®®

EngineEngine Model Cat® 3412E dieselGross Power 503 kW 675 hpFlywheel Power 463 kW 620 hp

WeightsOperating Weight 70 815 kg 156,120 lb

Operating SpecificationsBlade Capacities 15.9 to 30.7 m3 20.7 to 40.2 yd3

844Wheel Dozer

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844 Wheel DozerA strong power train combined with a heavy-duty front frame provides long life andeconomical operation.

Engineered for demanding work in largedozing applications, the Caterpillar 844Wheel Dozer is an ideal match for powergenerating utilities, clean up, roadmaintenance and production dozing at minesand in the general contracting industry.

Structures

The 844 features a box-section rear frameand four-plate front frame providingstrength and stability. Together theyprovide resistance to dozing shocks andstresses while absorbing shock loadsand twisting forces. pg. 7

Complete Customer Support

Your Cat® dealer offers a wide rangeof services that help you operate longerwith lower cost. pg. 15

Serviceability

Large engine doors, rear access stairsand convenient service platform withlarge doors enhance the serviceability ofthe 844. The Caterpillar dealer networkprovides World Class Customer Support.pg. 14

Cooling System

The Advanced Modular Cooling Systemwith Air-to-Air Aftercooling Systemhas been added to the 844 to help meetemissions requirements and improveefficiency, serviceability, visibility andsound levels. pg. 6

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Power Train

The Caterpillar® 3412E HEUI engineis Tier 2 compliant and combined withADEM II (Advanced Diesel EngineManagement II), axle-shaft brakes andimpeller clutch torque converter withlock-up clutch provides smooth consistentshifting with direct drive efficiency.pg. 4

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✔ New Feature

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Operator Station

Experience a high level of efficiencyand comfort with one-hand operationprovided by the STIC controller and astate-of-the-art cab. Operator productivityis increased with improved range ofviewing, reduced sound levels, improvedventilation and easy entry and exit.pg. 12

Blades and Blade Controls

Choose between semi-U, heavy-dutysemi-U and coal blades. Replaceablebolt-on cutting edges and bottom wearplates help extend blade life. A singlelever is used to hydraulically control allblade operations. pg. 10

Hydraulics

Two, independent hydraulic systemsand load-sensing steering are theinvisible force behind the mobilityand versatility of the 844. pg. 8

Caterpillar 3412E Hydraulic ElectronicUnit Injection Engine. Is rated at 463 kWnet (620 hp) at 2,000 rpm. The HEUI fuelsystem and Electronic Control Module(ECM) deliver power and efficiencyin the most demanding applications.Electronic control provides manybenefits:

• ADEM™ II (Advanced DieselEngine Management II)

• Automatic altitude deration

• Elevated low idle

• Cold weather starting mode

• Acceleration delay on startup toreduce engine wear

• Advanced diagnostic capabilities

• Automatic control of ether aid

• 500 hour oil change interval withCH-4 oil and new larger oil pan

• Dry-type air cleaner with primaryand secondary elements

• Engine/torque divider module isisolation mounted to the main frameto reduce machine vibration andstructure radiated noise

• Monotherm pistons

Starting System. Is direct-electric 24-voltwith a 100-amp alternator and two 12-volt190-amp-hour batteries.

Injection Timing. Is controlled withoutconcern for cam profile limitations.Complete control of engine speed providesadvantages in lower emissions, quieteroperation, reduced smoke, improved hotor cold starting, white smoke cleanupand high altitude operation.

Injection Duration. With the HEUI systemwill decrease proportionately withengine speed but can also electronicallycontrol the oil supply pressure. Thiscomplete control provides improvedengine performance and decreasedfuel consumption.

Injection Rate Shaping. Reduces nitrousoxide (NOx) emissions and reducesengine combustion noise.

1 Aftercooler. Lowers inlet chargetemperature. Reduces thermal stressesthat can cause premature wear of pistons,rings and liners.

2 High Injection Pressures. Independentof engine speed, decrease smoke andemissions while improving response.

3 Oil-Cooled Pistons and Full-Length,Water-Cooled Cylinder Liners. Providemaximum heat transfer for longercomponent life.

4 Engine Oil Cooler. Maintains optimumoil temperature for proper cooling andpressure lubrication. Engine coolingprovided is by the Multi-Row Modularradiator. Hydrostatic fan drive givesthe standard cooling package 110° Fambient capability.

Impeller Clutch Torque Converter(ICTC). Allows the operator to modulaterimpull from 100 percent to 20 percentof maximum rimpull. After 20 percentof maximum rimpull is achieved,further pedal travel applies the brake.The torque converter is equipped with alockup clutch for direct drive efficiency.

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844 power train components deliver dependable, reliable performance customers expectfrom Cat wheel dozers.

Power Train

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5 Impeller Clutch. Modulates the amountof engine power sent to the wheels.

6 Lockup Clutch. With Electronic ClutchPressure Control provides direct driveefficiency in second and third forwardgears and all three gears in reverse withhigher speeds and improved fueleconomy on long distance dozing.

ICTC Benefits.

• Improved calibration procedure

• Improved left pedal modulation

• Compensates for wear and providesthe ability to recalibrate for optimumleft pedal modulation regardless oftorque converter wear.

Planetary, Electronic, Power ShiftTransmission. Is the same transmissionfound in the 990 Series II wheel loader.Electronic shifting provides smoothconsistent shifts with finger tip controlshoused in the STIC controller. Thetransmission is built around a centershaft with a gear set cluster stacked end-to-end to distribute load, conserve space

and transfer energy efficiently. Largediameter perimeter clutches coupledwith high contact planetary gear setsprovide high torque carrying capacityfor long, trouble-free life.

Parking Brake. Is spring-applied, oil-released and dry disc. It is mountedon the transmission gear output shaft.The Caterpillar Monitoring System(EMS-III) alerts the operator if thetransmission is engaged while theparking brake is applied as well as ifpressure drops, in which case the brakewill automatically apply. Manualoverride is possible to allow movementof the machine.

• Self-diagnostics accessible throughCaterpillar Monitoring System

• Quick Shift

7 Final Drives. Are planetary consistingof a ring gear, three planet gears, aplanet gear carrier and a sun gear.

• Ring gears splined to reation hub

• Proprietary gear cutting and heattreat methods are used in themanufacturing of components

• Full-floating bronze sleeve bearingsare used on planet gears

• Oil-bath lubrication

8 Axle-Shaft, Oil-Disc Brakes. Are fullyhydraulic, completely sealed and neverneed adjustment. Disc face groovesprovide cooling even when brakes areapplied for a long, fade resistant life.

Design. Provides a larger cooling oilreservoir and thicker separator platesthan conventional brake designs. Thisgives the brake higher heat dissipationrates allowing higher capacity thanconventional oil-disc brakes. Duo-coneseals are located between the wheel andthe spindle.

9 Brake Location. Reduces service time.Conventional brakes require final drivedisassembly. The axle-shaft brakedesign allows brake service whileleaving the final drive intact. Reducedservice time and machine downtimekeep operating costs low.

Bevel Gear Sets and Differentials.Are common with the Cat 990 Series IIWheel Loader.

Service Brakes. Are four wheel,hydraulic, oil-dipped multiple discbrakes that are adjustment-free,completely enclosed and allowmodulated engagement withoutslack adjusters.

Secondary Brakes. Are fully modulatedand the front and rear service brakecircuits are isolated so one circuitcan operate if pressure drops in theother circuit.

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Advanced Modular Cooling System(AMOCS) with Air-to-Air AftercoolingSystem (ATAAC). In order to meetEPA Tier 2 and EU stage II emissionsrequirements for the Year 2002, thesoftware for the Cat 3412 HEUI enginehas been changed and the coolingsystem upgraded to an AMOCS thatutilizes the ATAAC system to achievelower particulate, NOx and soundoutput. The proven AMOCS systemis currently used on other Caterpillarmodels such as the 834G, 854G, 988Gand 992G and with ATAAC technologyeffective with the 834G and 988Gintroduction.

ATAAC System. Provides a separatecooling system for the intake manifoldair complementing the engine jacketwater cooling system. The ATAACsystem routes hot, compressed air fromthe turbo and cools it with a single pass,air-to-air aluminum heat exchanger. Thecooled compressed air is then deliveredto the engine intake manifold. Providingthe engine with cool compressed airgreatly reduces the emissions produced,meeting Tier 2 requirements for acleaner environment.

Separated Cooling System. Isolates theAMOCS radiator and demand fan fromthe engine compartment with a shieldallowing the radiator to receive outsideambient air through the side and topvents at a much lower temperature thanthe hot air from the engine compartment.This improves the system’s efficiencyand allows the radiator size to bedecreased and the rear hood to besloped, improving the rear viewing area.Also, sound levels are reduced due tothe lower fan speed of a more efficientcooling system.

AMOCS. Is a Caterpillar exclusivetechnology that improves serviceabilityand increases cooling efficiency by22 percent. Ambient working temperaturefor the standard 844 is 43° C (110° F).A high ambient cooling package with a50° C (122° F) capacity is available asan attachment.

Serviceability. Is a key benefit. Tubesare welded to a large, thick header,providing the strength of the tube-to-header joint that reduces the possibilityof coolant leaks. The AMOCS modularcore design allows removal of a singlecore without removing the entireradiator – reducing downtime throughease of serviceability. Replacing theindividual core also reduces repair costs.

Two Pass System. Offers increasedcooling capacity. Coolant travels fromthe engine to the fan side of the bottomtank, up the fan side of each core, overthe top, down the engine side of thecore, into the engine side of the bottomtank and back to the engine. The improvedflow pattern allows the coolant to passthrough the radiator twice for bettercooling. The AMOCS design improvesserviceability, reduces downtime andincreases cooling capability.

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Works with the engine to meet emissions standards as well as improve serviceability andreduce downtime.

Cooling System

ATAAC System(Air-to-Air Aftercooler)

Cooling System

AMOCSCores ATAAC

Cores IsolationShield

HydraulicallyDriven Fan

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Structure Welds. Are more than90 percent robotically welded.This provides highly consistent weldswith deep plate penetration and excellentplate fusion. The benefit is greaterfatigue strength and longer life thanwith conventional welding methods.

Castings. In the engine end-frame areused in critical high-stress areas to helpspread the load and reduce the numberof parts. The casting for the rear trunnionmount also serves as an engine mount,which provides a load path for the weightand torque of the engine to travel downto the trunnion and then on through tothe axle. Other castings used in theengine-end frame include: front trunnionmounts, steering cylinder brackets,articulation stops and lock link.

1 Box-Section Rear Frame. Absorbsshock loads and torsional forces, solidlymaintaining alignment for hitch pinsand driveline.

2 Four-Plate Front Frame. Providesmaximum structural strength to resisttwisting loads during dozing applications.

3 Upper and Lower Hitch Pins. Pivot ondouble-tapered roller bearings and areshaped to direct stress away from theend of the weld, resulting in a smoothertransition of stress loads.

4 Spread-Hitch Design. Helps square upthe frame and provides more clearancefor hydraulic lines. Double taperedroller bearings and hardened pins resistboth horizontal and vertical loads toincrease life. The spread hitch alsomakes service access easier.

Engine and Transmission Mounts.Are designed to use mushroom and cup-shaped ISO mounts, reducingcomponent vibration and sound levels.The engine mounts directly to the rearcross member, simplifying and improvingload transfer structure.

StructuresAdvanced design and materials provide superior strength.

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1 Two Separate, Hydraulic Systems.One for lift/tilt/tip and brakes, while theother is for steering and the hydraulically-driven engine cooling fan. Benefits oftwo systems are increased cooling andelimination of cross-contamination. If onesystem runs hot or is contaminated, theother will be unaffected.

2 Blade Control. Low-effort controlcomes from the single lever lift/tilt/tipcontrol that is floor-mounted and cableactuated with pressure compensationfor tilt/tip.

• Caterpillar built tandem vane pumpsprovide hydraulic flow for the lift,tilt and tip functions. The circuit iswell balanced to provide control whenall functions are used simultaneously.

• Well-proven pumps, valves andcylinders are common with thoseused on Caterpillar large track-typetractors.

• For improved serviceability, allhydraulic pumps are mounted ona single pump drive.

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Well-balanced hydraulics deliver precise low-effort control and trouble-free operation.

Hydraulics

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3 Load Sensing Steering with STICControl System. Is a revolutionarysystem that integrates steering andtransmission into a single controller.The variable displacement pumpmaximizes machine performance bydirecting power through the steeringsystem only when needed. More efficientuse of power results in decreased fuelconsumption and higher production.

• Simple side-to-side motions of thestick turn the machine right or leftoffering a 35 degree steering anglein both directions. Center-pointframe articulation allows the frontand rear wheels to track.

• Transmission shifting forward,neutral or reverse is controlled bythe operator’s fingers and gearselection is controlled by theoperator’s thumb.

XT-3 and XT-5 Hose. O-ring face sealsand large-bore lift and tilt cylinders topoff the hydraulic system, deliveringthe performance and durability ownersexpect. Reliable components reduceleaks and help protect the environment.

Hydrostatic Cooling Fan. Is used forengine, transmission and hydrauliccooling. A variable displacement pumpdrives the fan’s hydraulic motor so thatfan speed varies with coolant temperature.The fan draws only the power neededfor cooling, reducing fuel consumptionand increasing efficiency.

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Caterpillar Blades. Are designedwith excellent dozing and rollingcharacteristics.

• Capacities and widths are set toachieve increased productivity.

• Special design allows for spreadingof cover material as well as dozingof heavier loads.

• High-strength, pressed ribconstruction.

• Caterpillar large track-type tractorbolt-on cutting edges and bottomwear plates.

• Fitted with Caterpillar standardhardware and Ground EngagingTools (GET).

• Rebuildable for long blade life.

Coal Blade. Is designed for preciseand productive dozing while helpingto retain load control with increasedcapacity for lighter materials. Wingangles help retain the load while dozing.

Semi-U Blade. Combines thecharacteristics of the S and U bladesinto one package. Provides increasedcapacity with the addition of shortwings which include only the dozerend bits without sacrificing spreadingcharacteristics of straight blades.

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Caterpillar blades are built to handle tough applications and well-proven Cat componentsdeliver dependable service and ease of operation.

Blades and Blade Controls

Heavy-Duty Semi-U Blade. Has thesame configuration as the semi-U bladebut is built with thicker plates for moresevere applications.

Heavy-Duty Blade Linkage. Is commonwith a Caterpillar D9 Track-TypeTractor. These well-proven componentsare designed for tough applications.

• Lift cylinders raise and lower bladefor efficient dozing action.

• Two position tilt cylinder mountingfor increased flexibility for variousapplications.

• Cutting edges are DH-2 steel. Endbits are DH-3 to provide maximumservice life in tough materials

• Trunnions, pusharms and tag linkare sized for large dozing loads.

Single-Lever Blade Control. Hydraulicallyoperates blade raise, lower, tilt and tip.

Lift Circuit. Features four positions:raise, hold, lower and float with detentehold on float.

Tilt/Tip Circuit. Offers operator selectedsingle or dual-tilt and fingertip controlfor tip operation.

Low-Effort Control. Comes from thesingle-lever lift/tilt/tip control that isfloor mounted and cable actuated withpressure compensation for tilt/tip.

Single or Dual-Tilt Operation. Can beselected by the operator by using aswitch located on top of control lever.A generous range of tilt motion enablesexcellent control for dozing.

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Comfort and control — a top quality operator station helps maximize productivity.

Operator Station

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Cab Design. Is spacious and incorporatesinnovations for operator comfort andproductivity, includes an excellentviewing area, interior sound levelsbelow 75 dB(A), Caterpillar ComfortSeries seat, standard coat hook, cupholder, storage bin, sun visor andintermittent wet-arm wipers. It isalso radio-ready for two-way radios.

1 STIC Control System. Is a revolutionarysystem that integrates steering andtransmission into a single controller.Simple side-to-side motions of theoperator’s left arm turn the machineright or left. Transmission shiftingforward, neutral or reverse is controlledby the operator’s fingers, and gearselection is controlled by the operator’sthumb. These factors combine to producea fluid motion that reduces effort andallows the operator to work the machinefor long periods of time with little orno fatigue.

2 Left Pedal. Operates the ImpellerClutch Torque Converter for aboutthe first inch of travel, then engagesthe brakes. Within the first inch ofpedal travel, rimpull can be controlledfrom 100 percent to 20 percent.

3 Comfort Series Seat. With airsuspension and retractable seat beltis designed for comfort and support.Seat cushions reduce pressure on thelower back and thighs while allowingunrestricted arm and leg movement.The seat has three height levels.The retractable seat belt remains offthe floor and is easy for the operatorto reach.

4 Quick-Shift Feature. Allows quickercycle times by shifting from first forwardto second reverse.

5 Throttle Lock. Allows the operator topreset the engine speed and concentrateon productivity. The throttle lock can bedeactivated by pressing the brake pedal.

6 Caterpillar Monitoring System (EMS-III). Continually monitors variousmachine systems through three instrumentclusters and provides a three-levelwarning system to alert the operatorof immediate or pending problems.It shares information with the engine,hydraulic and transmission controls thatcan be used during servicing to simplifyservice and troubleshooting.

• GaugesDisplay engine coolant, transmissionoil and hydraulic oil temperatures,engine oil pressure and fuel tank level.

• Tachometer/SpeedometerDisplay engine speed and gearindicator.

• Alert IndicatorsInclude charging system, parking/secondary brake, supplementalsteering, brake oil pressure, enginecoolant flow and transmissionfilter status.

7 Floor-Mounted Hydraulic BladeControls. Are adjustable fore and aft,with a height-adjustable armrest sooperators of any size can find acomfortable operating position. A singlelever control allows operator to controlblade functions: lift/lower, tip and tilt.The switch control on top of controllever allows option of single or dual-tiltoperation.

8 Torque Converter Lock-up Clutch.Is activated when the operator pressesa switch on the console. The 844automatically shifts from torqueconverter drive to direct drive when aset speed in second and third forward orall gears in reverse is reached, providingfaster travel speeds and less fuelconsumption.

Large Viewing Area. Enhances viewingin all directions. Bonded glass in thefront window eliminates distractingmetal frames with the best operatorvisibility to the blade.

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Easy Maintenance. In addition to theservicing features built into the engine,the 844 includes:

• Rear Access Stairs. For easy,comfortable access for operatorsand service personnel.

• Large Engine Access Doors. Provideexcellent access to service points, engineoil dipstick, diagnostic connector, engineoil and fuel filters, starting receptacle,air filter indicator, air filters, fuel/waterseparator and the ether starting aidcartridge.

• Large Service Platform. Providespassage to hydraulic filter, fuel fill andtransmission filters through easy-to-open doors.

• Large Door. Provides entrance totransmission and pumps when serviceis required.

• Large Platform Door. Provides accessto fuses and electronic control modules.

• Batteries. Are accessible through hingeddoors in bumper.

• Side Access Doors. On the radiatorguard provide easy access for radiatorcleanout.

• Grouped and Labeled Lube Points.Accessible at ground level, make dailylube maintenance quick and easy.

• Sight Gauges. For the hydraulic tanksand radiator provide quick checks forfluid levels.

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Less time spent on maintenance means more time on the job.

Serviceability

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Machine Selection. Make detailedcomparisons of the machines underconsideration before purchase.Cat dealers can estimate componentlife, preventative maintenance costand the true cost of lost production.

Purchase. Look past initial price. Considerthe financing options available as wellas the day-to-day operating costs. Lookat dealer services that can be includedin the cost of the machine to yield lowerequipment owning and operating costsover the long run.

Customer Support Agreements.Cat dealers offer a variety of productsupport agreements and work withcustomers to develop a plan that bestmeets specific needs. These plans cancover the entire machine, includingattachments, to help protect thecustomer’s investment.

Product Support. You will find nearlyall parts at our dealer parts counter.Cat dealers use a worldwide computernetwork to find in-stock parts tominimize machine downtime. Savemoney with genuine Cat Reman parts.You receive the same warranty andreliability as new products at costsavings of 40 to 70 percent.

Operation. Improving operatingtechniques can boost your profits.Your Cat Dealer has training videotapes,literature and other ideas to help youincrease productivity.

Maintenance Services. Choose fromyour dealer’s range of maintenanceservices when you purchase yourmachine. Repair option programsguarantee the cost of repairs up front.Diagnostic programs such as S•O•SSM andCoolant Sampling and Technical Analysishelp you avoid unscheduled repairs.

Replacement. Repair, rebuild or replace?Your Cat dealer can help you evaluatethe cost involved so you can make theright choice.

Cat Dealer services help keep machines operating longer with lower costs.

Complete Customer Support

16 844 Wheel Dozer specifications

Weights

Operating Weight 70 815 kg 156,120 lb

Transmission

Converter Drive - Forward 1 7 kph 4.4 mphConverter Drive - Forward 2 12.2 kph 7.6 mphConverter Drive - Forward 3 21 kph 13 mphConverter Drive - Reverse 1 7.7 kph 4.8 mphConverter Drive - Reverse 2 13.4 kph 8.4 mphConverter Drive - Reverse 3 23 kph 14.3 mphDirect Drive - Forward 1 7.2 kph 4.5 mphDirect Drive - Forward 2 12.8 kph 7.9 mphDirect Drive - Forward 3 22.5 kph 14 mphDirect Drive - Reverse 1 7.9 kph 4.9 mphDirect Drive - Reverse 2 14.1 kph 8.8 mphDirect Drive - Reverse 3 24.8 kph 15.4 mph

• With 45/65 R39 XLD D1A - Type A (L4) tires.

• Converter drive 2 percent rolling resistance.

Engine

Engine Model Cat® 3412E dieselGross Power 503 kW 675 hpFlywheel Power 463 kW 620 hpFlywheel Power - Caterpillar 463 kW 620 hpFlywheel Power - EEC 80/1269 463 kW 620 hpFlywheel Power - ISO 9249 463 kW 620 hpFlywheel Power - SAE J1349 458 kW 613 hp(JAN90)Flywheel Power - DIN 70020 648 PSBore 137 mm 5.4 inStroke 152 mm 6 inDisplacement 27 mm 1,649 in3

• These engine ratings apply at 2,000 rpm when tested underthe specific standard conditions for the specified standard.

• Power rating conditions are based on standard air conditionsof 25° C (77° F) and 99 kPa (29.32 in Hg) dry barometerusing 35° API gravity fuel having an LHV of 42 780 kJ/kg(18,390 Btu/lb) when used at 30° C (86° F) [ref. a fuel densityof 838.9 g/L (7.001 lb/gal)].

• Net power advertised is the power available at the flywheelwhen the engine is equipped with fan, air cleaner, mufflerand alternator.

• No derating required up to 2286 m (7,500 ft) altitude.

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Machine Ground Speed (kph)

2 6 8 12 16 18 22

354045

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Torque Converter

Direct Drive

17844 Wheel Dozer specifications

• ROPS meets SAE J1040 APR 88 SAE J394 and ISO 3471: 1994.

• FOPS meets SAE J231 JAN 81 and ISO 3449: 1992 Level IIcriteria.

• The operator sound exposure Leq (equivalent sound pressurelevel) measured according to the work cycle proceduresspecified in ANSI/ASAE J1166 OCT 98 is 72 dB(A), for the caboffered by Caterpillar, when properly installed and maintainedand tested with the doors and windows closed.

• Hearing protection may be needed when operating with anopen operator station and cab (when not properly maintainedor doors/windows open) for extended periods or in noisyenvironment.

• The exterior sound pressure level for the standard machinemeasured at a distance of 15 m (49.2 ft) according to the testprocedures specified in SAE J88 JUN 86, mid-gear-movingoperation, is 82 dB(A).

• The sound power level is 116 dB(A) measured accordingto the dynamic test procedure and conditions specifiedin ISO 6395:1988/Amd. 1:1996 for a standard machineconfiguration.

• For “CE” marked configurations, the labeled sound powerlevel is 114 dB(A) measured according to the testprocedures and conditions specified in 2000/14/EC.

Brakes

Brakes Meets SAE/ISO 3450 1996.

Axles

Front FixedRear Oscillating ±11°Maximum Single-Wheel 572 mm 22.5 inRise and Fall

Tires

Tire Choices Two choices available.

• 45/65 R39 L-4 (XLDDIA), Michelin

• 40.5/75 R39 1-Star, Goodyear

• Caterpillar recommends that you consult a tire supplierto evaluate all conditions before selecting a tire model.Other special tires are available on request.

• Tubeless, low-aspect ratio. All steel radial construction forincreased traction and stability, lower rolling resistance.

Operating Specifications

Blade Capacities 15.9 to 30.7 m3 20.7 to 40.2 yd3

Hydraulic System

Output at 2,126 rpm and 342 L/min 89 gal/min6894 kPa (1,000 psi)Cylinder, double-acting: 133.5 mm x 5.25 in xLift, Bore and Stroke 1535 mm 60.5 inCylinder, double-acting: 209.5 mm x 8.25 in xTilt and Tip, Bore and Stroke 188 mm 7.5 inRelief Valve Setting - 18 650 kPa 2,700 psiBulldozer (Large Pump)Relief Valve Setting - 20 150 kPa 2,920 psiTilt Cylinders (Small Pump)

• Blade control system with double-section vane pump withSAE No. 10 oil at 66° C (150° F).

Steering

Minimum Turning Radius 9.9 m 32.5 ft(Over Tires)Hydraulic output at 2,128 rpm 410 L/min 108 gal/minand 6900 kPa (1,000 psi)Relief Valve Setting 31 005 kPa 4,500 psi

• Full hydraulic load sensing steering system meets SAE J1511FEB94 and ISO 5010: 1992 specified standards.

Service Refill Capacities

Fuel Tank - Standard 984 L 260 galCooling System 190 L 50.2 galCrankcase 95 L 25 galTransmission 110 L 29 galHydraulic Tank 541 L 141 galDifferentials and Final Drives 271 L 71.6 gal- FrontDifferentials and Final Drives 261 L 68.9 gal- RearHydraulic System - Blade 174 L 45 galand Brakes (Tank Only)Hydraulic System - Steering and 132 L 34.9 galEngine Cooling Fan (Tank Only)

Cab

ROPS/FOPS Meets SAE and ISOstandards.

Sound Performance Levels Meets ANSI, SAE and ISOstandards.

• Caterpillar cab with integrated Rollover Protective Structure/Falling Object Protection System (ROPS/FOPS) are standard.

• Standard air conditioning system contains theenvironmentally friendly R134a refrigerant.

18 844 Wheel Dozer specifications

Blade Overall Digging Ground Maximum Total OperatingType Capacity Width Height Depth Clearance Tilt Weight WeightSemi-U 15.9 m3 5418 mm 2024 mm 465 mm 1459 mm 829 mm 7273 kg 70 815 kg

20.7 yd3 213.3" 79.7" 18.3" 57.4" 32.6" 16,034 lbs 156,120 lbs

Heavy-dutySemi-U 15.9 m3 5419 mm 2223 mm 477 mm 1372 mm 940 mm 7763 kg 71 298 kg

20.7 yd3 213.3" 87.5" 18.8" 54" 37" 17,100 lbs 157,186 lbs

Coal 30.7 m3 5846 mm 2024 mm 465 mm 1372 mm 940 mm 6273 kg 69 815 kg40.2 yd3 230.2" 79.7" 18.3" 54" 37" 13,830 lbs 153,916 lbs

Semi-U Blade: This unit combines the characteristics of the S and U blades into one package. It has increased capacity by the addition ofshort wings which include only the dozer end bits.

Blade Specifications

ROPS5067 mm(16' 7") 4723 mm

(15' 6")

4600 mm(15' 1")

10 940 mm(35' 11")

2300 mm(7' 7")

3615 mm(11' 10")

475 mm(19")

3512 mm(11' 6")

All dimensions are approximate.

Dimensions

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Standard EquipmentStandard and optional equipment may vary. Consult your Caterpillar Dealer for specifics.

Storage for lunch box, cupSunshade/visor, front and rearThrottle lockTinted glassTransmission gear indicatorWet-arm wiper/washers, front and rear

Power TrainCat 3412E HEUI engineFuel priming aidBrakes: Parking: Dry, multi-disc brake; transmission mounted,

Service/Secondary; and enclosed, wet, multi-disc brakeat each wheel

Impeller Clutch Torque Converter with lockup clutchPrecleaner/ejectorRemote-mounted hydraulic engine fanSeparated cooling systemSound suppressed mufflerSupplemental steeringSwing-out cooler coresTransmission,

533 mm (21 in) planetary power shift (electronic)3-speed forward/3-speed reverse

Other standard equipmentBackup alarmCold weather starting systemDrawbar hitch with pinFenders (front)High speed oil change systemHydraulic oil coolerMufflerLighting, general purpose (four)Locking engine enclosuresPower train/guardRear access stairsVandalism protection and caplocksVenturi stacks

Tires45/65 R39 L-4 (XLDDIA), Michelin

ElectricalAlternator, 100-ampere Converter, for 12-volt accessoriesDeutsch connectorsDiagnostic connector for starting and charging systemsElectric starter (heavy-duty)Electrical system, 24-voltExternal lighting system, front and rearMaintenance-free batteriesStarting receptacle for emergency starting

Operator EnvironmentAir conditioner, R134a refrigerantComfort Series Seat with air suspensionCigar lighter and ashtray Coat hookCaterpillar Monitoring System (EMS-III)

Action alert system, three-categoryGauges:

tachometerfuel levelhydraulic oil temperaturetransmission oil temperature engine oil pressure coolant

temperatureDome light (cab)Electric hornExternal two-post ROPS structureHeater and defrosterLoad-sensing steering Quick-shift featureRadio-ready cab for entertainment or two-way radio

(three-point mounting)Rearview mirrors (interior and exterior mounted)Retractable seat belt 76 mm (3 in) wideROPS cab with sound suppressionFloor mounted hydraulic controlsSight gauges, hydraulic oil and engine coolantSingle-lever blade controlSTIC Control System

844 Wheel Dozer specifications

kg lb

Blades

Semi-U 7273 16,034

Heavy-duty Semi-U 7763 17,100

Coal 6273 13,830

Fuel system 1 3

High Ambient Cooling Arrangement 12 26.5

kg lb

Starting aids

Diesel fuel heater 7 15

Heater, engine coolant 4 8

Tires – 40.5/75 R39 1-Star, Goodyear –1030 –2,272

Optional EquipmentWith approximate changes in operating weights.

R

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© 2002 CaterpillarPrinted in U.S.A.

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

See your Caterpillar dealer for available options.

AEHQ5307-01 (1-02)

Replaces AEHQ5307

844 Wheel Dozer