Cat® 3408E Tractor Engine 631G 637GNet Power

Gears 1-2 336 kW/450 hp 336 kW/450 hpGears 3-8 365 kW/490 hp 365 kW/490 hp

Gross PowerGears 1-2 358 kW/480 hp 358 kW/480 hpGears 3-8 384 kW/515 hp 384 kW/515 hp

Cat® 3306 Scraper Engine – 186 kW/250 hp

631G,637GWheel Tractor-Scrapers

®

2

Power Train FeaturesThe power train features an integratedelectronic control system whichprovides continuous communicationbetween the engine, transmission, andoperator. pg. 7

631G and 637G Tractor-ScrapersHighly productive earthmoving machines, built to last.

Operator StationStandard enclosed ROPS which featuresa redesigned cab interior that deliversenhanced operator comfort, efficiency,and productivity. Features includestandard air-conditioning, greaterlegroom, a single lever joystick control,and a redesigned control layout.pg. 4

Scraper BowlCellular construction which features awide cutting edge and a low profiledesign to optimize loads. pg. 11

Electronic ControlsThe electronic controls respond tooperator commands and input from on-board sensors to optimize machineperformance. In addition, the electroniccontrols provide advanced diagnosticcapabilities that result in better machineavailability. pg. 6

Auger ArrangementProvides self-loading capability with aCaterpillar® designed and manufacturedauger system. pg. 12

Quick loading, high travel speeds and the ability to load anddump on the run yield fast cycle times, allowing CaterpillarWheel Tractor-Scrapers to consistently deliver highproductivity at the lowest cost per ton.

✔

3

TransmissionCaterpillar planetary powershifttransmission design offers greater loadcarrying capacity than competitivedesigns by providing a larger contactarea between gears. Individual clutchmodulation provides fast, smooth shiftsand improved serviceability. pg. 9

Electronically Controlled Cushion HitchAccumulator system dampens roadshocks, and helps prevent loping, andlock down for precise control.pg. 14

Advanced Modular Cooling System(AMOCS)Caterpillar exclusive technologyimproves serviceability and coolingcapability. pg. 10

ServiceabilitySimplified service means moreproductive uptime. pg. 15

Power TrainCaterpillar 3408E engine, with theHEUI™ fuel system that uses hydraulicelectronic unit injectors, and eight-speed power shift transmission combineto form a responsive, highly fuelefficient power train. pg. 8

Push-Pull Arrangement (637G)Designed for maximum productivitywhile providing the flexibility for self-loading, push-pull loading or standardpush loading. pg. 13

✔

✔ New feature

4

Operator StationHas been redesigned for enhanced operator comfort, efficiency, and productivity.

5

Legroom. A new design increaseslegroom 11%, a full 88.9 mm andeliminates knee contact points.

Standard Enclosed ROPS. Standardenclosed ROPS with air conditioningenhances operator comfort as well asefficiency.

Multi-Adjustable Seat. The Cat®

Comfort Cloth Seat offers comfort withmulti-adjustable seat and armrests.■ Swivels and locks in four positions

(0˚ to 30˚) providing the optimumoperating position in the cut or on thehaul.

■ Fore/aft and vertical heightadjustment to accommodate varioussized operators.

Seat Suspension. The new standard seatsuspension redefines the ride ofscrapers. It features a self contained aircompressor with a high performance airshock absorber.

Joystick Controller. Simple and easy tooperate, the joystick enhances theproductivity of operators of all skilllevels. Requires less force to control thecritical scraper functions and requiresless lever travel.

1 Bowl (forward & back)

2 Ejector (side to side)

3 Apron (thumb rocker switch)

4 Transmission Hold

5 Cushion Hitch

Trigger* (not shown - is on front ofjoystick)■ Auger (on/off)■ 637G only: Push-Pull

(bail up/down)

* Standard open bowl does not have a trigger.

14

5

3

(Down)

1 (Up)

2 (Forward) 2 (Return)

Instrument Display Panel.Instrumentation has been relocated for optimal viewing. Real-timeperformance and diagnostic informationis provided through the display panel.

Electronic Monitoring System (EMS).Monitors the machine status andprovides real-time informationincluding warnings of problemsidentified by the EMS.

Ergonomic Switch Layout. Enhancesconvenience by placing the frequentlyused switches and indicator lights onthe instrument panel, and lessfrequently used switches on theoverhead console.

Throttle Lock Controller. Enhancesoperation during long haul cycles byallowing the operator to maintain adesired engine speed withoutmaintaining pressure on the throttle.

Standard Air Conditioning. Standard airconditioning system with improvedventilation location enhances airflow inthe cab.

Storage And Amenities. Convenientstorage location includes space for alunch box and first aid kit. The cab alsohas a cup holder as well as an ashtray.

Visibility. The redesigned hood hassloped corners to maintain visibility.The exhaust has been moved to the backof the hood to increase visibility to theright side.

(Forward) (Return)

(Down)

(Up)

6

Reduced Exhaust Smoke. Utilizingelectronic sensors, the optimum air/fuelratio is precisely controlled by theelectronic control module during allsegments of the haul cycle. This resultsin a reduction of smoke and particulatesduring cranking, starting, andacceleration.

Low Battery Elevated Idle. Electroniccontrol module automaticallycompensates for low alternator output atlow idle to keep the batteries fullycharged.

Electronic ControlsThe electronic controls respond to operator commands and input from on-board sensors tooptimize machine performance. In addition, the electronic controls provide advanceddiagnostic capabilities that result in better machine availability.

Air Filter Restrictor Indicator.Electronic control module monitors airfilter restriction and sends a warningmessage to the electronic monitoringsystem to alert the operator if therestriction exceeds the allowable limit.

Automatic Ether Injection. Electroniccontrol module activates the etherinjection system during engine crankingto enhance cold weather starting.

Automatic Altitude Compensation.At high altitudes the system auto-matically de-rates fuel delivery as a function of barometric pressure sensedby the system’s atmospheric pressuresensor.

Easy Access Diagnostics. ElectronicTechnician displays real-time pressures,temperatures, fuel settings anddiagnostic messages as well ashistorical information such as engineover-speeds, overheating, low oilpressure, and air filter restriction events.

Fuel Economy. Electronic controls yielda fuel savings by optimizing the timingsetting for varying conditions.

Greater Reliability. Caterpillar’sHEUI™ fuel system uses hydraulicelectronic unit injectors, has fewermoving parts than mechanical unitinjection, and requires few adjustments.

Maintenance. With fewer mechanicallycontrolled parts to wear or adjust, theelectronic controls reduce maintenancecosts and increase machine availability.

7

Power Train FeaturesElectronic controls have been integrated into the power train to provide optimal powerdelivery, expanded monitoring capabilities, more efficient fuel usage, and reduced emissions.

Integrated Electronics. Electronic controlsintegrated into the power train monitors theengine, transmission, and operator input.■ Electronic control provides smooth,

consistent shifts through thesynchronization of engine andtransmission speeds.

■ Planetary design provides larger contactarea between gears than countershafttransmissions for greater load-carryingcapacity.

Controlled Throttle Shifting. Automaticallysynchronizes engine speed to transmissionspeed during shifting to reduce power trainstress, increase component life, andprovide a smoother ride for the operator.

Programmable Top Gear Selection.Top gear selection may be either selectedby the operator or downloaded into theMAC-14 controller. Provides theflexibility to match the hauling speed of the fleet to specific job-site needs.

Differential Control. Electronicdifferential lock on the tractor helpsprevent the drive wheels fromspinning in poor underfoot conditions.The operator engages the differentiallock, prior to wheelspin, with eitherthe left or right foot controls locatedon the floor of the cab.

Transmission Hold. Allows theoperator to maintain the current gearfor enhanced control.

Neutral Coast Inhibitor. Prevents thetransmission from shifting into neutralif the operator selects neutral whilemoving faster than 8 kmph. Maintainsoil to transmission to prevent damage.

Directional Shift Management.Reduces driveline torque andtransmission clutch energy whendirectional shifts are attempted whilethe engine is at high rpms.

Final Drives. Outboard-mounted,planetary design final drives reducetorque loads on other drivetraincomponents while deliveringexceptional reliability in the toughestapplications.

Braking System. Provides cam-operated expanding-shoe type brakes,independent front and rear circuits,low air pressure audible and visualaction alert indicators, and a push-button operated parking brake.

8

Power TrainProven components combine to deliver the most durable, reliable power train in the industry,keeping cost low and production high.

3408E Tractor Engine. The engine hasthe HEUI™ fuel system which useshydraulically actuated electronicallycontrolled unit injectors. The 3408Ediesel engine has dual horsepowercapability for the tractor, and providesthe power and torque rise for excellentlugging in tough loading conditions.

637G only:3306 Scraper Engine. Powered by the3306 direct-injection diesel engine ratedat 250 hp (186 kW). Automaticvariable-injection timing delivers fuelas needed when engine speed variesbetween cut or fill work, and duringhigh-speed hauling for maximumefficiency.

Dual Horsepower Capability. The electronic engine provides dualhorsepower settings, which increaseshorsepower and provides quickeracceleration on the haul road.

HEUI™ Fuel System. Yields improvedfuel economy through more precise fueldelivery and cleaner, more efficientcombustion.

Advanced Diesel Engine Management(ADEM) . Utilizes advanced enginemanagement software to monitor,control and protect the engine.

Air To Air After Cooling (ATAAC).Reduces air inlet temperature forenhanced combustion efficiency,reduced emission levels, higher altitudecapability, and more power.

9

TransmissionIntegrated electronics allows the machine to monitor the power train which reduces stress aswell as provide a better ride to the operator.

Tractor Transmission. The electronically controlled Caterpillarplanetary powershift transmission usesproven components electronicallyintegrated to achieve new levels ofperformance and efficiency.■ Eight forward and one reverse speed. ■ Gears one and two operate in

converter drive for increased torquecapability during cut and filloperations.

■ Gears three through eight operate indirect-drive for drivetrain efficiencyduring the haul and return.

■ Reverse gear operates in converterdrive.

Retarder. Reduces wear on the servicebrakes and enhances machine control.The hydraulic retarder is internal to thepower train and acts as an internal brakewhen going down a grade. It is engagedbefore going down a grade.

637G only:Scraper Transmission. Electronicallycontrolled Caterpillar planetarypowershift transmission.■ Four forward and one reverse speed.■ All gears operate in converter drive

for increased torque capability. ■ The scraper transmission is

electronically controlled by thetractor transmission and issynchronized to match the tractortransmission gear selection.

10

Advanced Modular Cooling System (AMOCS)Caterpillar exclusive technology improves serviceability and cooling capability.

Increased Performance. Dual stagecoolant flow process improves coolingcapability by allowing coolant to passon the air side of the radiator as well asthe fan side. The coolant travels:■ Into the air side of the bottom tank;■ Up the air side of the core;■ Down the fan side of the core;■ To the fan side of the bottom tank;■ Then back to the engine.

Basic Construction. A modular designradiator that is less prone to pluggingdue to a lower fin density of nine finsper inch versus thirty-three of theprevious folded core radiator.

Improved Serviceability. Modulardesign allows one module to bereplaced instead of replacing the entireradiator. ■ Shunt tank incorporates a sight gauge

for quick, accurate checks of coolantlevel.

■ No longer necessary to remove thetop tank to swap out modules.

■ Unique service tool facilitates coreremoval and allows one-personservice job.

■ Shunt tank incorporates a sight gaugefor quick, accurate checks of coolantlevel.

11

Scraper BowlDesigned for optimum loading, material retention and ejection.

Low-profile Design. Offers lessresistance to incoming materials.

Cat Bulldozer Ejection. Systemcombines constant spreading controlwhile minimizing carryback material.

Overflow Guard. Helps retain materialand keep it from spilling over onto therear of the scraper.

Cellular Construction. Adds strengthand dent resistance to bowl sides andfloor.

Caterpillar Ground Engaging Tools(G.E.T.). To optimize scraper loading invarious materials a wide range ofG.E.T. are available.

Cutting Edge. May be adjustedaccording to job conditions. The stinger(drop down) position provides goodpenetration and efficient flow ofmaterial into the bowl while the levelcutting edge is used for finish work. Forefficient loading the thinnest edge thatprovides satisfactory wear life should beused.

12

Auger ArrangementExcellent self-loading capability in a wide range of material.

Material Application. Work alonecapability with a wide material appetiteranging from overburden to laminatedrock. Conditions material whichpromotes compaction in the fill andsignificantly reduces dust duringloading.

Dual Horsepower. Provides increasedpower to the auger for improvedloading performance.

Auger Mechanism. The auger liftsmaterial off of the cutting edge for trueself-loading capability. Material isdistributed evenly throughout the bowl,resulting in consistent loads.

Apron. Prevents material spillage andretains fine material far better than anelevating scraper.

Additional Auger Features. Caterpillardesign provides top performance.■ Two-speed auger motor shifts

automatically from high speed to lowspeed to enhance loading capability.

■ Dual horsepower tractor engineautomatically reverts to the highersetting when the auger motor isengaged.

■ Single hydraulic system for entiremachine with separate implementpumps and valves.

■ Scraper slip limiter switch preventsrear wheel spin during loading.

13

Push-Pull Arrangement (637G only)Wide material appetite with high production capability.

Material Application. Well suited tohandle a wide variety of material fromclay to shot rock.

Push-Loading. Working together, push-pull scrapers combine to place over1400 horsepower on a single cuttingedge. Fast loading means quicker cycletimes.

Tandem Engine. Provides the ability tohandle steep grades as well as all wheeldrive to handle soft, slippery underfootconditions.

Dual Horsepower. Provides increasedhorsepower during the haul whichresults in faster cycle times.

Push-Pull Attachment. Optional push-pull arrangement concentrates thecombined horsepower of two machinesonto one cutting edge. The push-pullattachment allows two individualmachines to act as a self-loadingmachine. Typically both of the push-pull machines can load in less than aminute.

14

Electronically Controlled Cushion HitchDelivers a smoother ride for enhanced operator comfort.

Cushion Hitch. Electrically actuatedhydraulic damper absorbs haul roadshocks for increased operator comfort.

Cushion Hitch Features. Designed forprecise control.■ Can be locked down when loading or

spreading.■ Vertically mounted hydraulic cylinder

transfers road shocks to nitrogenaccumulators.

■ Controlled oil flow dampens reboundoscillation.

■ Leveling valve automatically centerspiston in cylinder for all loads.

■ Extensive use of steel castingseliminates many welded joints andincreases strength.

■ Double-kingbolt design withstandshigh external forces and enhancesinstallation and removal.

Steering. Full hydraulic power steeringprovides automotive feel with positive,modulated flow control for constantsteering response.

15

ServiceabilitySimplified service means more productive uptime.

Service Points. Service points for theengine are grouped on the right-hand-side for easy access.

Floor Rollers. Sealed floor rollerseliminate lubrication.

Electro-Hydraulic Control. Simplifiesserviceability by removing the cab pilotvalve and associated line from the cab,which provides increased cab space andreduces noise. The high efficiencyelectro-hydraulic pilot oil filter providescleaner oil for the pilot system.

Wiring Harness. Incorporates color-coded and numbered circuits for quickidentification and simplifiedtroubleshooting.

Cantilever Wheels. Provide greaterparts commonality and ease ofserviceability to the wheels and brakes.

Electronic Monitoring System (EMS).Monitors the machine status andprovides real-time information to theoperator including warnings ofproblems identified by the ElectronicControl Modules.

Convenient Diagnostic Connections.Allow quick trouble-shooting using theElectronic Technician (ET) service tool.

16 631G and 637G Tractor-Scrapers specifications1616

Tractor Engine (631G/637G)

Engine Model* 3408E

Net Power - Gears 1-2 336 kW/450 hp

Net Power - Gears 3-8 365 kW/490 hp

ISO 9249 365 kW/490 hp

EEC 80/1269 365 kW/490 hp

Gross Power - Gears 1-2 358 kW/480 hp

Gross Power - Gears 3-8 384 kW/515 hp

Bore 137 mm

Stroke 152 mm

Displacement 18 Liters

* Ratings at 2000 rpm

Scraper Engine (637G only)

Engine Model* 3306

Net Power 186 kW/250 hp

ISO 9249 186 kW/250 hp

EEC 80/1269 186 kW/250 hp

Gross Power 201 kW/270 hp

Bore 121 mm

Stroke 152 mm

Displacement 10.5 Liters

* Ratings at 2200 rpm

Scraper Bowl

631G 637GMaximum depth of cut 437 mm 437 mm

Width of cut, outside router bits 3512 mm 3512 mm

Maximum rated load 34 020 kg 34 020 kg

Heaped, SAE rating 23.7 m3 23.7 m3

Struck, SAE rating 16.1 m3 16.1 m3

Maximum ground clearance 545 mm 545 mm

Thickness of optional cutting edge 42 mm 42

Maximum hydraulic penetration force 255 kN 360 kN

Maximum depth of spread 480 mm 480 mm

Apron opening 2007 mm 2007 mm

Apron closure force 170 kN 170 kN

BrakesMeet the following standard: ISO 3450: 1998.

Secondary brake features■ uses single axle service brakes which

are air-applied, spring-released■ automatically applied if service air

pressure drops to 380 kPa■ audible and visual action alert

indicators inform operator whenservice air pressure drops to 518 kPa

Service brake features■ air-applied, spring-released■ cam-operated, expanding-shoe type

Parking brake features■ uses service brakes which are spring-

applied, air-released■ manually applied park brake switch

can be applied with button on dash

Service Refill Capacities

631G 637G 637GTractor Tractor Scraper

Liter Liter Liter

Fuel tank 814 1268 –

Crankcase 45 45 27

Transmission 127 127 49

Differential 136 136 17

Final drive, each side 25 25 22

Cooling system 122 126 76

Hydraulic reservoir 190 190 –

Wheel coolant, each 75 75 75

Windshield washer 1.5 1.5 –

17631G and 637G Tractor-Scrapers specifications

Hydraulics

631G 637GBowl cylinder

bore 184 mm 184 mm

stroke 813 mm 813 mm

Apron cylinder

bore 210 mm 210 mm

stroke 727 mm 727 mm

Ejector cylinder

bore 210 mm 210 mm

stroke 1880 mm 1880 mm

Steering circuit 389 liter/min 389 liter/min

Scraper circuit 344 liter/m 344 liter/min

Cushion hitch circuit 34.5 liter/min 34.5 liter/min

Optional supplemental steering circuit 291 liter/min 291 liter/min

Relief valve settings

Steering circuit 13 700 kPa 13 700 kPa

Implement circuit 14 000 kPa 14 000 kPa

Compensator settings

Cushion hitch circuit 16 000 kPa 16 000 kPa

Transmission

631G 637GForward km/h km/h

1 4.7 5.5

2 8.4 10.0

3 11.9 12.2

4 16.1 16.6

5 21.6 22.2

6 29.3 30.1

7 39.4 40.6

8 53.5 54.9

Reverse 9.9 9.9

SteeringWidth Required for Curb-to-Curb 180 Degree Turn 12.2 m

Steering Angle

Right 90 Degrees

Left 85 Degrees

Hydraulic Output* 370 L/min

Ground-Driven Secondary Steering System* 192 L/min

* Ratings at 2000 rpm Weights(approximate)

631G 637G 637GStandard Standard Push-pull

Shipping

Tractor 20 866 kg 20 458 kg 22 024 kg

Scraper 24 496 kg 30 689 kg 30 665 kg

Total 45 362 kg 51 147 kg 52 689 kgOperating empty,

Front axle 31 138 kg 30 708 kg 32 690 kg

Rear axle 15 337 kg 21 339 kg 20 900 kg

Total 46 475 kg 52 047 kg 53 590 kgLoaded

Front axle 42 662 kg 42 173 kg 43 805 kg

Rear axle 37 833 kg 43 894 kg 43 805 kg

Total 80 495 kg 86 067 kg 87 610 kg

CabCaterpillar cab and Rollover ProtectiveStructure (ROPS) are standard in NorthAmerica, Europe and Japan.

FeaturesThe operator sound pressure level isless than 83 dB(A) when measured perISO 6394 or 86/662/EEC, with cabdoors and windows closed.■ ROPS meets the following criteria:

ISO 3471-1986, ISO 3471-1994■ also meets the following criteria for

Falling Objects Protective Structure:ISO 3449-1992

■ standard airconditioning systemcontains R134A refrigerant.

18 631G and 637G Tractor-Scrapers specifications

To determine gradeability performance:Read from gross weight down to thepercent of total resistance. Totalresistance equals actual percent gradeplus 1% for each 9 kg/t of rollingresistance. From this weight-resistancepoint, read horizontally to the curvewith the highest obtainable gear, thendown to maximum speed. Usablerimpull will depend upon tractionavailable and weight on drive wheels.

Gradeability/Speed/Rimpull

0 5 10 15 20 25 30 35 40 45 50 55

6555

45

35

25

20

15

10

8

6

4

2

1

kg x1000

km/h

30%

25%

20%

15%

12%

10%

8%

6%

5%

4%

3%

2%

605040302015 70 90 kg x 1000

E L

1

2

3

45

6

7

8

631GGross Weight37.25-35 Tires

Speed

E – Empty 46 475 kgL – Loaded 80 495 kg

Rim

pull

Tota

l Res

ista

nce

(Gra

de p

lus

Rolli

ng R

esis

tanc

e)

1 – 1st Gear Torque Converter Drive2 – 2nd Gear Torque Converter Drive3 – 3rd Gear Direct Drive4 – 4th Gear Direct Drive5 – 5th Gear Direct Drive6 – 6th Gear Direct Drive7 – 7th Gear Direct Drive8 – 8th Gear Direct Drive

0 5 10 15 20 25 30 35 40 45 50 55

6555

45

35

25

20

15

10

8

6

4

2

1

kg x1000

km/h

30%

25%

20%

15%

12%

10%

8%

6%

5%

4%

3%

2%

605040302015 70 90 kg x 1000

1

2

3

4

56

7

8

E L

637GGross Weight37.25-35 Tires

Speed

E – Empty 52 047 kgL – Loaded 86 067 kg

Rim

pull

Tota

l Res

ista

nce

(Gra

de p

lus

Rolli

ng R

esis

tanc

e)

19631G and 637G Tractor-Scrapers specifications

To determine retarding performance:Read from gross weight down to thepercent effective grade. Effective gradeequals actual percent grade minus 1%for each 9 kg/t of rolling resistance.From this weight-effective grade point,read horizontally to the curve with thehighest obtainable speed range, thendown to maximum descent speed theretarder can properly handle.

Retarding

km/h0 5 10 15 20 25 30 35 40 45 50 55

E L3

4

5

6

7

8

30 kg x 100040 50 60 70 80

30%

22%

16%

10%

5%

1%

631GGross Weight

Speed

E – Empty 46 475 kgL – Loaded 80 495 kg

Effe

ctiv

e G

rade

(Gra

de m

inus

Rol

ling

Resi

stan

ce)

3 – 3rd Gear Direct Drive4 – 4th Gear Direct Drive5 – 5th Gear Direct Drive6 – 6th Gear Direct Drive7 – 7th Gear Direct Drive8 – 8th Gear Direct Drive

km/h0 5 10 15 20 25 30 35 40 45 50 55 60

E L

34

56

7 8

35 kg x 100055 75 95 115 135

30%

25%

20%

15%

10%

1%

5%

637GGross Weight

Speed

E – Empty 52 047 kgL – Loaded 86 067 kg

Effe

ctiv

e G

rade

(Gra

de m

inus

Rol

ling

Resi

stan

ce)

20 631G and 637G Tractor-Scrapers specifications

631G1 Overall machine width 3938 mm

2 Tractor width 3481 mm

3 Width to center of rear tires 2464 mm

4 Width to inside of bowl 3405 mm

5 Width to outside of tires 3636 mm

6 Overall shipping height 4286 mm

7 Height to top of cab 3715 mm

8 Tractor gound clearance 665 mm

9 Length from front axle to front 3359 mm

10 Axle to vertical hitch pin 548 mm

11 Maximum scraper blade height 545 mm

12 Wheelbase 8769 mm

13 Overall machine length 14 565 mm

14 Length from rear axle to rear 2437 mm

Dimensions 631GAll dimensions are approximate.

21 53

76

9

11

12 14

13

8

10

4

21631G and 637G Tractor-Scrapers specifications

637G1 Overall machine width 3938 mm

2 Tractor width 3481 mm

3 Width to center of rear tires 2464 mm

4 Width to inside of bowl 3405 mm

5 Width to outside of tires 3636 mm

6 Overall shipping height 4286 mm

7 Height to top of cab 3715 mm

8 Tractor gound clearance 665 mm

9 Length from front axle to front 3359 mm

10 Axle to vertical hitch pin 548 mm

11 Maximum scraper blade height 545 mm

12 Wheelbase 8769 mm

13 Overall machine length 14 565 mm

14 Length from rear axle to rear 2437 mm

15 Maximum bail length (637G only) 4960 mm

16 Extended push block (637G only) 2744 mm

Dimensions 637GAll dimensions are approximate.

12 3 4 5

67

15 9 12

10

14

8

13

11

16

22 631G and 637G Tractor-Scrapers specifications

Standard EquipmentStandard equipment may vary. Consult your Caterpillar dealer for specifics.

ElectricalAlarm, BackupAlternator, 75 amp - Tractor EngineAlternator, 35 amp - Scraper Engine

(637G only)Batteries (4), 12V Maintenance Free,

High Output Batteries (2), 12V Maintenance Free,

High Output (637G only)Electrical System , 24V Lighting System - (directional signals,

hazard lights, halogen headlights withdimmer, cutting edge floodlight)

Starting ReceptacleOperator EnvironmentAir Conditioner (includes heater and

defroster)Cigarette Lighter and AshtrayCoat HookDiagnostic Connection Port (12V)Dome Courtesy LightGauge Group

Actual Transmission Gear IndicatorCoolant TemperatureElectronic Monitoring System

(EMS II)Fuel Gauge SpeedometerSystem Air PressureTachometerTransmission/Torque Converter Oil

TemperatureHornJoystick ControlRadio Ready (two radio openings,

speakers, and 5-amp converter)Rearview MirrorsROPS Cab - Sound Suppression and

PressurizationStatic Seatbelt – Seat Mounted

Seat, Cloth with Air SuspensionSteering Wheel – Tilt and TelescopingStorage CompartmentThrottle LockTransmission HoldWindows – Sliding SideWindshield – Laminated GlassWindshield Wiper/Washer – Front and

Rear

Power TrainTractor

3408E Diesel EngineGuard, CrankcaseHEUI™ Fuel System8-Speed Automatic Powershift

TransmissionControl Throttle ShiftingDifferential-LockupDownshift InhibitorNeutral Coast InhibitorProgrammable Top-Gear SelectionRetarder, Hydraulic

Scraper (637G only)3306 Diesel EngineDirect Injection Turbocharged

Aftercooled (DITA)4-Speed Automatic Poweshift

TransmissionRetarder, Hydraulic

Power Train - Common FeaturesAir Cleaner, Dry Type with Pre-cleanerBraking System

Parking / Primary / SecondaryShields - Brake

Electric Start, 24VFan, SuctionGround Level Engine ShutdownMufflerStarting Aid, Ether

631GOther Standard EquipmentAdvanced Modular Cooling System

(AMOCS) RadiatorAir DryerEngine Door, Right SideExtended Life Coolant, -36°CFast Oil ChangeFenders, TractorProduct Link ReadyTires, 37.25-R35 Radial E3Tow PinsThermo-Shield, Laminated

637GOther Standard EquipmentTractor and Scraper

Extended Life Coolant, -36°CFendersTires, 37.25-R35 Radial E3Tow PinsFast Oil Change

TractorAir DryerAdvanced Modular Cooling System

(AMOCS) RadiatorEngine Door, Right SideProduct Link ReadyThermo-Shield, Laminated

ScraperFast Fill System

23631G and 637G Tractor-Scrapers specifications

Optional EquipmentOptional equipment may vary. Consult your Caterpillar dealer for specifics.

631GTractorCoolant, Extended Life -50°CCooler, Hydraulic OilGuard, Crankcase Heavy DutyGuard, Power TrainHeater, Engine Coolant, 120 VLights, Side VisionRear Auxiliary Defrost FanRetarder, HydraulicSeat Belt, RetractableSecondary Steering

Special ArrangementsStandard Bowl with Auger

ScraperGuard, OverflowFast Fuel SystemFendersLiner, Bowl

637GTractorCoolant, Extended Life -50°CGuard, Crankcase Heavy DutyGuard, Power TrainHeater, Engine Coolant, 120 VLights, Side VisionRear Auxiliary Defrost FanSeat Belt, RetractableSecondary Steering

Special ArrangementsPush-PullStandard Bowl with AugerCoal BowlCoal Bowl with Auger

ScraperAlternator, 100 ampAlternator, 75 ampBatteries, Heavy DutyCoolant, Extended Life -50CHeater, Engine Coolant, 120 VLiner, BowlMulti Row Radiator

631G and 637G Tractor-Scrapers

HEHM2718 (09/2001) hr

www.CAT.com

© 2001 Caterpillar

Materials and specifications are subject to change without notice.Featured machines in photos may include additional equipment.

See your Caterpillar dealer for available options.

®