Caterpillar 938G II
Maintenance schedule, common problems & OEM parts breakdown
The Caterpillar 938G Series II is a mid-size wheel-type loader built roughly from 2003 to 2008, sized for general construction, aggregate, and municipal loading work. It runs one engine across its entire production run: the Cat 3126B ATAAC, a turbocharged, air-to-air aftercooled inline-six diesel with a HEUI fuel system and ADEM III electronic controls, rated 119 kW (160 hp) net at 2200 rpm and up to 134 kW (180 hp) maximum flywheel power. Operating weight runs roughly 13,450-14,700 kg (29,650-32,400 lb) depending on bucket, tires, and options selected. It followed the original 938G (1998-2003), itself a successor to the 938F (1995-1997), and was replaced by the 938H starting around 2008. Cat offered the Series II with general-purpose and universal buckets from about 2.3 to 3.0 m3 (3.0 to 3.9 cu yd), a high-lift linkage, several tire compounds, pallet forks, a material-handling arm, and factory waste-handling and corrosion-resistance packages.
Series II updated the base 938G with a three-pattern electronic transmission shift selector, on/off/auto ride control, a Contour air-suspension seat, and a swing-out cooling package covering the radiator, hydraulic oil cooler, and air-conditioning condenser for easier cleanout on dusty or waste-handling sites. The engine, powershift transmission architecture, and axle package carried over from the earlier 938G largely unchanged, so the core driveline is well understood by technicians who worked on either generation. In the used and parts market, the 938G Series II remains a common mid-size loader with a large working population, a HEUI-fed powershift driveline that is well documented for diagnosis, and resale value that tracks maintenance discipline more than raw hours; consistent oil-change intervals on the 3126B are repeatedly cited as the single biggest factor separating high-hour survivors from problem machines.
Below: full specifications, fluids & capacities, the factory service schedule, common service parts, verified fault codes, what owners discuss, attachment guidance, the complete assembly directory, and a serial-number reference. Complete parts lists with full OEM part numbers, exploded diagrams, quantities, and fitment data are available free in Heavy Parts AI.
Caterpillar 938G II specifications
Engine
| Engine model | Cat 3126B ATAAC diesel: HEUI (hydraulically actuated, electronically controlled unit injection) fuel system, turbocharged, air-to-air aftercooled, four-stroke, six-cylinder. One engine offering documented across the full 938G Series II production run (no mid-life engine change found). |
| Gross / maximum flywheel power | 134 kW (180 hp) at 1800 rpm |
| Net / rated flywheel power | 119 kW (160 hp) at 2200 rpm, per ISO 9249 and EEC 80/1269 test standards |
| Maximum torque | 839 Nm (619 lb-ft) at 1400 rpm; total torque rise 62% |
| Displacement | 7.2 L (439 cu in); bore 110 mm (4.33 in) x stroke 127 mm (5.00 in) |
| Cylinders | 6, inline, cross-flow head with three valves per cylinder |
| Emissions tier | Meets EU Stage II (97/68/EC) per the European-market spec sheet; North American product listings for this engine cite EPA Tier 2 certification |
Weights
| Operating weight | 13,979-14,363 kg (30,818-31,666 lb) depending on bucket and ground engaging tool choice; factory literature quotes a 14,000-14,700 kg range for the standard machine |
| Static tipping load, straight | 10,656-11,444 kg (23,500-25,230 lb) depending on bucket/GET configuration |
| Static tipping load, full articulation (37 deg) | 9,201-9,939 kg (20,285-21,914 lb) depending on bucket/GET configuration |
Dimensions
| Overall length | 7.18-7.55 m (23'7" -24'9") depending on bucket and ground engaging tool choice |
| Overall height, top of cab (standard, bucket lowered) | 3.31 m (10'10") |
| Overall height, bucket at full raise | 5.14-5.28 m (16'10"-17'4") on the standard lift arrangement; the high-lift arrangement adds about 0.42 m (16.6 in) |
| Width over tires | 2.55-2.57 m (8'4"-8'5") depending on tire choice; tread width is 2.02 m (6'8") on all tire options |
| Wheelbase | 3.05 m (10'0") |
| Ground clearance | 0.41-0.47 m (16-18 in) depending on tire choice, about 0.42 m (16.5 in) on standard tires |
| Minimum turning radius, over tire | 5.48 m (18'0") |
| Loader turning radius, bucket in carry position | 5.96-6.09 m (19'7"-20'0") depending on bucket/GET |
Performance
| Maximum travel speed, forward (4th gear) | 38.8 km/h (24.1 mph) |
| Forward speeds, gears 1-3 | 7.6 km/h (4.7 mph), 13.4 km/h (8.3 mph), 23.3 km/h (14.5 mph) |
| Reverse speeds, gears 1-3 (top reverse gear) | 7.6 km/h, 13.4 km/h, 23.3 km/h (4.7, 8.3, 14.5 mph); transmission has three reverse speeds versus four forward |
| Breakout force | 101-126 kN (22,700-28,300 lbf) depending on bucket and ground engaging tool configuration |
| Hydraulic cycle time | Raise 6.0 sec, dump 1.4 sec, lower (empty, float down) 2.8 sec; total cycle 10.2 sec |
| Steering angle | 40 degrees each direction, center-point articulated frame, load-sensing hydraulic steering |
Service capacities (summary)
| Fuel tank | 254 L (67.1 US gal) |
| Hydraulic system, including tank | 90 L (23.8 US gal) total; hydraulic tank alone holds 76 L (20.1 US gal) |
| Engine oil (crankcase) | 31 L (8.2 US gal) |
| Cooling system | 48 L (12.7 US gal) |
| Transmission | 30 L (7.9 US gal) |
| Differentials and final drives | 30 L (7.9 US gal) front, 32 L (8.5 US gal) rear |
Values vary by configuration, region, and serial range — confirm against your machine before planning transport or lifts.
938G II fluids & capacities
| System | Capacity | Recommended fluid |
|---|---|---|
| Engine crankcase (with filter) | 31 L (8.2 US gal) | Cat DEO (Diesel Engine Oil), SAE 15W-40 for warm climates, API CH-4 rated; SAE 10W-30 recommended in cooler ambient temperatures per Cat viscosity-by-climate guidance |
| Cooling system | 48 L (12.7 US gal) | Cat ELC (Extended Life Coolant), factory-fill, extended change interval versus conventional antifreeze |
| Fuel tank | 254 L (67.1 US gal) | Diesel fuel meeting engine emissions requirements for the 3126B ATAAC engine; use low-sulfur fuel per engine rating |
| Transmission (power train) | 30 L (8.0 US gal) | Cat TDTO (Transmission/Drive Train Oil), SAE 30 standard grade; Cat Cold-Weather TDTO (synthetic blend, SAE 0W-20) for cold-climate operation |
| Hydraulic system (incl. tank) | 90 L (23.8 US gal) | Cat TDTO family fluid shared with the power train circuit; viscosity grade selected by ambient temperature per Cat guidance |
| Front axle/differential (incl. final drives) | 30 L (8.0 US gal) | Cat TDTO (Transmission/Drive Train Oil), grade selected by ambient temperature |
| Rear axle/differential (incl. final drives) | 32 L (8.5 US gal) | Cat TDTO (Transmission/Drive Train Oil), grade selected by ambient temperature |
| Grease (all fittings) | Spec only, no system fill volume | Cat Advanced 3Moly Grease (lithium-complex base with 3% molybdenum disulfide), standard factory-fill for -20 to 40 C (-4 to 104 F) service; Cat MPGM (Multipurpose Grease) as an alternate all-purpose grease |
Capacities are refill values from factory literature — always fill to the dipstick/sight gauge, not the number.
Caterpillar 938G II maintenance schedule
| Service interval | Tasks |
|---|---|
| Every 10 h |
|
| Every 250 h |
|
| Every 500 h |
|
| Every 1,000 h |
|
| Every 2,000 h |
|
| Every 6,000 h |
|
| Every 12,000 h |
|
Servicing the 938G II beyond the schedule
Predictive Maintenance & Fluid Analysis
Run S·O·S oil sampling on the engine, transmission, and both axle housings on the factory schedule; wear-metal trends catch a failing HEUI injector, worn high-pressure oil pump, or transmission clutch pack before they cause a breakdown. Pull stored MID 081 fault codes at every service interval; a drifting transmission oil-temperature sensor is a documented cause of harsh or delayed shifts on this platform. Track Extended Life Coolant condition with Level 1 samples instead of waiting for visible trouble at the radiator or oil cooler.
Corrective & Common Repairs
The 3126B's HEUI system is the top repair driver: worn injectors and a tired high-pressure oil pump show up as hard starting, smoke, or a knock as injection timing drifts. Transmission harshness usually traces to a bad oil-temperature sensor or corroded clutch-solenoid wiring rather than the clutch packs themselves; check connectors before condemning parts. A worn center-hinge bearing or missing pin sleeve causes front-fork bounce. Sluggish steering often means aerated hydraulic fluid from a suction-side leak, not a failing pump.
Overhaul & Rebuild Points
Engines on a disciplined 500-hour oil-change interval routinely reach very high hour totals before major work; skipped intervals are the leading cause of early 3126B top-end wear. Turbocharger shaft seals wear on high-hour units, showing up as oil pulled into the intake and blue smoke under load. The articulation bearing is not field-adjustable: once play develops, plan on full bearing and pin-sleeve replacement. Years of rough directional shifting wear or warp transmission clutch plates and springs, eventually calling for a clutch-pack rebuild.
Seasonal & Environment Servicing
Switch to Cat TDTO cold-weather blend in the transmission and axles, and drop to a lighter engine oil viscosity, before winter operation in cold climates; the powershift and hydraulic-steering circuits are both sensitive to cold, thick fluid on startup. In dusty aggregate or demolition work, service the turbine precleaner and check the air-filter restriction indicator more often than the standard 250-hour interval. Machines built with the waste-handling or corrosion-resistance packages still need the added guarding and seals inspected each season, not just the base machine.
938G II fault codes & troubleshooting
| Code | Meaning | Likely cause | What to do |
|---|---|---|---|
| CID 0070 FMI 03/04 (MID 081) | Parking brake limit switch circuit reading voltage above or below the normal range. | Open or short in the parking brake switch wiring, a corroded connector, or a failed switch. | Inspect switch harness and connector for damage or corrosion, test switch continuity, repair or replace as needed, then clear the code and confirm with the service tool. |
| CID 1401 FMI 05 (MID 081) | Forward/low-range clutch modulating valve solenoid current below normal, an open circuit. | Open solenoid coil, damaged wiring or connector at the transmission valve body, or a driver fault in the power train ECM. | Check solenoid coil resistance and harness continuity from the ECM to the valve, repair the connector or replace the solenoid, and verify clutch fill pressure after the repair. |
| CID 1403 FMI 05 (MID 081) | Reverse clutch modulating valve solenoid current below normal, an open circuit. | Same failure pattern as the forward-clutch circuit: open coil, chafed harness, or a bad connector pin at the transmission. | Test the reverse solenoid coil resistance and wiring, repair or replace as needed, then recheck directional shift quality. |
| CID 0177 FMI 03/04 (MID 081) | Transmission oil temperature sensor signal voltage above or below normal. | Failed or drifting temperature sensor, corroded connector, or damaged sensor wiring. | Check sensor resistance against the temperature/resistance chart and inspect wiring; replace the sensor if out of spec. An erratic reading here is a known cause of harsh or delayed shifts. |
| CID 0041 FMI 03/04 (MID 081) | Shared sensor supply voltage circuit reading above or below normal. | Short to power or ground on the sensor supply circuit, or a failed sensor pulling the shared supply out of range. | Disconnect sensors fed by this supply one at a time to isolate the fault, repair the short or replace the offending sensor, then clear and retest. |
| CID 0149 FMI 03/05/06 (MID 081) | Ride control solenoid valve circuit voltage or current fault, or a grounded circuit. | Open or shorted solenoid coil, damaged harness, or a sticking/failed ride control valve. | Check solenoid coil resistance and wiring, inspect the valve for sticking, and replace the solenoid or repair the harness as needed. |
| CID 0672 FMI 01 (MID 081) | Torque converter output speed sensor signal below the normal operating range. | Sensor air gap out of adjustment, a failed speed sensor, or damaged wiring. | Check and reset the sensor air gap to spec, inspect wiring, and replace the sensor if the signal stays out of range. |
| CID 0248 FMI 12 (MID 081) | CAT Data Link communication fault, flagged as a bad device or component on the link. | Damaged data link wiring or connector, a failed module on the link, or lost communication between the engine and power train ECMs. | Check data link wiring and connectors for damage, use the service tool to identify which module dropped off the link, then repair wiring or replace the faulted module. |
| CID 0793/0794 FMI 03/04 (MID 081) | Primary or secondary steering oil pressure switch circuit voltage abnormal. | Failed pressure switch, damaged wiring, or low steering system pressure tripping the switch reading. | Check switch wiring and continuity, verify actual steering pump pressure against spec, and replace the switch if it fails to actuate correctly; treat as safety-critical and inspect the secondary steering system before returning the machine to service. |
Codes and remedies are general guidance for this model family — always confirm with diagnostic tooling and your dealer before major repairs.
938G II attachments & work tools
General Excavation buckets
Slope-floor, shell-tine buckets for bank and excavation duty, rated 2.3 to 3.0 m3 (3.0 to 3.9 cu yd) for this class. Bucket hinges form box sections extending to the cutting edge for twist and impact resistance, with integral spill plates and reinforced rear/side wear plates.
Universal (flat-floor) buckets
Flat-floor buckets in the same 2.3 to 3.0 m3 (3.0 to 3.9 cu yd) range, giving easier pile penetration and better fill factor for general loading; not recommended for full-time bank or rock work. Offered plain or with a welded back grading edge for finish-grading capability while still accepting bolt-on adapters and tips.
High Lift arrangement
Factory or field-installed option that increases dump clearance and reach over the standard-lift linkage, at some cost to static tipping load and breakout force. All standard bucket families can be fitted to it, and it can be combined with the third hydraulic valve as one package.
High-dump buckets
Roll-forward, extended-spill buckets for discharging over the sides of high-sided trucks or into hoppers. Suited to stockpile loading, waste-transfer station work, and rehandling light bulk material such as fertilizer, coal or grain.
Pallet forks
Bolt-on fork carriage for palletized and loose material handling, mounted through the same coupler system as the buckets.
Material handling arm
Boom-style attachment with adjustable length and load rating for overhead placement work, such as lowering pipe or beam sections into position on a site; mounts via the standard work-tool coupler.
Quick coupler / mounting system
Standard coupler is a vertical wedge-lock design offering minimal breakout-force loss, automatic wear take-up, and high durability; a pin-lock coupler is offered as an alternate for other-brand tools. Activating the coupler from the cab needs the optional dedicated hydraulic actuation circuit, which also frees the third valve to run auxiliary tools without extra diverter valves. Later parts documentation also lists a shared quick-coupler line spanning this model and its direct successor, so exact coupler compatibility can vary by build date - verify with your dealer.
Ground engaging tools (GET)
Bolt-on cutting edges and end bits come in standard reversible, heavy-duty reversible (roughly 50 percent more wear life), and tungsten-carbide-impregnated abrasion-resistant grades. Bolt-on tooth systems use corner and center strap adapters with a range of tip profiles (penetration, short, long, and heavy-duty variants) plus a heavy-duty retention system to stop pin walking; reversible edge segments are also offered in standard and heavy-duty wear grades.
Hydraulic third valve and joystick arrangement
Optional single-lever joystick combines lift and tilt in one control; a separate third-valve control lever operates hydraulically driven work tools. Both are available factory-installed or as field-installable kits, and an optional forward/neutral/reverse switch can be integrated into the lift lever or joystick.
Ride control
A nitrogen-over-oil accumulator in the lift circuit dampens bucket and lift-arm pitch over rough ground, allowing faster travel with better load retention. Offered with off/on/auto selection; whether it ships standard or optional varies by configuration/market.
Differential options
Limited-slip differentials are available for the front and/or rear axle for traction in mud, water, snow or ice, and a no-spin (locking) rear differential is a separate option; the base axle uses a conventional differential. Whether rear limited-slip ships standard varies by configuration/market.
Waste handling arrangement
Factory package adding extensive guarding and machine modification, including a trash/debris grille, for refuse and demolition duty while preserving access for cleaning and maintenance.
Corrosion resistance arrangement
Factory package protecting vital machine components for harsh corrosive applications such as coastal, marine-adjacent or chemical sites.
Payload control system
Optional in-cab weighing attachment that weighs and accumulates bucket loads with a cab-mounted monitor, used to track load-out accuracy.
Guarding and undercarriage protection
Optional bottom guard, power-train guard, axle seal guards, and vandalism-protection caplocks support rough-site or hostile-environment use; a turbine precleaner, including a trash-rated version, is offered for dusty conditions.
Automatic lubrication system
Optional centralized greasing system delivers grease to chassis points on a timed cycle while the machine works, cutting manual greasing labor and improving grease distribution at bearing surfaces.
All 938G II assemblies by section
Every catalogued assembly group for the Caterpillar 938G II. Open an assembly to preview the parts inside — full OEM part numbers are available in Heavy Parts AI.
Air Inlet And Exhaust System
219-2740 Lines Gp-Air -Custom
| 14***67 | Clamp; (Hose) | 8 |
| 16***74 | Washer | 4 |
| 17***81 | Hose | 1 |
200-7137 Precleaner Gp
| 12***37 | Precleaner As; -Air Cleaner-Air Inlet | 1 |
| 20***37 | Precleaner Group | 1 |
| 20***38 | Precleaner Group | 1 |
Braking System
213-8773 Accumulator Gp-Brake
| 1J***71 | Seal (10.52 Degrees I.D.); Seal-O-Ring -- To Adapter | 1 |
| 21***73 | Accumulator Group-Brake; -Charged | 1 |
| 22***32 | Cap; (Gas Valve) | 1 |
200-1315 Brake Gp-Parking
| 20***15 | Brake Group-Parking | 1 |
| 20***16 | Camshaft | 1 |
| 3B***12 | Lockwasher (3/4") Transfer Gear Case To Frame Mounting | 2 |
229-2441 Control Gp-Parking Brake -Custom
| 14***05 | Cable As-Parking Brake Control | 1 |
| 16***79 | Bolt | 2 |
| 16***81 | Washer | 2 |
219-0181 Lines Gp-Service Brake -Custom
| 10***03 | Kit; (Receptacle) (3-Pin) (Includes Receptacle As & Wedge) | 1 |
| 10***04 | Tee | 1 |
| 13***06 | Valve Group-Accumulator Charging; (Brake) | 1 |
Cooling System
191-1932 Guard Gp-Fan
| 18***25 | Guard Assem. | 1 |
| 18***91 | Bracket Assem. | 6 |
| 18***92 | Plate | 6 |
229-2435 Radiator & Fan Gp -Custom
| 12***07 | Mount As-Resilient | 2 |
| 13***38 | Adapter | 1 |
| 16***76 | Bolt | 6 |
Electrical And Starting System
132-1829 Alarm Gp -Fault
| 10***02 | Kit-Receptacle; (2-Pin)(Engine Sensor Wiring Harness) | 1 |
| 13***29 | Alarm Group; -Overload Warning | 1 |
| 18***35 | Pin-Connector; (16-Ga To 18-Ga) | 2 |
198-4493 Alarm Gp
| 11***99 | Gasket; (Air Conditioner Control) | 1 |
| 13***29 | Alarm Group; -Overload Warning | 1 |
| 15***69 | Plug As-Connector; (2-Pin) | 1 |
221-7626 Alternator Ar-Charging -Custom
| 10***02 | Kit-Receptacle; (2-Pin)(Engine Sensor Wiring Harness) | 2 |
| 10***03 | Kit; (Receptacle) (3-Pin) (Includes Receptacle As & Wedge) | 1 |
| 15***60 | Kit-Connecting Plug; (3-Pin)(Engine Sensor Wiring Harness) | 5 |
201-9419 Alternator Gp-Charging -Custom
| 12***14 | Spacer; (10.05x14.60x18-mm Thk) | 2 |
| 12***96 | Pulley-Alternator | 1 |
| 13***21 | Bolt-Hex Head; (M10x1.5x120mm) | 1 |
3e-7577 Alternator Gp-Charging
| 10***31 | Fan-Alternator; (11-Blade) | 1 |
| 10***32 | Collar; (Alternator) | 1 |
| 10***56 | Diode As; (Alternator) | 1 |
9w-0742 Block Gp-Junction
| 6V***22 | Tube-Heat Shrink; (25.4-mm Dia)(10-M) | 0 |
| 7F***60 | Washer | 6 |
| 8C***58 | Block Group-Junction; (Battery) | 1 |
176-5459 Control Gp-Position -Work Tool
| 15***67 | Plug As-Connector; (3-Pin) | 1 |
| 15***76 | Wedge-Plug Lock; (3-Pin) | 1 |
| 17***59 | Control Group-Bucket Positioner | 1 |
145-8670 Control Gp-Lift Kickout
| 10***03 | Kit; (Receptacle) (3-Pin) (Includes Receptacle As & Wedge) | 1 |
| 14***70 | Control Group-Lift Kickout | 1 |
| 3E***71 | Wedge; (Receptacle Lock) (3 Pin) | 1 |
229-5413 Panel Gp-Circuit Breaker -Custom
| 0S***70 | Cap Screw (5/8" Long) | 2 |
| 10***05 | Kit-Receptacle; (6-Pin)(Display Monitor Harness) | 1 |
| 12***02 | Switch Group-Magnetic; -Starting Motor, Start Relay | 1 |
229-2440 Panel Gp-Circuit Breaker -Custom
| 16***81 | Washer | 3 |
| 20***45 | Panel Group-Circuit Breaker | 1 |
| 22***23 | Bolt | 3 |
183-8597 Sensor Gp-Speed
| 10***02 | Kit-Receptacle; (2-Pin)(Engine Sensor Wiring Harness) | 1 |
| 17***49 | Strap; (Marker) | 1 |
| 18***97 | Sensor Group-Speed; -Transmission Output | 1 |
118-7226 Sensor Gp-Temperature
| 10***03 | Kit; (Receptacle) (3-Pin) (Includes Receptacle As & Wedge) | 1 |
| 11***26 | Sensor Group-Temperature; -Transmission Oil | 1 |
| 3E***71 | Wedge; (Receptacle Lock) (3 Pin) | 1 |
229-2443 Switch Gp-Disconnect -Custom
| 18***88 | Bolt | 2 |
| 18***89 | Washer; (6.4x12.5x1.6-mm Thk) | 4 |
| 19***63 | Nut; (M6x1-Thd) | 2 |
167-0138 Switch Gp-Magnetic
| 15***70 | Kit-Connecting Plug; (2-Pin)(Engine Sensor Wiring Harness) | 1 |
| 16***38 | Switch Group-Magnetic; -Main Relay-Main Power Relay | 1 |
| 3E***62 | Wedge-Plug Lock; (2-Pin) | 1 |
125-1302 Switch Gp-Magnetic
| 01***80 | Lockwasher | 2 |
| 10***02 | Kit-Receptacle; (2-Pin)(Engine Sensor Wiring Harness) | 1 |
| 12***02 | Switch Group-Magnetic; -Starting Motor, Start Relay | 1 |
228-3147 Wiring Gp-Autolube Control -Custom
| 10***03 | Kit; (Receptacle) (3-Pin) (Includes Receptacle As & Wedge) | 1 |
| 10***04 | Kit-Receptacle; (4-Pin)(Start Switch) | 1 |
| 14***55 | Receptacle As | 1 |
201-8416 Wiring Gp-Secondary Steering
| 10***01 | Kit; (Receptacle) (12-Pin) (Includes Receptacle As & Wedge) | 1 |
| 10***03 | Kit; (Receptacle) (3-Pin) (Includes Receptacle As & Wedge) | 1 |
| 11***49 | Cable Assem. | 1 |
Frame And Body
138-1917 Counterweight Gp
| 10***96 | Pin-Keeper | 1 |
| 13***78 | Counterweight | 1 |
| 13***17 | Counterweight Group | 1 |
230-4023 Lubrication Ar-Automatic -Custom
| 00***39 | Adapter-Pipe | 1 |
| 10***72 | Tube Assem. | 1 |
| 10***73 | Tube Assem. | 1 |
164-6798 Lubrication Gp-Automatic -Custom
| 16***98 | Lubrication Group-Automatic; -Custom | 1 |
196-5766 Mounting Gp-Automatic Lube -Custom
| 19***66 | Mounting Group-Automatic Lube; -Custom | 1 |
| 19***68 | Boss Group; (Lift Arm) | 1 |
| 19***72 | Boss Group; (Lever) | 1 |
195-9833 Pin Gp-Hood -Custom
| 12***30 | Pin Assem. (R. H.) | 1 |
| 12***31 | Pin Assem. (L. H.) | 1 |
| 19***21 | Pin As; (Rh) | 1 |
196-5776 Support Gp-Frame -Custom
| 19***76 | Support Group-Frame; -Custom | 1 |
| 2B***04 | Clip (1.062" Long); (1/4 In Id Opening) | 1 |
| 3S***93 | Strap-Cable-To Tie Harnesses Together | 20 |
Hydraulic System
168-1880 Body Gp-Pilot Valve
| 14***26 | Bolt-Socket Head; (M6x1x150-mm) | 2 |
| 14***77 | Adapter | 4 |
| 16***80 | Body Group-Pilot Valve | 1 |
199-3446 Control Gp-Pilot Operated Hyd
| 10***05 | Kit-Receptacle; (6-Pin)(Display Monitor Harness) | 1 |
| 10***06 | Screw-Pan Head; (6-19x0.37-In) | 4 |
| 10***50 | Support Assem. | 1 |
4z-6122 Cylinder Gp-Tilt -Custom
| 14***21 | Head | 1 |
| 16***07 | Seal As-Buffer | 1 |
| 16***17 | Seal-U-Cup | 1 |
148-9562 Handle Gp-Modular
| 14***62 | Handle Group-Modular; -Joystick, 3-Function-Lift, Tilt, Tip W/Downshift | 1 |
| 8T***29 | Pin-Connector; (16-Ga To 18-Ga)(Throttle Position Sensor) | 2 |
188-9625 Hydraulic Ar-3 Valve -Custom
| 15***06 | Arm & Bearing As-Lift | 1 |
| 18***25 | Hydraulic Ar-3 Valve; -Custom | 1 |
| 18***26 | Lines Group-Front; -Custom | 1 |
220-4105 Kickout & Positioner Gp
| 08***21 | Plate | 1 |
| 10***78 | Bracket | 1 |
| 12***24 | Spacer | 1 |
234-5564 Lines Gp-Coupler -Custom
| 23***64 | Lines Group-Coupler; -Custom | 1 |
| 23***66 | Hose As | 2 |
234-5565 Lines Gp-Coupler -Custom
| 08***86 | Clamp | 2 |
| 1A***79 | Capscrew (5/16 - 18 Nc X 1 1/2 Gd5, Hex) | 1 |
| 23***65 | Lines Group-Coupler; -Custom | 1 |
234-2899 Lines Gp-Coupler -Custom
| 08***86 | Clamp | 14 |
| 09***36 | Boss; (M10x1.5-Thd) | 2 |
| 09***66 | Washer; (Hard) (4.5x9x1mm Thk) | 4 |
229-2445 Lines Gp-Front -Custom
| 10***61 | Tube Assem. | 1 |
| 10***62 | Tube Assem. | 1 |
| 10***63 | Tube Assem. | 1 |
233-8765 Lines Gp-Front -Custom
| 11***58 | Plate | 1 |
| 11***75 | Plate | 1 |
| 23***06 | Clip | 2 |
188-9626 Lines Gp-Front -Custom
| 11***58 | Plate | 1 |
| 11***75 | Plate | 1 |
| 18***26 | Lines Group-Front; -Custom | 1 |
188-9627 Lines Gp-Pilot -Custom
| 11***99 | Strip | 1 |
| 18***27 | Lines Group-Pilot; -Custom | 1 |
| 18***28 | Chain; (70m) | 0 |
200-8637 Lines Gp-Pilot
| 16***53 | Hose Assem. | 2 |
| 20***37 | Lines Group-Pilot | 1 |
| 3J***07 | Seal Valve Assembly To; Seal- Tube Assembly To Logic Valve | 2 |
232-5303 Lines Gp-Ride Control -Custom
| 10***06 | Film-Warning; (High Pressure Cylinder) | 1 |
| 10***56 | Plug; (Switch) | 1 |
| 11***99 | Gasket; (Air Conditioner Control) | 1 |
191-2943 Motor Gp-Gear -Hydraulic Fan
| 09***94 | Ring-Retaining | 1 |
| 13***29 | Bolt; (M12x1.75) | 4 |
| 13***30 | Washer; (12.5x18x1.5-mm Thk) | 4 |
147-2038 Pivot Gp-Pilot Valve
| 13***89 | Plate | 1 |
| 14***81 | Spacer | 1 |
| 14***15 | Pin-Adjustment | 2 |
145-2322 Pivot Gp-Pilot Valve
| 13***39 | Washer; (3.2x9x0.5-mm Thk) | 1 |
| 13***89 | Plate | 1 |
| 14***81 | Spacer | 1 |
175-9443 Pivot Gp-Pilot Valve
| 13***39 | Washer; (3.2x9x0.5-mm Thk) | 2 |
| 13***89 | Plate | 1 |
| 14***81 | Spacer | 1 |
206-2749 Plate Gp-Pilot Valve
| 14***56 | Retainer | 3 |
| 14***32 | Plate | 3 |
| 14***50 | Plate As | 1 |
229-2447 Valve & Mtg Gp-Main Control -Custom
| 09***06 | Hose Assem. | 1 |
| 10***70 | Tube Assem. | 1 |
| 12***73 | Valve & Mtg Group-Main Control; -2-Function | 1 |
238-7018 Valve & Mtg Gp-Main Control
| 09***06 | Hose Assem. | 1 |
| 10***70 | Tube Assem. | 1 |
| 14***23 | Connector As. | 1 |
9t-7634 Valve Gp-Check -Load
| 03***27 | Seal-O-Ring; (19.18mm Id) | 1 |
| 10***91 | Seal Kit | 1 |
| 9T***34 | Valve Group-Check; -Makeup | 1 |
9t-3096 Valve Gp-Check -Dead Engine Lower
| 20***02 | Valve Group-Check; (Park Brake Release) | 1 |
| 20***34 | Valve Group-Check; (Park Brake Release) | 1 |
| 3J***07 | Seal Valve Assembly To; Seal- Tube Assembly To Logic Valve | 1 |
180-8585 Valve Gp-Diverter -Quick Coupler
| 10***02 | Kit-Receptacle; (2-Pin)(Engine Sensor Wiring Harness) | 1 |
| 18***85 | Valve Group-Diverter; -Quick Coupler | 1 |
| 18***68 | Valve Group-Solenoid; (Quick Coupler) | 1 |
232-3549 Valve Gp-Main Control
| 10***28 | Valve Group-Relief | 1 |
| 14***42 | Stem-Lift | 1 |
| 14***43 | Stem-Tilt | 2 |
238-7017 Valve Gp-Main Control
| 10***28 | Valve Group-Relief | 1 |
| 18***12 | Valve Group-Relief; -Line | 1 |
| 18***08 | Valve Group-Relief; (Line, Tilt Cyl Rod End Port) | 1 |
232-3595 Valve Gp-Main Control -Custom
| 09***06 | Hose Assem. | 1 |
| 11***55 | Tube Assem. | 1 |
| 14***23 | Connector As. | 1 |
112-1817 Valve Gp-Ball
| 11***17 | Valve Group-Manual; -Ride Control-Hydraulic Lockout | 1 |
| 11***61 | Seal Kit; (Includes Seals, Thrust Ring, Stem And Connectors) | 1 |
| 20***71 | Valve Group-Manual; (Coupler Pin, Lift Arm Lwr Cont) | 1 |
164-2800 Valve Gp-Pilot
| 03***39 | Ring-Retaining | 6 |
| 10***06 | Receptacle Kit; (Includes Wedge And Receptacle Assem.) | 1 |
| 11***34 | Connector | 7 |
137-0266 Valve Gp-Pilot Cartridge
| 11***27 | Orifice | 1 |
| 13***04 | Adapter | 1 |
| 13***66 | Valve Group-Pilot Cartridge; -Lift | 1 |
185-7712 Valve Gp-Relief -Line
| 03***28 | Seal-O-Ring | 1 |
| 13***76 | Seal-O-Ring | 1 |
| 18***12 | Valve Group-Relief; -Line | 1 |
108-6428 Valve Gp-Relief -Main
| 10***28 | Valve Group-Relief | 1 |
| 3K***60 | Seal Pilot Manifold On; Seal To Boom Check Valve Drain | 2 |
| 4T***42 | Spring | 1 |
186-0908 Valve Gp-Relief -Line
| 03***79 | Seal-O-Ring (Id=10.82mm) | 3 |
| 03***27 | Seal-O-Ring; (19.18mm Id) | 2 |
| 03***69 | Nut; (3/8-24-Thd) | 1 |
154-8595 Valve Gp-Shutoff
| 11***17 | Valve Group-Manual; -Ride Control-Hydraulic Lockout | 1 |
| 12***54 | Plate; (6-mm Thk) | 1 |
| 12***56 | Plate; (4-mm Thk) | 1 |
141-1481 Valve Gp-Shuttle
| 12***57 | Valve Group-Shuttle | 1 |
| 14***81 | Valve Group-Shuttle; (Ride Control) | 1 |
125-3657 Valve Gp-Shuttle
| 09***51 | Seal-O-Ring (Id=14.00mm) | 1 |
| 12***57 | Valve Group-Shuttle | 1 |
| 16***49 | Seal-O-Ring; (12.42mm Id) | 1 |
149-2610 Valve Gp-Solenoid -Ride Control
| 10***02 | Kit-Receptacle; (2-Pin)(Engine Sensor Wiring Harness) | 2 |
| 11***43 | Locknut; (5/16-18-Thd) | 2 |
| 14***87 | Coil As; (24-Volt) | 1 |
Implements
206-4316 Arm As-Lift
| 10***37 | Crossmember As | 1 |
| 15***06 | Arm & Bearing As-Lift | 1 |
| 20***16 | Arm As-Lift | 1 |
2q-7890 Control Gp-Bucket -Custom
| 09***67 | Washer; (22x60x8-mm Thk) | 6 |
| 10***37 | Crossmember As | 1 |
| 10***59 | Lever Assem. | 1 |
233-8764 Lift Ar-High -Custom
| 10***03 | Kit; (Receptacle) (3-Pin) (Includes Receptacle As & Wedge) | 1 |
| 13***37 | Counterweight Group-Rear; (562kg) | 1 |
| 13***55 | Cylinder Group-Tilt | 1 |
Machine Arrangement
215-6224 Protection Ar-Corrosion -Custom
| 12***31 | Control Group-Parking Brake | 1 |
| 12***07 | Baffle | 1 |
| 19***33 | Terminal Connector; W/Nuts And Washers, Ground, Pin Group-Hood; -Custom | 1 |
Operator Station
229-2436 Air Conditioner Ar -Custom
| 11***93 | Plate; (Instruction) (On Right Side Behind Cab Door) | 1 |
| 18***42 | Air Conditioner Group; -Custom | 1 |
| 19***69 | Lines Group-Air Conditioner | 1 |
189-9942 Air Conditioner Gp -Custom
| 11***99 | Gasket; (Air Conditioner Control) | 1 |
| 18***74 | Heater Group-Cab | 1 |
| 18***42 | Air Conditioner Group; -Custom | 1 |
216-9818 Compressor Gp-Refrigerant
| 14***01 | Cover-Dust; (Rear) | 1 |
| 15***00 | Bolt; (M10x1.5x54.25-mm) | 1 |
| 16***72 | Compressor Group-Refrigerant; -Air Conditioner | 1 |
163-0872 Compressor Gp-Refrigerant
| 10***02 | Kit-Receptacle; (2-Pin)(Engine Sensor Wiring Harness) | 1 |
| 11***69 | Valve Group-Relief; (Refrigerant Compressor) | 1 |
| 16***72 | Compressor Group-Refrigerant; -Air Conditioner | 1 |
230-3304 Lines Gp-Air Conditioner -Custom
| 17***54 | Plate Assem. | 1 |
| 1P***56 | Plate | 1 |
| 20***03 | Clip | 1 |
198-2769 Lines Gp-Air Conditioner
| 06***51 | Clamp | 2 |
| 15***85 | Hose Assem. | 1 |
| 17***54 | Plate Assem. | 1 |
Power Train
190-2899 Case & Parts Gp-Planetary
| 12***23 | Bracket Assem. | 1 |
| 14***31 | Shim Pack; (Includes 19-Shims)(Includes 19 Shims) | 1 |
| 14***28 | Valve-Relief; (Torque Converter Inlet) | 1 |
230-3664 Clutch Gp
| 11***71 | Piston | 2 |
| 20***05 | Gear As; (38 Teeth) | 1 |
| 23***60 | Shaft As | 1 |
197-3260 Clutch Gp
| 10***36 | Ring-Retaining | 2 |
| 11***71 | Piston | 1 |
| 17***39 | Shaft Assem. | 1 |
230-3665 Clutch Gp
| 11***71 | Piston | 2 |
| 23***61 | Shaft As | 1 |
| 23***63 | Gear; (51-Teeth) | 1 |
214-9065 Cover Gp-Shipping
| 21***65 | Cover Group-Shipping | 1 |
| 2D***94 | Gasket | 4 |
| 4M***89 | Seal (4.109" Inside Diameter) | 1 |
204-9602 Input Gp-Transmission
| 20***11 | Gear; (43 Teeth) | 1 |
| 20***13 | Gear; (34 And 56 Teeth) | 1 |
| 20***02 | Input Group-Transmission | 1 |
170-1857 Output Gp-Transmission
| 10***12 | Drum | 1 |
| 14***47 | Cage-Bearing | 1 |
| 16***62 | Yoke-Brake | 1 |
8e-0416 Pump Gp-Transmission
| 2J***50 | Ring-Retaining | 1 |
| 4B***65 | Ball Bearing | 1 |
| 6I***09 | Gear; (72 Teeth) | 1 |
6y-4614 Pump Gp-Transmission
| 3T***94 | Bearing-Sleeve | 2 |
| 5H***52 | Seal 5.73 In. (14.55 cm)Inside Dia. | 1 |
| 5M***87 | Dowel (Part Of 1p***81 Assem.) | 2 |
204-1285 Torque Converter Gp
| 06***43 | Ring-Snap | 1 |
| 12***80 | Ball Bearing | 1 |
| 1T***21 | Ring-Seal | 1 |
201-3265 Transmission Ar
| 17***57 | Output Group-Transmission | 1 |
| 19***99 | Case & Parts Group-Planetary | 1 |
| 19***60 | Clutch Group; (1st & 3rd) | 1 |
229-2444 Transmission Ar -Custom
| 13***09 | Tube-Heat Shrink; (32-mm Dia)(16-cm) | 0 |
| 13***10 | Tube; (12-cm) | 0 |
| 15***40 | Grease-Dielectric | 1 |
216-5338 Valve Gp-Modulating
| 14***44 | Coil Assem. | 1 |
| 16***08 | Washer; (13.03x25.4x2.38-mm Thk) | 1 |
| 16***24 | Nut-Self-Locking; (1/2-28-Thd) | 1 |
201-3322 Valve Gp-Relief
| 11***50 | Cover | 1 |
| 17***66 | Body | 1 |
| 17***68 | Spool As | 1 |
200-2049 Valve Gp-Transmission Control
| 11***26 | Sensor Group-Temperature; -Transmission Oil | 1 |
| 20***49 | Valve Group-Transmission Control | 1 |
| 20***50 | Manifold; (Transmission Control Valve) | 1 |
200-2048 Valve Gp-Transmission Control
| 10***02 | Kit-Receptacle; (2-Pin)(Engine Sensor Wiring Harness) | 1 |
| 13***00 | Clip; (Tab) | 6 |
| 13***89 | Clip; (Ladder) | 11 |
Service Equipment And Supplies
229-2433 Conversion Gp-Fastener -Custom
| 14***35 | Bolt | 2 |
| 16***75 | Bolt | 2 |
| 16***76 | Bolt | 15 |
218-5536 Conversion Gp-Paint -Custom
| 08***21 | Plate | 1 |
| 09***67 | Washer; (22x60x8-mm Thk) | 6 |
| 10***53 | Plate | 1 |
195-1875 Cover Gp-Protection -Custom
| 19***71 | Lever | 1 |
| 19***72 | Cover | 1 |
| 19***73 | Cap As-Filler | 1 |
229-2434 Plate & Film Gp -Custom
| 13***59 | Plate-Identification; (Engine Stop, Run) | 1 |
| 18***52 | Plate-Hood; (Hood) | 1 |
| 19***14 | Film-Instruction | 1 |
Steering System
212-4266 Lines Gp-Secondary Steering
| 13***24 | Hose Assem. | 1 |
| 13***26 | Hose Assem. | 1 |
| 14***97 | Valve Group-Secondary Steering | 1 |
217-3015 Pump & Motor Gp-Sec Steering
| 11***68 | Gasket | 1 |
| 18***67 | Motor Group-Electric; (Secondary Steering) | 1 |
| 18***69 | Valve Group-Relief; (Secondary Steering) | 1 |
233-2204 Pump & Mtg Gp-Secondary Steer -Custom
| 10***01 | Kit; (Receptacle) (12-Pin) (Includes Receptacle As & Wedge) | 1 |
| 15***60 | Kit-Connecting Plug; (3-Pin)(Engine Sensor Wiring Harness) | 2 |
| 15***69 | Plug As-Connector; (2-Pin) | 1 |
229-2524 Steering Gp-Secondary -Custom
| 10***85 | Hose Assem. | 1 |
| 10***56 | Plug; (Switch) | 1 |
| 11***99 | Gasket; (Air Conditioner Control) | 1 |
141-2597 Valve Gp-Secondary Steering
| 10***10 | Valve-Check; (Steering) | 2 |
| 10***11 | Plug; (5/16-12 Thd) | 2 |
| 14***97 | Valve Group-Secondary Steering | 1 |
938G II serial number reference
The PIN plate sits on the left (highway) side of the machine frame, behind the front tire; a backup number is stamped into the frame nearby and can be hidden under paint. On machines built 2001 and later, the plate shows a full 17-character PIN — the 3-letter prefix and 5-digit sequence used above sit in the last 8 characters. Match the prefix and sequence against dealer build records to pin down exact configuration and build date.
| Prefix | Identifies | Notes |
|---|---|---|
| B9Y | 938G Series II wheel-type loader | One of the earliest serial breaks for the Series II update. Machine serial plate reads B9Y followed by a 5-digit sequence starting at 00001. Fitted with the Cat 3126B ATAAC diesel (electronic ADEM III fuel system), net power about 119 kW (160 hp), flywheel power up to 134 kW (180 hp). |
| RTB | 938G Series II wheel-type loader | Runs alongside B9Y as an early Series II machine prefix, sequence starting at 00001. Same 3126B ATAAC diesel as the rest of the Series II run. Engine, transmission, and torque-converter carry their own separate component serial prefixes distinct from this machine PIN. |
| CRD | 938G Series II wheel-type loader | Mid-run Series II machine prefix, sequence starting at 00001. Same Cat 3126B ATAAC diesel, ADEM III electronic controls, net power about 119 kW (160 hp). |
| PHN | 938G Series II wheel-type loader | Series II machine prefix, sequence starting at 00001, listed on Caterpillar's own parts-lookup system under the 938G II model group. Same 3126B ATAAC diesel as the rest of the run. |
| MSC | 938G Series II wheel-type loader | Later Series II machine prefix, sequence starting at 00001. Exact build-date break not documented in available sources — confirm with dealer using the full PIN. |
Frequently asked questions
What engine powers the Caterpillar 938G II?
The 938G Series II runs the Cat 3126B ATAAC diesel: a turbocharged, air-to-air aftercooled inline-six with a HEUI fuel system and ADEM III electronic controls. It is rated 119 kW (160 hp) net flywheel power at 2200 rpm, with up to 134 kW (180 hp) maximum flywheel power. This is the only engine offered across the Series II production run, distinct from the earlier 938G's 3126 DITA engine.
What is the operating weight of the Caterpillar 938G II?
Operating weight runs roughly 13,450-14,700 kg (29,650-32,400 lb) depending on bucket, tires, and factory options; Cat's own literature gives different baseline figures depending on which standard bucket and configuration is assumed. Treat any single number as a starting point and confirm the exact figure for a given serial number and configuration with your dealer.
What replaced the Caterpillar 938G II?
Caterpillar replaced the 938G Series II with the 938H, introduced around 2008 as part of the H-series small wheel loader update. The 938G Series II (roughly 2003-2008) itself succeeded the original 938G (1998-2003), which followed the 938F (1995-1997); the mid-size 938 loader line continued past the 938H into later K- and M-series generations.
What 938G II owners discuss
What transmission complaints come up most often for the 938G II among people who run one?
Which engine is actually in the 938G II, and what quirks come with it?
Any known hydraulic or steering quirks on the 938G II?
What wears out at the center hinge and front axle over time?
What electrical or sensor problems come up most?
What is the general reliability reputation of the 938G II among people who have actually run one?
What should I check before buying a used 938G II?
Compiled from owner and technician discussions across the industry — experiences vary by serial range and machine history.
Need a specific 938G II part?
Search live OEM part data, check fitment, and cross-reference alternatives with Heavy Parts AI.