil temp, fuel level, and system air pressure.

Logical Control Placement

Placing only frequently used switches and indicator lights on the instrument panel, and less frequently used switches on the overhead console, improves efficiency and reduces reaching.

Engine Speed Lock Controller

Enhances operation during long haul cycles by allowing the operator to maintain a desired engine speed without maintaining pressure on the throttle.

Simplified Transmission Control

Simplifies gear selection 1st, 2nd, Drive and Reverse and allows operatordefined top gear control. Relocating the gear control to the rear increases operator legroom.

Neutral Lock

The neutral lock thumb control must be pressed to move the shifter from neutral. To use the top gear button, the operator must hold the yellow button until the gear display indicates the desired top gear. Releasing the yellow button sets the top gear.

Grab Handle Hand Rest

The grab handlehand rest located next to the joystick controller helps operators when adjusting seat swivel, and gives them a place to rest their hand while on the haul and return roads.

Single Lever Implement Control

Simple and easy to operate, the joystick enhances the productivity of operators of all skill levels. Requires less force to control the critical scraper functions and requires less lever travel. 1 Bowl forward back 2 Ejector side to side 3 Apron thumb rocker switch 4 Transmission Hold 5 Cushion Hitch 6 Rocker switch not shown is on front of joystick ulli Auger onofflili PushPull bail updown liul Standard open bowl does not have a rocker switch.

Electronic Controls

Integrated electronic controls provide smooth, consistent shifts through the synchronization of engine and transmission speeds.

Simplified System

The electrical system has been redesigned to utilize three electronic control modules ECM on the tractor instead of four.

Air Filter Restrictor Indicator

The ADEM A4 controller monitors air filter restriction. If the restriction exceeds the allowable limit, it alerts the operator by sending a message to the Electronic Monitoring System 40EMS III41.

Automatic Ether Injection

The ADEM A4 controller activates the ether injection system during engine cranking to enhance cold weather starting.

Automatic Altitude Compensation

At high altitudes the system automatically derates fuel delivery as a function of barometric pressure sensed by the systems atmospheric pressure sensor.

Low Battery Elevated Idle

The ADEM A4 controller automatically compensates for low alternator output at low idle by raising the rpm for brief intervals to keep the batteries fully charged.

Improved Serviceability

Combined monitoring systems, easy access diagnostics and more durable components make routine maintenance and servicing simple and fast.

Easy Access Diagnostics

A variety of diagnostic codes are accessible through the EMS main display module, via the Electronic Technician Cat ET. This offers a head start on problem solving, so with a radio call the service technician can know which tools, troubleshooting guides, and possibly even replacement parts to bring to the machine.

Greater Reliability

Maintenance

EUI engines have virtually no mechanically controlled parts to wear or adjust. These have been replaced by electronic controls, reducing maintenance costs and increasing machine availability.

Product Link

Product Link is a wireless system that allows the customer to track machine data such as location, service meter hours as well as machine health information. The system can automatically issue alerts when the machine is operated beyond ownerdefined time and location limits. Product Link is available as a factory attachment or it may be installed in the field, in that there is a mounting location for the module as well as an antenna on the machine. A wiring breakout is standard, without having to splice into existing wires.

Fuel Economy

Electronic controls optimize the timing setting for varying conditions. The ADEM A4 controller matches timing to the load on the engine, engine rpm and temperature.

Reduced Exhaust Smoke

Scraper Bowl

Designed for optimum loading, material retention and ejection.

Redesigned Bowl

The redesigned bowl minimizes falling material lodging between the bowl and the draft arm, which can result in premature wear. The modifications also provide better load retention on level ground or traversing down a grade. Bowl capacity has been increased by 3 yd3 2.3 m3, allowing more material to be moved. ulli Lowprofile bowl design offers less resistance to incoming materials.lili Cellular construction adds strength and dent resistance to bowl sides and floor.liul

Bulldozer Ejection System

Cat bulldozer ejection system offers constant spreading control with minimal material carry back. A spill guard helps retain material and keep it from spilling over onto the rear of the scraper optional on single engine open bowl scrapers.

Cutting Edges

May be adjusted according to job conditions. The stinger drop down position provides good penetration and efficient flow of material into the bowl, whereas the level cutting edge is used for finish work or very high impact conditions.

Ground Engaging Tools

A wide variety of Cat Ground Engaging Tools GET options such as standard, serrated, and abrasion resistant material ARM, are available to optimize scraper loading in various materials. For example, ARM scraper cutting edges and router bits will provide up to five times the wear life of conventional edges and router bits in high wear, low impact applications. Depending on applications, the serrated cutting edge may be more cost effective than the integrated tooth cutting edge.

Level Cutting Edge

Used for finish work or for very high impact conditions where stinger breakage has been a problem Standard Cutting Edges Center, End Router Bits

Teeth and Adapters

Improve penetration into compacted material. The bolton adapters are available for all scrapers.

Material Application

Well suited to handle a wide variety of material from clay to shot rock.

PushLoading

To achieve maximum productivity, the 631G should be push loaded by a D9R or D10R TrackType Tractor. The larger tractor offers quicker loading times with denser loads than the smaller tractor.

Auger Arrangement

Excellent selfloading capability in a wide range of material.

Versatility

The auger has a wide material appetite ranging from rock to free flowing material such as sand.

Auger Mechanism

The auger lifts material off of the cutting edge, conditions it and carries it to the top of the load for true selfloading capability. Material is distributed evenly throughout the bowl, resulting in consistent loads.

Material Handling

The auger actions on the material produce several benefits ulli wide material appetite, ideal for landfills lili blends the material to help eliminate voids in the bowl for consistent payloads lili conditions material for precise metering and better compaction in the filllili reduces dust and noise during loadingliul

Slip Limiter Switch

Prevents rear wheel spin during loading.

Hydraulic System

Single hydraulic system for entire machine with separate implement pumpsvalves simplifies maintenance and improves reliability.

Implement Valve Relocation

The implement valve has been relocated from the tractor to the top of scraper draft tube. The result is fewer hoses and tubes that cross over the gooseneck, and fewer potential leak points. The relocation also improved access to the implement valve for better serviceability.

Fullflow Circuits

The hydraulic system features closedloop, fullflow hydraulic circuits powered by geartype and pistontype pumps.

Apron

Prevents material spillage and retains fine material far better than an elevating scraper.

Serviceability

Count on Caterpillar for simplified service and the most productive uptime.

Grouped Service Points

Maintenance and service points for the engine are grouped on the righthand side for easy access. They include the engine air cleaner, engine oil check and fill, fuel filters and priming, coolant level sight glass, window washer bottle, air conditioning dryer cartridge, ether starting aid canister, engine oil filter, fan drive lubrication, and sampling ports for the engine oil and coolant. ulli Spinon fluid filters for all but the main hydraulic filter lili Cab wiring harness redesigned and relocated for better serviceabilityliul

TwoPiece Service Doors

The tractor has a standard twopiece door on the right side, which allows better access to service points. The hood is hinged on the front and has spring struts, so the hood easily swings open towards the front of the machine. This allows better access to those areas located on top of the engine.

ElectroHydraulic Implement Control

Simplifies serviceability by removing the cab pilot valve and associated lines, which also improves reliability and reduces noise. The high efficiency oil filter provides cleaner oil for the pilot system.

Electronic Technician

The Caterpillar Electronic Technician Cat ET Service Tool is useful in troubleshooting existing problems or identifying potential problems by displaying ulli Realtime pressures, temperatures, fuel settings and diagnostic messages lili Historical data such as engine overspeeds, overheating, low oil pressure and air filter restriction eventslili More detailed information to the service technician who can access Cat ET via a laptop computerliul

Easy Access Diagnostics

Customer Support

Cat dealer services help you operate longer with lower costs.

Product Support

You will find nearly all parts at our dealer parts counter. Cat dealers use a worldwide computer network to find instock parts to minimize machine down time. To save money use genuine Cat Reman parts whenever possible. You receive the same warranty and reliability as new products at substantial cost savings.

Machine Selection

Make detailed comparisons of the machines under consideration before purchase. Cat dealers can estimate component life, preventive maintenance cost, and the true cost of lost production.

Purchase

Look past initial price. Consider the financing options available as well as daytoday operating costs. Look at dealer services that can be included in the cost of the machine to yield lower equipment owning and operating costs over the long run.

Customer Support Agreements

Cat dealers offer a variety of product support agreements, and work with customers to develop a plan that best meets specific needs. These plans can cover the entire machine, including attachments, to help protect your investment.

Operation

Improving operating techniques can boost your profits. Your Cat dealer has videotapes, literature and other ideas to help you increase productivity, and Caterpillar offers certified operator training classes to help maximize the return on your machine investment.

Maintenance Services

Talk to your dealer about the range of available maintenance services. Repair option programs guarantee the cost of repairs up front. Diagnostic programs such as SOSSM Analysis and Coolant Sampling and Technical Analysis help avoid unscheduled repairs.

Replacement

Repair, rebuild or replace Your Cat dealer can help you evaluate the cost involved so you can make the right choice.

Scraper Bowl
Capacity Heaped	34 yd3
Rated Load	82200 lb
Capacity Struck	24 yd3
Depth of Cut - max.	17.2 in
Width of Cut, to Router Bits	138.3 in
Ground Clearance - max.	21.5 in
Cutting Edge - thickness	1.12 in.
Hyd. Penetration Force - 631G	57375 lb
Depth of Spread - max.	18.9 in
Apron Opening	79 in
Apron Closure Force	38250 lb
Transmission
Travel Speed Maximum	33.2 mph
1 Forward	2.9 mph
2 Forward	5.2 mph
3 Forward	7.4 mph
4 Forward	10 mph
5 Forward	13.4 mph
6 Forward	18.2 mph
7 Forward	24.5 mph
8 Forward	33.2 mph
Reverse	6.2 mph
Tractor Engine
Net Power - Tractor/Scraper	345 kW (462 hp)
Net Power	345/373 kW 462/500 hp
Gross Power - Gears 1-2	488 hp
Gross Power - Gears 3-8	526 hp
Net Power - Gears 1-2	462 hp
Net Power - Gears 3-8	500 hp
Bore	5.7 in
Stroke	7.2 in
Displacement	1105 in3
Weights
Operating Weight	102459.71 lb
Weights - Standard, tandem
Total Shipping	100005.97 lb
Total Operating - empty	102459.71 lb
Front Axle	68647.46 lb
Rear Axle	33812.26 lb
Total Operating - loaded	184658.97 lb
Front Axle Weight - loaded	97869.7 lb
Rear Axle Weight - loaded	86789.28 lb
Dimensions
Width - overall machine	155 in
Width - tractor	137 in
Width - rear tire center lines	97 in
Width - inside of bowl	134 in
Width - outside rear tires	143.2 in
Height - overall shipping	168.8 in
Height - top of cab	146.3 in
Ground Clearance, Tractor	26.2 in
Front of Tractor to Front Axle	132.2 in
Axle to Vertical Hitch Pin	21.6 in
Height - scraper blade max.	21.5 in
Wheelbase	345.2 in
Length - overall machine	573.4 in
Rear Axle to Rear of Machine	95.97 in
Steering
Width - 180° Turn	40.02 ft
Steering Angle - right	90°
Steering Angle - left	85°
Service Refill Capacities - Tractor
Crankcase	11.9 gal
Fuel Tank - 631G	215.04 gal
Transmission	29 gal
Differential	39 gal
Final Drive (per side)	6.1 gal
Cooling System	29 gal
Hydraulic Reservoir	50.2 gal
Wheel Coolant (each)	19.8 gal
Windshield Washer	1.5 gal
Hydraulics
Bowl Cylinder Bore	7.2 in
Bowl Cylinder Stoke	34.4 in
Apron Cylinder Bore	8.2 in
Apron Cylinder Stroke	28.6 in
Ejector Cylinder Bore	8.2 in
Ejector Cylinder Stroke	74 in
Steering Circuit	100 gal/min
Scraper Circuit	91 gal/min
Cushion Hitch Circuit	9 gal/min
Secondary Steering Circuit	100 gal/min
Relief Valve - Steering Circuit	1987 psi
Relief Valve - Implement Circuit	2030 psi
Compensator Setting - Cushion Hitch Circuit	2320 psi
Service Refill Capacities - Scraper
Wheel Coolant (each)	19.8 gal
Transmission - 631G
1 Forward	2.9 mph
2 Forward	5.2 mph
3 Forward	7.4 mph
4 Forward	10 mph
5 Forward	13.4 mph
6 Forward	18.2 mph
7 Forward	24.5 mph
8 Forward	33.2 mph
Reverse	6.2 mph