®®

EngineEngine Model Caterpillar® 3456 EUIGross Power 388 kW 520 hpFlywheel Power 354 kW 475 hp

Operating SpecificationsOperating Weight 50 183 kg 110,634 lbRated Payload 11.4 tonnes 12.5 tons

BucketsBucket Capacities 6.3 to 7.0 m3 8.2 to 9.2 yd3

988GWheel Loader

2

988G Wheel LoaderImproved performance and rugged durability combine with operator comfort for maximumproductivity.

Revolutionary design, Caterpillar quality.Electro-hydraulic controls, increased powerand torque rise, front linkage and unmatchedoperator comfort work together for increasedperformance and added durability to makethe 988G an innovative, 21st century largewheel loader geared for maximumproduction in the toughest condition.

Customer Support

Your Cat® dealer offers a wide range ofservices that help you operate longerwith lower costs. pg. 15

Application Truck Match

Increased performance and good passmatching make the 988G a versatileperformer. pg. 14

Hydraulics and Electronic Monitoring

Innovative electro-hydraulics play a keyrole in performance of the 988G andprovide low operator effort. Increasedhydraulic efficiency improves lift andtilt cycle time for reduced overall cycletime. The tradition of reliable, high-performance Caterpillar hydraulicscontinues. pg. 8

Power Train

The Cat 3456 EUI diesel engineis Tier 2 compliant. A new cylinderblock is stronger and lighter weight.The Caterpillar planetary power shifttransmission and impeller clutch torqueconverter provide smooth, consistentshifting with finger tip control. Electroniccontrols contribute to increased levelsof productivity. pg. 6

✔

Structures and Fabricated Box Boom

The articulated frame design features ahigh-torsion, compact, load-absorbing,front frame and a large, box-section,engine-end frame. Fabricated boomand linkage geometry increase dumpclearance, provide improved breakoutand lift forces and increase the viewingarea to the bucket corners. pg. 4

3

Maintenance and Serviceability

Most daily maintenance checks areperformed from the machine’s left side,facilitating quick start up. Case drainfilters for main hydraulic, steering andfan pumps protect against contamination,and improved access to majorcomponents enhance serviceabilityand increase uptime. pg. 16

Bucket Match

Improve machine performance andincrease stability by selecting the rightbucket for your application and materialdensity. pg. 13

Buckets and Ground Engaging Tools

Choose between 6.3 m3 (8.2 yd3) and7.0 m3 (9.2 yd3) capacity buckets, spadeedge and straight edge buckets andvarious Ground Engaging Tools tomatch job conditions. These Caterpillarbuckets retain the proven shell-tineconstruction design for unmatcheddurability. pg. 12

Operator Station

Experience a new level of efficiency,comfort and productivity with one-handSTIC operation, a 38 percent larger cab,low-effort, fingertip lift and tilt controls,improved visibility, reduced soundlevels, improved ventilation and easierentry and exit. pg. 10

✔ New Feature

Structures. Combine the use of roboticwelding and castings in critical high-stress areas. More than 90 percent of the988G structure is robotically welded toprovide highly consistent welds andincreased strength. Castings are alsoused in several areas to increase strengthby helping to spread the loads andreduce the number of parts.

1 Full Box-Section Frame. Has beenimproved for maximum strength andminimum weight. The frame rail is nowextended further forward, improvingrail to hitch strength.

2 Box-Shaped Tower. Is designed forimproved resistance to twisting formaximum strength. The tilt cylindertower’s high-strength steel plates directstress down to the lift cylinder castmounting tube, absorbing impact andloading forces. This design results ina narrower tower which gives betteroperator visibility.

4

Structures and Fabricated Box BoomSuperior design of structures, along with bold, new box-section front linkage provide superior strength.

6

2

51

4

3

3

3 Upper and Lower Hitch-Pins. Pivot ondouble-tapered roller bearings. The hitchplates are shaped to direct stress awayfrom the end of the weld, resulting in asmoother transition of stress loads intothe frame.

4 Spread-Hitch Design. Increases thespread 26 percent to help square-up theframe and provide increased clearancefor access to the hitch and hydraulic lines.

5 Steering Cylinder Mounts. Are locatedon the axle pads providing efficienttransfer of steering loads to the axle.

6 Fabricated Box Boom. Replaces thetraditional steel plate lift arms foundon wheel loaders. This design featuresforked ends for easier service, fasterassembly and increased reliability.Castings in high stress areas smooththe transition of stress distribution forexcellent service life. The new boomand dual bucket links work together forincreased breakout force, better torsionalresistance and higher lift capacity.

• Fabricated Boom Box-Section Design.Has more torsional stiffness than a Z-bardesign. (With the parallel lift arm design,corner loading the bucket sends stressesup the lift arm, through the cross tubewelding and up the other lift arm.)The box-section design spreads stressesover the full length and perimeter of theboom, allowing stress transfer throughparent material. This resists twistingand prevents stress paths that can leadto cracking.

Weld Joint

Load Path

Load Path(Full Length)

5

1 Cat 3456 EUI Diesel Engine. Is basedon one of the most successful enginesoffered by Caterpillar, the 3406E.The 3456 is Tier 2 compliant andfeatures increased horsepower andefficient fuel management for quickresponse, high productivity andexceptional service life. A new,sculptured cylinder block providesgreater strength and lighter weight.

• 42 Percent Torque Rise. Provideshigh lugging force during digging andacceleration in high rimpull conditions.The torque curve effectively matchesthe transmission shift points to providemaximum efficiency and fastercycle times.

• Electronic Unit Injection (EUI). Is aproven high-pressure, direct injectionfuel system that electronically monitorsoperator demands and sensor inputs tooptimize engine performance.

• Air Cleaners. Are dry-type radial sealwith primary and secondary elementsand precleaner.

• ADEM™ III (Advanced Diesel EngineManagement) System. Controls thefuel injector solenoids to monitor fuelinjection. This system provides automaticaltitude compensation, air filter restrictionindication and will not allow the engineto fire until it has oil pressure, actingas a cold start protection and a formof pre-lube.

• Air-to-Air Aftercooler (ATAAC).Provides a separate cooling system forthe intake manifold air. The ATAACsystem routes hot compressed air fromthe turbo and cools it with a single pass,air-to-air aluminum heat exchanger.The cooled compressed air greatlyreduces the emissions produced,meeting Tier 2 requirements.

2 Separate Engine Cooling System.Isolates the radiator and fan from theengine compartment for more efficientcooling and allows for a sloped hoodfor increased viewing.

• Advanced Modular Cooling System(AMOCS). Improves cooling capabilitiesby using a parallel flow system withseven cores. Serviceability is improvedwith AMOCS as there is no top tankto remove.

6

Power TrainCat power train delivers top performance and durability in tough applications. Changes to the aftercooler, injectors, bearings and pistons help improve startability, response, power,emissions and fuel consumption.

6

2

5

14 3

2

3 Electronically Controlled CaterpillarPlanetary, Power Shift Transmission.Features perimeter-mounted, largediameter clutch packs that controlinertia for smooth shifting andincreased component life.

4 Impeller Clutch Torque Converter(ICTC). Combined with the RimpullControl System (RCS) allows theoperator maximum flexibility inmodulating rimpull.

• Improved calibration procedure

• Improved left pedal modulation

• Compensates for wear by providingthe ability to recalibrate for optimumleft pedal modulation regardless oftorque converter wear

• The impeller clutch torque convertoruses the left brake pedal to modulaterimpull from 100 to 20 percent forreduced tire slippage. After 20 percentis achieved, further pedal travelapplies the brake.

• RCS allows the operator to selectfrom four preset maximum rimpullsettings, other than 100 percent, thatare available in first gear (90, 85, 75and 65 percent).

• A lock-up clutch torque converterfor direct drive efficiency is alsoavailable as an optional attachment.

• Final Drives. Feature planetaryreduction at each wheel. Torque isdeveloped at the wheel, which gives lessstress at the axle shafts. The planetaryunits can be removed independentlyfrom the wheels and brakes.

5 Heavy-Duty Axles. Feature optional axleoil coolers, permanently lubed universaljoints and stronger axle components inboth the differentials and final drivesfor increased performance, serviceabilityand durability. Conventional differentialis standard.

• Free-Floating Axle Shafts. Can beremoved independent of the wheelsand planetaries for quick and easyserviceability.

• Optional Axle Oil Cooling System.Features two circuits that circulateoil from the differentials through an oil-to-air cooler and filter and backto the brakes. This system providesincreased oil life and improvescomponent performance and durability.The system automatically turns on andoff at a preset oil temperature.

6 Axle-Shaft, Oil Disk Brakes. Areadjustment-free, fully hydraulic andcompletely sealed. Disc face groovesprovide cooling even when brakesare applied, for a long, fade-resistantservice life.

• Location of the brakes improvesserviceability. The axle-shaft brakedesign allows brake service whileleaving the final drive intact.

• Axle-shaft brakes require less forceby operating on the low torque sideof the axle. Combined with improvedaxle oil circulation for increasedcooling, the oil-enclosed, multiple-disc brake design improves durability.

• Parking brake is spring-applied, oil-released and dry disc. It ismounted on the transfer gear outputshaft. Manual override is possibleto allow movement of the machine.

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

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

Brak

es(2

0%Ri

mpu

ll)

100% RimpullSelected

Left Pedal

20% RimpullSelected

7

4

1 Electro-Hydraulic Control System.Increases hydraulic efficiency andenhances operator comfort through low-effort fingertip controls. XT-3 and XT-5hose along with reliable componentsreduce the risk of leaks and blown lines,helping protect the environment.

2 Lift and Tilt System. Consists oflarger bore lift and tilt cylinders anda two position main hydraulic pumpcontributing to increased performanceand serviceability.

• Two Position Main Hydraulic Pump.Is controlled by the Electronic ControlModule (ECM). A solenoid valve controlsthe pump displacement, allowing theECM to adjust hydraulic flow duringthe loader cycle. This strategy results infaster hydraulics and greater lift forcesleading to optimized performance.

3 Load Sensing Steering. With the STICcontrol system integrates steering andtransmission into a single controller.STIC operated pilot valve controls theflow to steering cylinders. The steeringsystem utilizes a variable displacementpump for maximum machine performanceby directing power through the steeringsystem only when needed.

4 Case Drain Filtration. A total ofthree filters for the main hydraulic,steering and fan pumps protect againstcontamination with easy accessfor service.

5 Demand Fan. A speed controlled,hydraulic fan that provides maximumcooling efficiency by directing theappropriate amount of power throughthe fan system based on coolanttemperature.

Advanced Electronics. Play a majorrole in the operation of the 988G.Productivity improvements, enhancedserviceability, increased operatorefficiency and lower costs are directbenefits of the 988G advanced electronics.

8

Hydraulics and Electronic ControlsEfficient, well-balanced hydraulics and low-effort electronic controls mean high performance and exceptional durability.

2

22

5

1

4

3

3

9

6 Caterpillar Monitoring System (EMS-III).Continually monitors various machinesystems 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 controlsthat can be used during servicing tosimplify service and troubleshooting.The Caterpillar Monitoring System alsoallows for new software to be uploadeddirectly to the cab.

• Optional Payload Control System.Tracks data regarding the load in thebucket. It also features a numeric keypadand easy-to-view display. An availableprinter makes onboard ticket printingpossible.

• Optional Ride Control. Provides aboom suspension system by placingan accumulator in the boom circuit,reducing fore and aft pitch over roughterrain. This results in a smoother,more comfortable ride, allowing higherload and carry speeds, increased loadretention and component life.

• Loose Material Mode. Providesmaximum hydraulic speed andefficiency for loading in easilypenetrated loose material.

6

10

Operator StationA new industry standard for comfort and efficiency.

15

15

15

16

World Class Cab. With over 3.18 m3

(112 ft3) of volume incorporatesinnovations for operator comfort,maneuverability and productivity.

Features include outstanding viewingarea, improved cab ventilation, interiorsound levels below 77 dB(A), standardcoat hook, cup holder, storage bin,

intermittent wet-arm wipers, room fora large lunch cooler and radio-ready.

3

2

1

5

4

6

7

1 STIC Control System. Combines gearselection and steering into one controllever that requires less effort and providessmooth shifting. Side-to-side motionsfor steering, finger operated directioncontrol and thumb operated buttons forgear selection combine to provide a fluidmotion that reduces effort and allows theoperator to work the machine for longperiods of time with little or no fatigue.

2 Left Pedal. Operates the impeller clutchtorque converter/braking while the rightpedal operates standard braking.

3 Cat Comfort Seat. Replaces the previousContour Series Seat with more foam inkey parts of the seat back, thicker seatcushions, automotive-style lumbarsupport and an all-new, ergonomicdesign translate into greater operatorcomfort, less fatigue and consistentproductivity throughout the shift.The seat is a six-way adjustable airsuspension seat with a retractable seatbelt, headrest and adjustable armrestsfor optimal comfort and high productivity.

4 Electro-Hydraulic Controls andArmrests. Provide low effort, fingertipcontrol for enhanced comfort and stability.

• Floor-mounted controls and armrestsare fore, aft and height adjustable toaccommodate operators of any sizein a comfortable operating position.

5 Caterpillar Monitoring System (EMS-III).Display system provides informationon the machine’s major componentsand system.

• Gauge displays fuel tank level andtemperatures for engine coolant, powertrain and hydraulic oil. Tachometeris an analog gauge with digital readoutfor gear selection and ground speed.

• Alerts operator if transmission isengaged while parking brake isapplied. If pressure drops, theparking brake applies automatically.

• Main module consists of ten faultindicators and one display panel.

6 Throttle Lock. Allows operator to pre-set the engine speed for a varietyof applications, resulting in faster cycletimes and increased productivity.

7 Rimpull Control System (RCS) Switch.Turns RCS on and off.

8 Rimpull Control System (RCS). Has fourfactory preset reduced rimpull settings(90, 85, 75 and 65 percent of rimpull).Reduced rimpull settings can be modifiedby the dealer to operator preference orto better match ground conditions.

9 Kickout Positioner Control. Allows theoperator to set customized upper, lowerand bucket dig angle kickouts formaximum operating efficiency.

10 Optional Ride Control Switch. TurnsRide Control to off or automatic position.

11 Autoshift. Allows the operator toset the maximum gear into which thetransmission will be allowed to shift.This feature contributes to additionalcomfort and focus on the job. The switchalso offers a manual position for operatorcontrolled shifting.

12 Optional Lock-Up Clutch TorqueConverter Switch. Activates the lock-upclutch for direct drive efficiency.

13 Loose Material Operating Mode.Tailors hydraulics to provide maximumloose material loading efficiency.

14 Front and Rear Window Wiper/Washers. Are within easy reach tomaintain a clear field of vision.

15 Improved Viewing Area. With bondedfront windshield eliminates distractingmetal frames for excellent bucketand work site visibility. An internalROPS improves peripheral viewing byeliminating the large structure outsidethe cab.

16 Electro-Hydraulic Lock-Out Switch.Disables hydraulic controls.

11

Upper Left Console

Upper Right Console

8913

11121014

14

Buckets. Ranging from 6.3 m3 (8.2 yd3)to 7.0 m3 (9.2 yd3) may be configuredfor a variety of impact and abrasiveconditions. All buckets are built withshell-tine construction (1) that resiststwisting and distortion and featurereplaceable, weld-on wear platesto protect the bottom of the bucket.The integral rock guard (2) helps retainbig loads while heavy-duty pins andretainers (3) provide durability.

Spade-Edge Rock Buckets. With bolt-on segments are available in 6.4 m3

(8.33 yd3), 6.6 m3 (8.7 yd3) and 6.9 m3

(9.0 yd3). Each accepts up to two sets ofsidebar protectors (4), feature shouldered,double-strap adapters, easily changedbolt-on segments and several tip options.

Straight-Edge Buckets. Are availablein 6.3 m3 (8.2 yd3) Straight-Edge Rockand 7.0 m3 (9.2 yd3) General Purposeconfigurations. The Straight-EdgeRock bucket features shouldered,double strap adapters and acceptstwo sets of sidebar protectors, bolt-onsegments and tips. The General Purposebucket is available with bolt-on cuttingedge, bolt-on adapters or bolt-onadapters with segments.

High Abrasion Bucket. Is availablewith 6.4 m3 (8.33 yd3) capacity and isrecommended for use in face loadingwhere high abrasion and moderateimpact is encountered. This bucketfeatures additional wear protectionitems including: independently attachededge and adapter covers, additionalliners and wear plates, one set of sidebarprotectors and a thicker base edge.

Heavy-Duty Quarry Bucket. Is availableas a 6.4 m3 (8.33 yd3) capacity bucketand is recommended for use in faceloading where moderate abrasion andhigh impact is encountered. It featuresadditional wear protection items,including: four sidebar protectors (4),thicker base edge and adapters (5),additional liners and wear plates (6)and bolt-on half arrow segments (7).

Bucket Controls. Feature electro-hydraulic lift and tilt circuits for lowerlever effort.

Lift Circuit. Has four positions: raise,hold, lower and float and can adjustautomatic upper and lower kickoutsfrom the cab.

Tilt Circuit. Features three positions:tilt back, hold and dump. It can adjustautomatic bucket positioner to desiredloading angle from the cab and doesnot require visual spotting.

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Buckets and Ground Engaging ToolsCaterpillar buckets and Ground Engaging Tools provide the flexibility to match the machineto your application.

1

2

5

6

73

4 4

Spade-Edge Rock General Purpose Heavy-Duty Quarry

Buckets and GET. The 988G offers avariety of bucket types and availableGround Engaging Tool configurationsto properly configure the machine basedon material density, impact and abrasion.

Depending on your material densities, the988G has available a 6.4 m3 (8.33 yd3)Spade Nose bucket with teeth and bolt-onsegments for improved performanceand edge protection.

Increased full turn static tip load,horsepower and hydraulic capabilitiesallow the 988G to effectively utilizethe 6.6 m3 (8.7 yd3) and 6.9 m3 (9.0 yd3)bucket size in lighter materials suchas limestone.

To better match your 988G to materialconditions, contact Caterpillar forspecialty bucket needs.

13

Bucket MatchProper bucket and application match delivers increased stability and peak performance.

110% 90%

110%

100%

110% 90%100%

100% 90%

2200

1300 1500 1700 1900

Material Density

NOTE: Percentages shown represent bucket fill factor

Standard

Bu

ck

et

Siz

e

2400 2600 2800 3000 3200 3400 lb/LCY

yd3

kg/LCM

m3

9.06.9

6.6

6.4

8.7

8.33

2000

- Center point at 100% fill

Changes in bucket weight, including field installed wear iron, can impact rated payload. Consult your Caterpillar dealer forassistance in selecting and configuring the proper bucket for the application. The Caterpillar Large Wheel Loader PayloadPolicy is a guideline intended to maximize wheel loader structural and component life.

Bucket Selection Guide and Matrix

Performance. The 988G is an aggressivefirst gear loader for face and bankexcavation. With increased dumpclearance, the 988G can easily load 37-63 tonnes (40 to 70 ton) off-highwaytrucks. Increased performance and goodpass match make the 988G a versatileperformer with a cost per ton that willhelp your bottom line.

The versatility of a material handler isdesigned into the machine. With balancedrimpull and hydraulics, the 988G is anaggressive loader that gets the job donequickly and efficiently in loose orstock-pile material and in load andcarry work.

14

Application Truck MatchMatched payloads and matched buckets ensure optimum performance.

988G

Du

mp

Cle

ara

nce &

Reach

3.9

9 m

(13' 1")

& 2

.10 m

(6' 11")

Truck Payload

4 pass

5 pass

3 pass

Metric Tons35 40 45 50 55 60

35 Short Tons65 7040 45 50 55 60

Large Wheel Loader/Truck Application Match

769D = 36 Metric Tons (40 Short Ton) nominal payload771D = 41 Metric Tons (45 Short Ton) nominal payload773E = 54 Metric Tons (60 Short Ton) nominal payload775E = 63 Metric Tons (70 Short Ton) nominal payload

988G Rated Payload: Standard Arrangement = 11.4 metric ton (12.5 short ton)

15

Machine Selection. Make detailedcomparisons of the machines underconsideration before purchase. CatDealers can estimate component life,preventative maintenance cost andthe true cost of lost production.

Purchase. Look past initial price.Consider the financing options availableas well as the day-to-day operatingcosts. Look at dealer services that canbe included in the cost of the machineto yield lower equipment owning andoperating costs over 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, includingwork tools, to help protect thecustomer’s investment.

Product Support. You will find nearlyall parts at our dealer parts counter.Cat Dealers use a world-wide computernetwork to find in-stock parts to minimizemachine down time. Save money withgenuine Cat Remanufactured 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. More and moreequipment buyers are planning foreffective maintenance before buyingequipment. Choose from your dealer’swide range of maintenance services atthe time you purchase your machine.Repair option programs guarantee thecost of repairs up front. Diagnosticprograms such as S•O•SSM and CoolantSampling and Technical Analysis helpyou avoid unscheduled repairs.

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

Customer SupportCat Dealer services help you operate longer with lower costs.

Maintenance and Repair. Is easierthrough monitoring key functions andlogging critical indicators. Electronicdiagnostic access is possible with asingle tool, the Electronic Technician(ET). In addition to the servicing featuresbuilt into the engine, the 988G includes:

• Daily Maintenance Checks. Most canbe performed from the left side of themachine, making it part of an easy pre-start routine. Routine maintenancepromotes long service life and durability.

• Advanced Modular Cooling System.Allows service technicians to replaceindividual cores for enhancedserviceability. Maintenance is alsosimplified since AMOCS is isolatedfrom the engine compartment.

• U-joints. Are lifetime lubricated,leaving the slip joint as the only driveline component needing grease.

• Lube Points. Are centralized inaccessible locations. Fuel fill is locatedon the left side. Both lube points andfuel fill are accessible from groundlevel, making lube and fuel servicequicker and easier.

• Swing-Out Doors. On both sides ofthe engine compartment provide easyaccess to the engine oil dipstick andfiller spout, S•O•SSM port, fuel filters,air conditioner compressor, engine oilfilters, alternator, starting receptacle, airfilter service indicator, coolant fill andether starting aid. The disconnect switchand diagnostic connector are located onrear platform.

• Hinged Doors. In the platform provideaccess to the hydraulic tank fill, lift andtilt and steering filters. Transmissionsight glass and filler spout are servicedfrom the hitch area.

• Case Drain Filters. Protect the hydraulicsystem from contamination and areconveniently located behind the cabin the service platform.

• Batteries. Sit in a built-in battery boxand are accessible through tread plateson the right platform.

• Shock Resistant Lights. Are replaceableby hand, not requiring the use of any tools.

• Cab Support Bracket. Improves accessunder the cab and is conveniently storedbehind the cab.

• Caterpillar Monitoring System (EMS-III).Provides operators and service technicianswith diagnostic information on themachine’s major components andsystems. It also allows for flashablesoftware using a laptop and ET insteadof replacing a chip that contains thenew software.

• Diagnostic Connector. Enables quickevaluation of 11 starting and chargingfunctions.

16

Maintenance and ServiceabilityEasier maintenance and enhanced serviceability give you more time in the pile.

17

Engine

Engine Model Caterpillar 3456 EUIGross Power 388 kW 520 hpFlywheel Power 354 kW 475 hpGross Power - ISO 3046-2 388 kW 520 hpNet Power - ISO 9249 354 kW 475 hpNet Power - EEC 80/1269 354 kW 475 hpBore 140 mm 5.5 inStroke 172 mm 6.8 inDisplacement 15.8 L 964 in3

• These ratings apply at 1,900 rpm when tested under thespecific standard conditions for the specified standard.

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

• Net power advertised is the power available when theengine is equipped with alternator, air cleaner, mufflerand hydraulic fan drive.

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

• Direct-electric, 24-volt starting system with 100 ampalternator and four high performance maintenance-freebatteries with 750 cold cranking amps.

GrossNet

1600 1800 200014001000 1200

2800

1000

1200

1400

1600

1800

2000

2200

2400

2600

400

350

300

250

200

150

100

290

250

270

230

210

190

Engine Speed (RPM)

2066

1919

1771

1624

1476

1328

1181

1033

886

738

536

469

402

335

268

201

134

.476

.443

.411

.344

.377

.312

Engi

ne P

ower

(Bhp

)En

gine

Tor

que

(ft• lb

)

Engi

ne T

orqu

e (N

• m)

Engi

ne P

ower

(kW

)

BSF

C (lb

/Bhp

-hr)

BSF

C (g

m/k

W-h

r)

Operating Specifications

Operating Weight 50 183 kg 110,634 lbRated Payload 11.4 tonnes 12.5 tons

Transmission

Forward 1 6.8 kph 4.2 mphForward 2 11.9 kph 7.4 mphForward 3 20.7 kph 12.8 mphForward 4 35.4 kph 22 mphReverse 1 7.7 kph 4.8 mphReverse 2 13.5 kph 8.4 mphReverse 3 23.5 kph 14.6 mph

• Travel speeds based on two percent rolling resistance and35/65-33 tires in converter drive.

Forward 1 Lock-up disabled Forward 2 12.3 kph 7.7 mphForward 3 21.9 kph 13.6 mphForward 4 38.6 kph 24.0 mphReverse 1 7.9 kph 4.9 mphReverse 2 14.1 kph 8.8 mphReverse 3 25.1 kph 15.6 mph

• Travel speeds based on two percent rolling resistance and35/65-33 tires in direct drive.

Loader Hydraulic System

Main hydraulic system output at 2010 rpm and 6900 kPa (1001 psi) 492 L/min 130 gal/minRelief valve setting 31 000 kPa 4,500 psiCylinders, double acting:lift, bore, and stroke 220 � 911 mm 8.7 � 35.9 inCylinder, double acting: tilt,bore, and stroke 220 � 1770 mm 8.7 � 69.7 inPilot system, gear-type pump output at 2010 rpm and 2500 kPa (363 psi) 76 L/min 20.1 gal/minRelief valve setting (low idle) 2400 kPa 348.1 psi

Hydraulic cycle time - Raise 9.4 SecondsHydraulic cycle time - Dump 2.4 SecondsHydraulic cycle time - Lower,empty, float down 3.8 SecondsTotal Hydraulic Cycle Time 15.6 Seconds

• With SAE 10W oil at 66° C (150° F).

18 988G Wheel Loader specifications

Cab

Cab - ROPS/FOPS Meets SAE and ISOstandards.

Sound Performance Meets ANSI, SAE and ISOstandards.

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

• Standard air conditioning system contains environmentallyfriendly R134a refrigerant.

• ROPS meets SAE J1040 APR88 and ISO 3471:1994 criteria.

• FOPS meets SAE J231 JAN81 and ISO 3449:1992 Level IIcriteria.

• The operator sound exposure Leq (equivalent sound pressurelevel) measured according to the work cycle proceduresspecified in ANSI/SAE J1166 OCT98 is 77 dB(A), for the caboffered by Caterpillar, when properly installed, 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 JUN86 mid-gear-movingoperation is 81 dB(A).

• The sound power level is 115 dB(A) measured according tothe dynamic test procedure and conditions specified in ISO6395:1988/Amd. 1:1996 for a standard machine configuration.

• For “CE” marked configurations, the labeled sound powerlevel is 113 dB(A) measured according to the testprocedures and conditions specified 2000/14/EC.

Brakes

Brakes Meet SAE ISO 3450:1996

Buckets

Bucket Capacities 6.3 to 7.0 m3 8.2 to 9.2 yd3

Max. Bucket Capacity 7 m3 9.2 yd3

Service Refill Capacities

Fuel tank - standard 679 L 179.4 galCooling System 103 L 27.2 galCrankcase 60 L 15.9 galTransmission 70 L 18.5 galDifferentials and final drives 186 L 49 gal- frontDifferentials and final drives 186 L 49 gal- rearHydraulic system (factory fill) 470 L 124.2 galHydraulic system (tank only) 267 L 70.5 gal

Axles

Maximum single-wheel rise and fall 568 mm 22.4 in

• Fixed front, oscillating rear ±13°.

Steering

Total steering angle 86°Steering Meets SAE and ISO

standards.

• Full hydraulic, load-sensing steering system meetsSAE J1511 FEB94 and ISO 5010:1992 specified standards.

• Center point frame articulation.

• Front and rear wheels track.

19988G Wheel Loader specifications

Operation/Bucket Specifications

Straight Rock Spade Rock Gen. Purpose H.D. Quarry High Abrasion

Teeth & Teeth & Teeth & Teeth & Teeth & Teeth &Segments Segments Segments Segments BOCE Segments Segments

† Static tipping load and operating weight shown are based on standard machine configuration with 35/65-33, 36 PR (L-4) tires,full fuel tank, coolant, lubricants and operator.

†† Measured 102 mm (4.0"): behind tip of cutting edge with bucket hinge pin as pivot point in accordance with SAE J732C.

Note: Specifications and ratings conform to all applicable standards recommended by the Society of Automotive Engineers (SAE). SAE Standards J732C JUN92 and J742 FEB85 govern loader ratings, denoted in the text by (§).

Rated capacity (§) m3 6.3 6.4 6.6 6.9 7.0 6.4 6.4yd3 8.2 8.33 8.7 9.0 9.2 8.33 8.33

Struck capacity (§) m3 5.2 5.3 5.5 5.7 5.9 5.3 5.3yd3 6.8 6.9 7.2 7.5 7.7 6.9 6.9

Operating load at rated capacity kg 11 340 11 340 11 340 11 340 11 340 11 340 11 340lb 25,000 25,000 25,000 25,000 25,000 25,000 25,000

Width (§) mm 3800 3800 3900 3980 3729 3800 3926ft/in 12'6" 12'6" 12'10" 13'1" 12'3" 12'6" 12'11"

Dump clearance at full lift and45° discharge. With teeth*: mm 4198 3971 3971 3971 — 3949 3941

ft/in 13'9" 13'0" 13'0" 13'0" — 12'11" 12'11"Bare (§): mm 4451 4246 4249 4249 4304 4253 4245

ft/in 14'7" 13'11" 13'11" 13'11" 14'1" 13'11" 13'11"Reach at full lift and 45°

discharge. With teeth*: mm 1886 2113 2113 2113 — 2136 2144ft/in 6'2" 6'11" 6'11" 6'11" — 7'0" 7'0"

Bare (§): mm 1698 1622 1662 1656 1846 1626 1623ft/in 5'7" 5'4" 5'5" 5'5" 6'1" 5'4" 5'4"

Reach with boom – leveland bucket level. With teeth*: mm 4173 4494 4494 4494 — 4526 4537

ft/in 13'8" 14'9" 14'9" 14'9" — 14'10" 14'11"Bare (§): mm 3861 3752 3810 3801 4070 3759 3755

ft/in 12'8" 12'4" 12'6" 12'6" 13'4" 12'4" 12'4"Digging depth (§) mm 171 171 171 171 171 191 171

in 6.7 6.7 6.7 6.7 6.7 7.5 6.7Overall length With teeth*: mm 12 240 12 527 12 530 12 530 — 12 594 12 656

ft/in 40'2" 41'1" 41'1" 41'1" — 41'4" 41'6"Bare: mm 11 895 12 185 12 182 12 182 12 105 12 173 12 187

ft/in 39'0" 40'0" 40'0" 40'0" 39'9" 39'11" 40'0"Overall height with bucket at mm 8131 8131 8131 8131 7909 8131 8131

full raise (§) ft/in 26'8" 26'8" 26'8" 26'8" 25'11" 26'8" 26'8"Loader clearance circle with bucket in

carry position. With teeth*: mm 17 556 17 531 17 602 17 684 — 17 599 17 646ft/in 57'7" 57'6" 57'9" 58'0" — 57'9" 57'11"

Bare (§): mm 17 392 17 335 17 454 17 520 17 406 17 393 17 448ft/in 57'1" 56'10" 57'3" 57'6" 57'1" 57'1" 57'3"

Static tipping load straight † kg 33 458 32 810 32 831 32 666 33 109 31 305 31 258lb 73,762 72,334 72,380 72,016 72,993 69,016 68,912

Static tipping load at full kg 29 074 28 710 28 669 28 695 29 029 27 396 27 34635° turn lb 64,097 63,294 63,204 63,261 63,997 60,397 60,287

Static tipping load at full kg 28 022 27 661 27 621 27 646 27 989 26 348 26 29840° turn lb 61,777 60,981 60,893 60,948 61,705 58,087 57,977

Static tipping load at full kg 28 060 27 473 27 484 27 319 27 810 25 968 25 91143° turn (§) lb 61,862 60,568 60,592 60,228 61,310 57,250 57,124

Breakout force †† (§) kN 515.4 436.4 437.2 436.4 463.3 415.2 400lb 115,867 98,107 98,286 98,107 104,154 93,341 89,924

Operating weight † (§) kg 49 671 49 886 49 921 50 079 49 418 51 245 51 333lb 109,506 109,980 110,557 110,405 108,948 112,976 113,170

Rack angle at maximum lift degrees 65 65 65 65 65 65 65

20 988G Wheel Loader specifications

Dimensions vary with bucket. Refer to Operation/Bucket Specifications.

4128 mm(13' 6")

4112 mm(13' 6")

3382 mm(11' 1")

3156 mm(10' 4")

3132 mm(10' 3")

549 mm(22")

4550 mm(14' 11")

2275 mm(7' 6")

978 mm(3' 2")

926 mm(36")

5527 mm(18' 2")

5853 mm(19' 2")

45.7°

55.5°

45°

65°

DimensionAll dimensions are approximate.

mm inches mm inches mm inches kg lb kg lb

35/65R33 (L-4) Michelin XLDD1 3579 140.9 445 17.5 — — — — — —

35/65-33 42 PR (L-5) Bridgestone D-Lug 3541 139.4 544 21.4 –99 –3.9 2259 4980 1310 2888

35/65R33 (L-4) Bridgestone V-Steel N Traction VSNT 3566 140.4 483 19.0 –38 –1.5 664 1464 385 849

35/65R33 (L-5) Bridgestone V-Steel D-Lug VSDL 3566 140.4 498 19.6 –53 –2.1 1257 2772 729 1608

35/65-33 42PR (L-5) General LD 250 Belted 3487 137.3 506 19.9 –61 –2.4 1510 3328 876 1930

875/65R33 (L-4) Goodyear RL-4K Hi Stability* — — — — — — — — — —

35/65R33 (L-5) Goodyear RL-5K 20 20 6S 3574 140.7 508 20.0 –64 –2.5 974 2148 565 1246

35/65-33 42PR (L-5) Goodyear NRL D/L 5A 3574 140.7 508 20.0 –64 –2.5 1646 3628 954 2104

875/65R33 (L-5) Goodyear RL-5K Hi Stability 3574 140.7 508 20.0 –64 –2.5 1486 3276 862 1900

35/65R33 (L-5) Michelin XLDD2 3579 140.9 463 18.2 –18 –0.7 648 1428 376 828

35/65R33 (L-5) Michelin XMINED2 3579 140.9 478 18.8 –33 –1.3 1404 3096 815 1796

Width over tiresGround

clearance

Change invertical

dimensions

Change inoperating

weight

Changein full

turn statictipping load

• No tire data currently available.

NOTE: In certain applications (such as load-and-carry work), the loader’s productive capabilities might exceed the tires tonnes-km/f (ton-mph)capabilities. Caterpillar recommends that you consult a tire supplier to evaluate all conditions before selecting a tire model.Other special tires are available on request.

Tire Dimensions/Specifications

21988G Wheel Loader specifications

kg lb kg lb

35/65R33 1 Star (L-4) Michelin SLDD1 — — — —

35/65-33 42 PR (L-5) Bridgestone D-Lug 2259 4980 1310 2888

35/65R33 1 Star (L-4) Bridgestone V-Steel N 664 1464 385 849Traction VSNT

35/65R33 1 Star (L-5) Bridgestone V-Steel 1257 2772 729 1608D-Lug VSDL

35/65-33 42 PR (L-5) General LD 250 Belted 1510 3328 876 1930

875/65R33 2 Star (L-4) Goodyear RL-4K Hi Stability* — — — —

35/65R33 1 Star (L-5) Goodyear RL-5K 20 20 6S 974 2148 565 1246

35/65-33 42PR (L-5) Goodyear NRL D/L 5A 1646 3628 954 2104

875-65R33 2 Star (L-5) Goodyear RL-5K Hi Stability 1486 3276 862 1900

35/65R33 1 Star (L-5) Michelin XLDD2 648 1428 376 828

35/65R33 – (L-5) Michelin XMINED2 1404 3096 815 1796

Supplemental Specifications

Change in Operating Weight Change in Full Turn

Static LoadTires:

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

Tinted glassTransmission gear (indicator)Wet-arm wiper/washers (front and rear)

Intermittent front wiper

Power TrainBrakes, full hydraulic, enclosed, wet multiple disc servicebrakesCase drain filtrationDemand fanEngine, Cat 3456 EUI Direct Injected Diesel and ADEM IIIcontrollerFuel priming aidParking brakePrecleaner, engine air intakeRadiator, Advanced Modular Cooling System (AMOCS)Separated cooling systemStarting aid (ether) manual/automaticThrottle lockGuard, three piece transmissionTorque converter, impeller clutch with rimpull controlsystemTransmission, planetary, auto shift with 4F/3R speed rangecontrol

Other Standard EquipmentAutomatic bucket tilt/lift kickouts, electronically adjustablefrom cabCab tilt supportCounterweightDoors, service access (locking)Engine, crankcase, 500 hour interval with CH4 oilGround level fuel fillHitch, drawbar with pinHydraulic oil coolerLower cab coverMuffler (under hood)Oil sampling valvesStairway, left side rear accessVandalism protection caplocksVenturi stack

Tires, Rims and WheelsAn allowance for tires is included in the base machine price.Tire selections are shown in the Tire/SupplementalSpecifications list on pages 20-21.

AntifreezePremixed 50 percent concentration of extended life coolantwith freeze protection to –34°C (-29°F)

ElectricalAlarm, back-upAlternator (100-amp)Batteries, maintenance-freeDeutsch terminal connectorsDiagnostic connector

Starting and charging systemElectrical converter, 12-voltElectrical system, 24-voltLighting system, Halogen

(Front and Rear)Starter, electric (heavy-duty)Starter receptacle for emergency start

Operator EnvironmentAir ConditionerCab, sound-suppressed, pressurized

Internal four-post rollover protective structure(ROPS/FOPS)Radio ready for (entertainment) includes antenna,speakers and converter (12-volt 50-amp)

Cigar lighter and ashtray Coat hookElectro-hydraulic tilt and lift controlsHeater and defrosterHorn, electricLights, (interior cab)Lunchbox and beverage holdersLoose Material ModeMonitoring system (Caterpillar Monitoring System [EMS-III])

Action alert system, three categoryInstrumentation, Gauges:

Engine coolant temperatureFuel levelHydraulic oil temperatureTorque converter temperature

Instrumentation, Warning Indicators:Axle oil temperature (front/rear)Brake oil pressureCoolant flow statusElectrical system, low voltageEngine oil pressureEngine overspeedHydraulic filter statusParking brake statusSteering oil pressureTransmission filter status

Mirrors, rearview (exterior mounted)Seat (cloth), Cat Comfort, air suspensionSeat belt, retractable, 76 mm (3 in) wideSTIC control system with steering lockTilt and lift control system lock

22 988G Wheel Loader specifications

23988G Wheel Loader specifications

Optional EquipmentOptional equipment and customized attachments may vary. Consult your Caterpillar Dealerfor specifics.

Heater, engine coolant, 220-voltHigh ambient coolingHydraulic, three valveLock-up clutchNo-SPIN differential, rear onlyOil change, high-speedPayload Control System (PCS)Rear intermittent wiperRear chain clearanceRide controlRight-hand stairwayRoading fenders, front and rearRoof, extendedSecondary steeringSound suppression, exteriorSteel mill configuration (Custom)Tires

Auto LubeAuxiliary lightsAxle oil-coolersBlock handler configuration (Custom)BucketsBulk Loader (Custom)Directional lightsEngine Jake BrakeExtended Life Coolant –50°C (–58°F)Forestry configuration (Custom)Fuel, fast fillFuel, heaterFuel, fast fill and heaterGuards

CrankcaseSteering cylinders

Heater, engine coolant, 120-volt

R

For more complete information on Cat products, dealer services, and industry solutions, visit us on the web at www.CAT.com

© 2003 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.

AEHQ5388-03 (10-03)

Replaces AEHQ5388-02

988G Wheel Loader