Caterpillarwheel tractor-scraperwheel tractor
Caterpillar 637E
Maintenance schedule, common problems & OEM parts breakdown
The Caterpillar 637E is a heavy-duty wheel tractor-scraper designed for high-capacity earthmoving, topsoil handling, and large-scale excavation. This machine class features a tractor unit powered by either a 3408E or 3306 engine, with the scraper unit utilizing a 3306 engine. The configuration typically includes an eight-speed power shift transmission and an optional push-pull arrangement for increased productivity. When fully loaded, the machine can reach a maximum weight of over 190,500 lb (86,400 kg), with a scraper capacity of approximately 31 yd³ (23.7 m³).
Across its production generations, the 637E evolved to integrate electronic controls, such as the EPTC II transmission control and electronically controlled cushion hitches, to improve durability and operator comfort. The machine remains a significant presence in the used equipment market due to its rugged construction and the availability of high-performance components like the 3408E engine. Its ability to handle substantial loads over long distances makes it a preferred choice for fleet managers looking for reliable, large-scale production capabilities in secondary or specialized earthmoving applications.
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 637E specifications
Engine
| Tractor Engine Model | 3408 (standard); 3408E / 3408TA (Series II) |
| Tractor Engine Gross Power | 450 hp (standard); 475 hp (Series II, Gears 1-2); 515 hp (Series II, Gears 3-8) |
| Tractor Engine Net Power | 450 hp (standard/Series II, Gears 1-2); 490 hp (Series II, Gears 3-8) |
| Tractor Engine Displacement | 1098.5 cu in (standard); 1099 cu in (Series II) |
| Scraper Engine Model | 3306 (standard/Series II) |
| Scraper Engine Gross Power | 250 hp (standard); 270 hp (Series II, Gear 1); 475 hp (Series II, Tractor Gears 1-2); 515 hp (Series II, Tractor Gears 3-8) |
| Scraper Engine Net Power | 250 hp (standard/Series II, Gear 1); 247 hp (Series II, SAE J1349) |
| Scraper Engine Displacement | 640.8 cu in (standard); 638 cu in (Series II) |
Weights
| Total Operating Weight - Empty | 112,089.7 lb (standard); 112,670 lb (Series II) |
| Total Operating Weight - Loaded | 187,091 lb (standard); 187,670 lb (Series II) |
| Shipping Weight - Total | 110,686 lb (Series II) |
| Front Axle Weight - Loaded | 91,674.9 lb (standard); 91,958 lb (Series II) |
| Rear Axle Weight - Loaded | 95,416.1 lb (standard); 95,712 lb (Series II) |
Dimensions
| Overall Length | 46.86 ft (standard); 573.5 in (Series II) |
| Overall Width | 12.93 ft (standard); 155 in (Series II) |
| Overall Height | 14.08 ft (standard/Series II) |
| Wheelbase | 28.78 ft (standard); 345.25 in (Series II) |
| Ground Clearance - Maximum | 21.5 in (Series II) |
| Width of Cut | 11.6 ft (standard); 138.25 in (Series II) |
Performance
| Max Speed Forward | 29.9 mph (standard); 34.1 mph (Series II, Gear 8) |
| Max Speed Reverse | 6.2 mph (Series II) |
| Transmission Forward Gears | 7 (standard); 8 (Series II) |
| Rated Payload | 75,001.3 lb (standard); 75,000 lb (Series II) |
| Heaped Capacity | 31 yd³ |
| Struck Capacity | 21.1 yd³ (standard); 21 yd³ (Series II) |
Service capacities (summary)
| Fuel Tank Capacity | 322.3 gal (standard); 335 gal (Series II) |
| Hydraulic Reservoir | 50 gal (Series II) |
| Transmission Fluid Capacity | 33 gal (Series II) |
| Differential Fluid Capacity | 36 gal (Series II) |
| Cooling System Capacity | 33 gal (Series II) |
| Crankcase Oil Capacity | 11.7 gal (Series II) |
| Final Drive Capacity - Each | 7 gal (Series II) |
Values vary by configuration, region, and serial range — confirm against your machine before planning transport or lifts.
637E fluids & capacities
| System | Capacity | Recommended fluid |
|---|---|---|
| Engine Crankcase | 11.7 gal US (45 l) | Cat DEO or Cat DEO-ULS (for Tier 4 engines with aftertreatment); SAE 10W-30 preferred for ambient temperatures between -18°C (0°F) and 40°C (104°F). Use higher viscosity if cold start requirements dictate. |
| Cooling System | 33 gal US (126 l) | Not specified by name in provided documentation. |
| Fuel Tank | Not documented for this exact serial range — verify with your dealer | Not specified by name in provided documentation. |
| Transmission/Powertrain | 33 gal US (127 l) | Cat TDTO; SAE 10W/30/50. |
| Final Drives (each) | 7 gal US (25 l) | Cat TDTO. |
| Differential | 36 gal US (136 l) | Cat TDTO. |
| Hydraulic System and Tank | 190 l (50 gal US) | Cat HYDO Advanced 10 (SAE 10W for cold to moderate temperatures) or Cat HYDO Advanced 30 (SAE 30W for moderate to hot temperatures). |
| Wheel Coolant (each) | 75 l (19.5 gal US) | Not specified by name in provided documentation. |
| Grease | Not documented for this exact serial range — verify with your dealer | Not specified by name in provided documentation. |
Capacities are refill values from factory literature — always fill to the dipstick/sight gauge, not the number.
Caterpillar 637E maintenance schedule
| Service interval | Tasks |
|---|---|
| Every 10 h |
|
| Every 250 h |
|
| Every 500 h |
|
| Every 1,000 h |
|
| Every 2,000 h |
|
Servicing the 637E beyond the schedule
Predictive Maintenance & Fluid Analysis
Utilize Cat S.O.S Services to monitor engine oil, hydraulic fluid, and coolant for contaminants like silicon, sodium, or water. Regular analysis detects wear metals such as iron or copper before catastrophic failure occurs. For the 637E, monitoring hydraulic particle counts (ISO cleanliness) is critical to prevent pump and valve damage. Always verify that any fluid extensions are supported by confirmed oil condition reports from laboratory testing.
Corrective & Common Repairs
Frequent repairs often involve addressing hydraulic leaks in the bowl, apron, or ejector cylinders. Inspect all hydraulic hoses for cracks and abrasion to prevent pressure loss. The 637E's electronic monitoring system provides fault recording via EPTC II; use this data to diagnose transmission or engine issues. Ensure the cushion hitch nitrogen-over-oil accumulators are functioning correctly to prevent excessive road shock from damaging the chassis.
Overhaul & Rebuild Points
Major overhaul milestones include hydraulic oil changes and transmission services at 2,000-hour intervals. Inspect the 3408E or 3306 engine for turbocharger wear and evaluate the condition of oil-cooled pistons and water-cooled liners. During structural rebuild points, check the integrity of the double kingbolt design and inspect all steel castings in the hitch area for fatigue or cracks to ensure long-term chassis stability.
Seasonal & Environment Servicing
In dusty or quarry environments, shorten air filter inspection intervals and clean radiator/oil cooler fins daily. For cold weather operations, utilize the 24-volt electric starting system with the automatic ether starting aid to ensure reliable ignition. In high-heat conditions, monitor the engine oil cooler performance and ensure the laminated thermal shields are intact to protect hoses and wiring from extreme temperature exposure.
637E common service parts
| Part number | Part | Notes | |
|---|---|---|---|
| 1R-0716 | Filter As-Engine Oil | Lubrication service | Check fitment → |
| 8T-6765 | Plug-Pipe | Scheduled service item | Check fitment → |
| 9S-8752 | Nut-Full | Scheduled service item | Check fitment → |
Always confirm against your machine's serial number — cross-check any part in Heavy Parts AI before ordering.
637E fault codes & troubleshooting
| Code | Meaning | Likely cause | What to do |
|---|---|---|---|
| E360 | Engine Coolant Temperature — High | Low coolant level, failed thermostat, or water pump issue | Diagnose cooling system; do not operate until resolved |
| E361 | Engine Coolant Temperature — Very High (Shutdown) | Severe cooling system failure | Perform full cooling system diagnosis; engine shutdown required |
| 110-0 | Engine Coolant Temperature — Above Normal | Low coolant level or thermostat failure | Inspect cooling system, refill coolant, and test thermostat |
| 110-3 | Engine Coolant Temperature Sensor — Voltage High | Open circuit or sensor failure | Check wiring and replace sensor if confirmed faulty |
| 174-3 | Engine Fuel Temperature — Voltage Above Normal | Open circuit in sensor wiring | Inspect harness and replace sensor if necessary |
| 190-8 | Engine Speed — Abnormal Frequency | Speed sensor air gap, sensor failure, or tone ring damage | Check sensor gap and test speed sensor/tone ring |
| 2458-2 | DPF #1 Differential Pressure — Erratic | Plugged pressure ports or failing sensor | Clean pressure ports and test sensor; verify DPF soot load |
| 41-3 | 8-Volt DC Supply — Voltage Above Normal | Short to power on 8V reference circuit | Inspect sensors sharing the 8V supply and isolate fault |
| 41-4 | 8-Volt DC Supply — Voltage Below Normal | Short to ground on 8V reference circuit | Disconnect sensors one at a/time to locate short |
| 2348-9 | SAE J1939 Data Link #2 — Abnormal Update Rate | CAN bus wiring damage or termination fault | Check CAN wiring and measure termination resistance |
Codes and remedies are general guidance for this model family — always confirm with diagnostic tooling and your dealer before major repairs.
637E attachments & work tools
Scraper Bowl & Components
Standard open bowl configurations feature a capacity of approximately 24 yd³ (stuck) to 31 yd³ or 34 yd³ (heaped). Functional components include the apron, ejector, and bail, which are piston-actuated.
Mounting & Hitch Systems
The machine utilizes a cushion-hitch gooseneck design. Advanced versions feature an electronically controlled cushion hitch that locks down for positive control of the cutting edge during loading and dumping.
Hydraulic & Control Arrangements
Systems include hydraulic on-demand fans and high-pressure steering. Optional Sequence Assist and Load Assist are available via Cat Grade attachments to reduce operator effort.
Operational Configurations & Guarding
Push-pull arrangements are available as an option, utilizing a hydraulically actuated bail and cushioned plate. Notable guarding includes draft-arm overflow guards to divert material away from the bowl sides.
Integrated Technology & Attachments
Optional attachments include Product Link™ for remote data viewing and a powered access ladder system. Cat Grade technology is an optional attachment that manages cutting and filling depth.
All 637E assemblies by section
Every catalogued assembly group for the Caterpillar 637E. Open an assembly to preview the parts inside — full OEM part numbers are available in Heavy Parts AI.
Air Inlet And Exhaust System
126-0767 Aftercooler Gp-Water
| 0S***71 | Screw,Cap,Hexagon; Tube Assembly To Turbocharger And Elbow Mounting | 12 |
| 0S***90 | Bolt; (3/8-16x2in)(Clip Thru Spacer To Bracket As) | 4 |
| 0S***19 | Bolt,Machine Gear Retaining Part Of Kit P/N 1w***46 | 2 |
7n-8187 Cartridge Gp-Turbocharger
| 0S***16 | Screw,Cap,Hexagon H Receptacle Mtg; Bolt Brackets To Firewall Assembly | 4 |
| 12***63 | Wheel-Compressor | 1 |
| 1P***20 | Ring-Seal | 1 |
322-7949 Conversion Gp-Air Inlet & Exh
| 12***37 | Muffler Group | 1 |
| 32***49 | Conversion Group-Air Inlet & Exh | 1 |
126-5792 Lines Gp-Air
| 0L***43 | Bolt 63.5 mm (3/8" X 2 1/2" -Cover Assembly To Fender | 1 |
| 0L***52 | Capscrew (3/8 - 16 Nc X 3 1/4 Gd8, Hex) | 3 |
| 0L***70 | Bolt (2-1/4") Filler Tube Assembly To Transfer Drive Case | 3 |
179-7023 Manifold Gp-Exhaust
| 10***01 | Seal As-Exhaust | 4 |
| 10***12 | Spacer; (11.13x19.05x53-mm Thk) | 16 |
| 11***50 | Manifold-Exhaust; (Rear, Lh) | 1 |
126-6237 Muffler Gp
| 12***27 | Support As | 1 |
| 12***37 | Muffler Group | 1 |
| 16***28 | Bracket As | 2 |
4w-1495 Turbocharger Gp
| 1S***95 | Gasket-Turbocharger To Manifold; Gasket Turbocharger To Manifold | 1 |
| 2N***65 | Bolt-High Temperature; (3/8-16x1.75-In) | 4 |
| 2N***66 | Locknut; (3/8-16-Thd)(High Temperature) | 4 |
4w-1434 Turbocharger Gp
| 0S***14 | Bolt (.25" Diameter-.50" Long) | 4 |
| 4W***34 | Turbocharger Group | 1 |
| 4W***35 | Housing-Turbine | 1 |
Basic Engine
7w-6245 Cover Gp-Flywheel Housing
| 0S***66 | Bolt-Pulley To Crankshaft Adapter | 3 |
| 0S***94 | Bolt (1 In. Long 3/8 In. Dia.); Plate Assembly To Support Assembly | 1 |
| 0S***19 | Bolt,Machine Gear Retaining Part Of Kit P/N 1w***46 | 1 |
4n-7378 Air Compressor Gp
| 0S***19 | Bolt,Machine Gear Retaining Part Of Kit P/N 1w***46 | 6 |
| 11***37 | Kit-Piston Ring; (Compressor 5 Ring) | 1 |
| 1W***03 | Plug | 2 |
284-7031 Air Compressor Gp
| 0L***51 | Bolt Starting Engine Fuel Tank Bracket To Diesel Intake Manifold | 5 |
| 12***48 | Seal-Integral | 1 |
| 1F***58 | Nut-Full; (1/2-13-Thd)(Air Lines) | 3 |
4n-1092 Balancer Gp
| 0L***51 | Bolt Starting Engine Fuel Tank Bracket To Diesel Intake Manifold | 4 |
| 1B***82 | Bolt (1.25 In. Long X .313 In. Dia.) | 1 |
| 1W***49 | Shaft-Balance Weight | 1 |
108-1547 Camshaft Gp
| 0S***09 | Bolt (3/4") Filler Tube Assembly To Transfer Drive Case | 2 |
| 10***74 | Gear-Camshaft Drive; (86-Teeth) | 1 |
| 10***47 | Camshaft Group | 1 |
4n-6866 Cover Gp-Cylinder Block
| 0S***94 | Bolt (1 In. Long 3/8 In. Dia.); Plate Assembly To Support Assembly | 12 |
| 23***37 | Seal-Integral | 1 |
| 23***71 | Seal-Integral | 1 |
126-0768 Cover Gp-Front Housing
| 0L***52 | Capscrew (3/8 - 16 Nc X 3 1/4 Gd8, Hex) | 6 |
| 0S***94 | Bolt (1 In. Long 3/8 In. Dia.); Plate Assembly To Support Assembly | 3 |
| 11***21 | Support-Housing; (Rh) | 1 |
4n-8159 Cover Gp-Oil Pan
| 0S***87 | Bolt-Bracket Assembly To Timing Gear | 2 |
| 0S***88 | Bolt,Machine; Hose Assembly Mounting,Hose Assembly To Transmission,And To Torque Converter | 2 |
| 10***72 | Seal-O-Ring; (40.64-mm Id) | 2 |
125-9246 Cover Gp-Valve Mechanism
| 10***88 | Base-Valve Mechanism Cover | 4 |
| 11***84 | Cover-Valve Mechanism | 1 |
| 11***15 | Cover As-Valve | 3 |
1w-5009 Crankshaft As
| 1W***09 | Crankshaft As | 1 |
| 4N***84 | Dowel; (.75 Long) | 1 |
| 7N***91 | Gear-Crankshaft; (80-Teeth) | 1 |
1w-5010 Crankshaft Gp
| 1W***09 | Crankshaft As | 1 |
| 1W***10 | Crankshaft Group; Crankshaft Group | 1 |
| 24***18 | Kit-Crankshaft Bearing | 0 |
110-3779 Cylinder Block As
| 11***20 | Seal-O-Ring; (Mid-Liner) | 8 |
| 11***79 | Cylinder Block As | 1 |
| 14***17 | Seal-O-Ring; (140.20mm Id) | 8 |
109-9009 Cylinder Block Gp
| 10***17 | Stud-Taperlock | 18 |
| 10***09 | Cylinder Block Group | 1 |
| 11***09 | Cylinder Block As | 1 |
143-0040 Cylinder Head As
| 14***40 | Cylinder Head As | 1 |
| 1W***83 | Insert-Valve Seat; (Exhaust)(Standard) | 8 |
| 3B***23 | Core Plug--Flywheel Housing Pinion Shaft Hole | 8 |
143-3614 Cylinder Head As
| 10***94 | Dowel | 2 |
| 14***40 | Cylinder Head As | 1 |
| 14***14 | Cylinder Head As | 1 |
107-7320 Cylinder Head Gp
| 10***20 | Cylinder Head Group | 1 |
| 12***21 | Valve-Exhaust | 8 |
| 12***22 | Valve-Inlet | 8 |
107-7319 Cylinder Head Gp
| 03***27 | Seal-O-Ring; (19.18mm Id) | 2 |
| 06***61 | Seal-O-Ring (Id=40.87mm) | 8 |
| 10***92 | Stud-Taperlock; (3/8-16x3.93in) | 16 |
4p-5893 Damper Gp
| 16***26 | Damper Assem. | 1 |
| 16***00 | Spacer; (131.57mmx163.6mmx8mm Thk) | 1 |
| 1A***03 | Bolt 12.07 cm(4.75 In.) Long | 6 |
9n-0725 Drive Gp-Accessory
| 5P***40 | Seal-O-Ring | 1 |
| 6B***83 | Nut,Plain,Hexagon Lever | 1 |
| 7N***22 | Gear-Compressor Drive; (46-Teeth) | 1 |
7w-4999 Flywheel Gp
| 0S***76 | Bolt 5.08 cm(2 In.) Long | 12 |
| 4D***04 | Washer,Flat Cover Mtg,Accessory Drive | 12 |
| 4N***14 | Gear; (113-Teeth)(Flywheel Starter) | 1 |
126-7281 Gear Gp-Front
| 0S***71 | Screw,Cap,Hexagon; Tube Assembly To Turbocharger And Elbow Mounting | 1 |
| 10***13 | Plate-Retaining | 1 |
| 11***17 | Plate-Thrust | 1 |
4n-3825 Gear Gp-Rear
| 1B***75 | Bolt (" " " ); Bolt ( " " " ) | 4 |
| 4N***25 | Gear Group-Rear; Rear Timing Gear Group | 1 |
| 4W***85 | Gear-Camshaft; (86-Teeth) | 1 |
4n-9680 Governor Gp-Air Compressor
| 2S***23 | Cover As; (Governor) | 1 |
| 4N***80 | Governor Group-Air Compressor | 1 |
| 9M***02 | Kit; (Governor Overhaul) (Includes Cover, Gasket, Grommet, Spring, Filter, Valve And Ring) | 1 |
7c-3617 Housing Gp-Flywheel
| 0S***91 | Screw,Cap,Hexagon Bearing Retainer; Part Of Kit P/N 1w***82 | 1 |
| 16***94 | Gasket | 1 |
| 1C***51 | Bolt--Installation Of 2v***26 Retainer | 2 |
126-7280 Housing Gp-Front
| 0L***52 | Capscrew (3/8 - 16 Nc X 3 1/4 Gd8, Hex) | 2 |
| 0T***73 | Bolt (3/8) (63.5mm Long) (On Cab Of Cover Assem.) | 3 |
| 12***80 | Housing Group-Front | 1 |
126-2267 Lifting Gp-Engine
| 0S***87 | Bolt-Bracket Assembly To Timing Gear | 4 |
| 11***75 | Bracket-Lifting; (Right) | 1 |
| 11***15 | Bracket-Lifting; (Left) | 1 |
114-5213 Lines Gp-Air Compressor
| 03***49 | Elbow; (90 Degree, 37 Degree Flared) | 1 |
| 03***69 | Elbow-Flared; (1/2-14 Nptf) | 1 |
| 0S***09 | Bolt (3/4") Filler Tube Assembly To Transfer Drive Case | 1 |
6i-3744 Pan Gp-Oil -Engine
| 11***14 | Pan-Oil; (Engine Oil) | 1 |
| 2P***03 | Bolt-Washer Head; (3/8-16x1.25-In) | 32 |
| 4N***51 | Gasket; (Engine Oil Pan) | 1 |
192-8808 Piston & Rod Gp
| 13***61 | Ring-Piston; (Top)(Top) | 1 |
| 15***56 | Bolt-Special; (Oil Jet) | 1 |
| 16***78 | Rod As-Connecting | 1 |
125-9323 Plug Gp-Cylinder Block
| 12***23 | Plug Group-Cylinder Block | 1 |
| 6V***89 | Seal-O-Ring (Id=19.18mm) | 3 |
| 7W***34 | Plug-Pipe (3/8-18 Nptf Thd) | 6 |
126-1336 Plug Gp-Cylinder Head
| 12***36 | Plug Group-Cylinder Head | 1 |
| 4N***32 | Plug-Cup | 2 |
| 5P***63 | Plug-Cup | 3 |
107-1954 Rocker Arm Gp
| 10***54 | Rocker Arm Group | 1 |
| 10***03 | Screw; (3/8-24x1.67-In)(Intake) | 2 |
| 12***63 | Bracket-Shaft | 1 |
319-0785 Seal Gp-Crankshaft -Rear
| 14***68 | Seal-Crankshaft; (Rear)(Flywheel Housing) | 1 |
| 31***85 | Seal Group-Crankshaft; -Rear | 1 |
319-7401 Seal Gp-Crankshaft -Front
| 14***67 | Seal Group-Crankshaft; (Front) | 1 |
| 31***01 | Seal Group-Crankshaft; -Front | 1 |
108-2796 Support Gp-Engine
| 10***96 | Support Group-Engine | 1 |
| 22***72 | Support-Engine | 1 |
| 2H***88 | Bolt- 12 cm(4.75 In.) Long-Location "F" | 2 |
108-1551 Valve Mechanism Gp
| 0L***43 | Bolt 63.5 mm (3/8" X 2 1/2" -Cover Assembly To Fender | 8 |
| 10***89 | Bridge-Valve | 16 |
| 10***88 | Valve Lifter Assem | 16 |
Cooling System
134-5954 Lines Gp-Water
| 0L***43 | Bolt 63.5 mm (3/8" X 2 1/2" -Cover Assembly To Fender | 1 |
| 0S***87 | Bolt-Bracket Assembly To Timing Gear | 5 |
| 0S***88 | Bolt,Machine; Hose Assembly Mounting,Hose Assembly To Transmission,And To Torque Converter | 6 |
126-1337 Lines Gp-Water
| 0L***52 | Capscrew (3/8 - 16 Nc X 3 1/4 Gd8, Hex) | 1 |
| 0S***71 | Screw,Cap,Hexagon; Tube Assembly To Turbocharger And Elbow Mounting | 4 |
| 0S***88 | Bolt,Machine; Hose Assembly Mounting,Hose Assembly To Transmission,And To Torque Converter | 1 |
126-4944 Lines Gp-Water
| 0S***88 | Bolt,Machine; Hose Assembly Mounting,Hose Assembly To Transmission,And To Torque Converter | 1 |
| 0S***94 | Bolt (1 In. Long 3/8 In. Dia.); Plate Assembly To Support Assembly | 8 |
| 0S***21 | Bolt --Brace To Starting Engine Mounting Pad; Bolt-- Brace To Starting Engine Mounting Pad | 1 |
137-1338 Pump Gp-Water
| 0S***91 | Screw,Cap,Hexagon Bearing Retainer; Part Of Kit P/N 1w***82 | 1 |
| 10***30 | Bearing As-Roller | 1 |
| 11***21 | Plug-Felt; (Water Pump Housing) | 1 |
4n-1951 Pump Gp-Water
| 10***49 | Adapter-Inlet | 1 |
| 11***79 | Seal-O-Ring | 1 |
| 11***80 | Seal-O-Ring | 1 |
Electrical And Starting System
3e-7577 Alternator Gp-Charging
| 10***31 | Fan-Alternator; (11-Blade) | 1 |
| 10***32 | Collar; (Alternator) | 1 |
| 10***56 | Diode As; (Alternator) | 1 |
7c-1989 Alternator Gp-Charging
| 13***77 | V-Belt; (Alternator) | 1 |
| 1S***89 | Rod End,Generator C Bracket Uoc:Bsu,Bsw | 1 |
| 2W***15 | Wire As; (Alternator) | 1 |
109-0400 Control & Mtg Gp-Engine Elek
| 10***00 | Control & Mtg Group-Engine Elek | 1 |
| 11***69 | Spacer-Special; (8.2x25x89.7-mm Thk) | 4 |
| 15***72 | Control Group-Engine Electronic | 1 |
156-7172 Control Gp-Engine Electronic
| 12***74 | Screw-Pan Head; (8-32x9.52-mm) | 1 |
| 13***26 | Washer; (4.52x8.28x0.76-mm Thk) | 1 |
| 15***72 | Control Group-Engine Electronic | 1 |
322-7931 Conversion Gp-Alternator & Dec
| 12***44 | Control Group-Governor | 1 |
| 32***31 | Conversion Group-Alternator & Dec | 1 |
| 8C***54 | Cap-Receptacle | 1 |
204-7949 Sensor Gp-Position
| 10***03 | Kit; (Receptacle) (3-Pin) (Includes Receptacle As & Wedge) | 1 |
| 18***35 | Pin-Connector; (16-Ga To 18-Ga) | 3 |
| 20***49 | Sensor Group-Position; -Throttle | 1 |
194-6724 Sensor Gp-Pressure
| 15***60 | Kit-Connecting Plug; (3-Pin)(Engine Sensor Wiring Harness) | 1 |
| 19***26 | Harness As-Sensor; (16-18 Ga Wire)(Engine Oil Temperature) | 3 |
| 19***24 | Sensor Group-Pressure; -Air Inlet Manifold | 1 |
161-9931 Sensor Gp-Pressure
| 15***60 | Kit-Connecting Plug; (3-Pin)(Engine Sensor Wiring Harness) | 1 |
| 16***31 | Sensor Group-Pressure; -Atmospheric | 1 |
| 18***36 | Socket-Connector; (16-Ga To 18-Ga) | 3 |
194-6725 Sensor Gp-Pressure
| 15***60 | Kit-Connecting Plug; (3-Pin)(Engine Sensor Wiring Harness) | 1 |
| 18***40 | Socket-Connector; (14-Ga To 18-Ga)(14-Ga To 18-Ga) | 3 |
| 19***25 | Sensor Group-Pressure; -Engine Oil | 1 |
167-1709 Sensor Gp-Pressure
| 15***60 | Kit-Connecting Plug; (3-Pin)(Engine Sensor Wiring Harness) | 1 |
| 16***09 | Sensor Group-Pressure; -Injection Actuation Oil | 1 |
| 9X***13 | Sleeve (Order By cm)(Use As Required) | 0 |
194-6722 Sensor Gp-Pressure
| 15***60 | Kit-Connecting Plug; (3-Pin)(Engine Sensor Wiring Harness) | 1 |
| 18***40 | Socket-Connector; (14-Ga To 18-Ga)(14-Ga To 18-Ga) | 3 |
| 19***22 | Sensor Group-Pressure; -Atmospheric Air | 1 |
265-9033 Sensor Gp-Speed
| 15***60 | Kit-Connecting Plug; (3-Pin)(Engine Sensor Wiring Harness) | 2 |
| 19***26 | Harness As-Sensor; (16-18 Ga Wire)(Engine Oil Temperature) | 3 |
| 19***27 | Harness As-Sensor; (14-Ga Wire)(Engine Oil Temperature) | 3 |
129-6628 Sensor Gp-Speed
| 10***13 | Seal; (3 Pin Plug) | 1 |
| 12***28 | Sensor Group-Speed; -Engine Speed/Timing | 1 |
| 15***60 | Kit-Connecting Plug; (3-Pin)(Engine Sensor Wiring Harness) | 1 |
106-0735 Sensor Gp-Temperature
| 10***03 | Kit; (Receptacle) (3-Pin) (Includes Receptacle As & Wedge) | 1 |
| 10***35 | Sensor Group-Temperature; -Engine Oil | 1 |
| 18***35 | Pin-Connector; (16-Ga To 18-Ga) | 3 |
102-2240 Sensor Gp-Temperature
| 10***40 | Sensor Group-Temperature; -Output Transfer Gear Oil | 1 |
| 10***03 | Kit; (Receptacle) (3-Pin) (Includes Receptacle As & Wedge) | 1 |
| 18***35 | Pin-Connector; (16-Ga To 18-Ga) | 3 |
100-4417 Switch Gp-Flow
| 10***17 | Switch Group-Flow; -Engine Coolant | 1 |
| 17***08 | Switch Group-Flow; -Engine Coolant | 1 |
| 2B***95 | Cap Screw--Tube Assembly To Air Inlet Pipe | 2 |
121-4082 Wiring Gp-Engine Electronic
| 0S***09 | Bolt (3/4") Filler Tube Assembly To Transfer Drive Case | 1 |
| 0S***94 | Bolt (1 In. Long 3/8 In. Dia.); Plate Assembly To Support Assembly | 1 |
| 0S***20 | Bolt--Customer Grounding Bolt | 1 |
109-0401 Wiring Gp-Unit Injector
| 03***34 | Seal-O-Ring | 1 |
| 10***61 | Clip | 1 |
| 10***01 | Wiring Group-Unit Injector | 1 |
Engine Arrangement
225-0404 Conversion Ar-Engine
| 22***97 | Engine Ar | 1 |
| 22***04 | Conversion Ar-Engine | 1 |
| 32***31 | Conversion Group-Alternator & Dec | 1 |
225-0397 Engine Ar
| 10***17 | Switch Group-Flow; -Engine Coolant | 1 |
| 10***19 | Cylinder Head Group | 1 |
| 10***47 | Camshaft Group | 1 |
322-7950 Installation Gp-Engine
| 32***50 | Installation Group-Engine | 1 |
| 7C***89 | Alternator Group-Charging | 1 |
Fuel System
126-9544 Control Gp-Governor
| 12***33 | Pedal | 2 |
| 12***34 | Plate As | 2 |
| 12***14 | Pin | 2 |
180-6649 Drive Gp-Unit Inj Hyd Pump
| 03***01 | Bolt; --To Reverse Shaft Bearing Retainer | 2 |
| 0S***18 | Bolt; (5/16-18x1-In)(Hydraulic Pump) | 2 |
| 12***40 | Plate | 1 |
125-3428 Drive Gp-Unit Inj Hyd Pump
| 11***35 | Pin | 1 |
| 12***28 | Drive Group-Unit Inj Hydraulic Pump | 1 |
| 18***49 | Drive Group-Unit Inj Hydraulic Pump | 1 |
232-1168 Injector Gp-Fuel
| 11***98 | Adapter-Injection | 1 |
| 11***22 | Seal-Rectangular | 1 |
| 13***69 | Bolt-Socket Head | 2 |
166-5985 Kit-Compensator
| 16***85 | Kit-Compensator | 1 |
138-6256 Kit-Seal -Unit Injector Hydraulic Pump
| 03***53 | Seal-O-Ring; (08.92mm Id) | 3 |
| 03***27 | Seal-O-Ring; (19.18mm Id) | 2 |
| 03***39 | Seal-O-Ring (Id=9.25mm) | 1 |
126-4037 Lines Gp-Fuel Filter
| 03***33 | Seal-O-Ring; (12.42mm Id) | 4 |
| 0L***51 | Bolt Starting Engine Fuel Tank Bracket To Diesel Intake Manifold | 1 |
| 0S***09 | Bolt (3/4") Filler Tube Assembly To Transfer Drive Case | 1 |
121-4034 Lines Gp-Injector Hyd Pump
| 0L***43 | Bolt 63.5 mm (3/8" X 2 1/2" -Cover Assembly To Fender | 2 |
| 0S***88 | Bolt,Machine; Hose Assembly Mounting,Hose Assembly To Transmission,And To Torque Converter | 1 |
| 10***02 | Tube As | 1 |
126-7292 Pump & Mtg Gp-Unit Inj Hyd
| 03***33 | Seal-O-Ring; (12.42mm Id) | 1 |
| 0L***70 | Bolt (2-1/4") Filler Tube Assembly To Transfer Drive Case | 1 |
| 0S***17 | Bolt --Use Open Hole In Compressor Body | 4 |
206-2630 Pump Gp-Fuel Injection
| 10***26 | Clamp-Injector | 1 |
| 11***21 | Seal-Rectangular | 2 |
| 11***08 | Elbow-Injector | 1 |
235-2024 Pump Gp-Unit Injector Hyd
| 0S***17 | Bolt --Use Open Hole In Compressor Body | 4 |
| 11***20 | Coupling | 1 |
| 14***50 | Pump Group-Fuel Transfer | 1 |
235-2026 Pump Gp-Unit Injector Hyd
| 03***39 | Seal-O-Ring (Id=9.25mm) | 2 |
| 03***42 | Seal-O-Ring; (11.89mm Id) | 3 |
| 13***05 | Gasket-Housing | 1 |
282-1915 Valve Gp-Check
| 03***33 | Seal-O-Ring; (12.42mm Id) | 1 |
| 28***15 | Valve Group-Check; -Fuel | 1 |
| 6V***89 | Seal-O-Ring (Id=19.18mm) | 1 |
190-0016 Valve Gp-Fuel
| 03***53 | Seal-O-Ring; (08.92mm Id) | 3 |
| 10***77 | Valve Group-Solenoid; -Pressure Control | 1 |
| 19***16 | Valve Group-Fuel | 1 |
161-2309 Valve Gp-Fuel
| 03***43 | Seal-O-Ring | 1 |
| 10***06 | Seal-O-Ring (10.52mm Id) | 1 |
| 10***85 | Seal-O-Ring (6.07mm Id) | 2 |
165-1536 Valve Gp-Pressure Control
| 03***27 | Seal-O-Ring; (19.18mm Id) | 2 |
| 03***28 | Seal-O-Ring | 1 |
| 10***03 | Seal-O-Ring; (7.65mm Id) | 1 |
107-0677 Valve Gp-Solenoid
| 03***28 | Seal-O-Ring | 1 |
| 03***39 | Seal-O-Ring (Id=9.25mm) | 1 |
| 10***77 | Valve Group-Solenoid; -Pressure Control | 1 |
Lubrication System
119-8583 Fastener Gp-Oil Pump Mounting -Engine
| 0L***43 | Bolt 63.5 mm (3/8" X 2 1/2" -Cover Assembly To Fender | 1 |
| 0S***19 | Bolt,Machine Gear Retaining Part Of Kit P/N 1w***46 | 2 |
| 11***83 | Fastener Group-Oil Pump Mounting; -Engine | 1 |
125-8280 Filler Gp-Engine Oil
| 0S***88 | Bolt,Machine; Hose Assembly Mounting,Hose Assembly To Transmission,And To Torque Converter | 1 |
| 12***81 | Tube As | 1 |
| 12***80 | Filler Group-Engine Oil | 1 |
4n-2357 Filter Gp-Engine Oil
| 0S***71 | Screw,Cap,Hexagon; Tube Assembly To Turbocharger And Elbow Mounting | 4 |
| 1R***16 | Filter As-Engine Oil; (Standard Efficiency) | 2 |
| 2P***03 | Base As-Oil Filter; (Engine) | 2 |
125-8279 Gauge Gp-Oil Level (Dipstick) -Engine
| 06***39 | Seal-O-Ring | 1 |
| 0L***51 | Bolt Starting Engine Fuel Tank Bracket To Diesel Intake Manifold | 1 |
| 0S***94 | Bolt (1 In. Long 3/8 In. Dia.); Plate Assembly To Support Assembly | 1 |
125-8277 Lines Gp-Engine Oil
| 0L***51 | Bolt Starting Engine Fuel Tank Bracket To Diesel Intake Manifold | 1 |
| 0S***71 | Screw,Cap,Hexagon; Tube Assembly To Turbocharger And Elbow Mounting | 1 |
| 0S***88 | Bolt,Machine; Hose Assembly Mounting,Hose Assembly To Transmission,And To Torque Converter | 2 |
125-8278 Lines Gp-Filter
| 06***40 | Seal-O-Ring (Id=37.69mm) | 4 |
| 0L***70 | Bolt (2-1/4") Filler Tube Assembly To Transfer Drive Case | 1 |
| 0S***71 | Screw,Cap,Hexagon; Tube Assembly To Turbocharger And Elbow Mounting | 4 |
126-5034 Lines Gp-Turbocharger Oil
| 0L***70 | Bolt (2-1/4") Filler Tube Assembly To Transfer Drive Case | 1 |
| 0S***08 | Bolt-Support To Starting Engine Timing Gear Housing | 2 |
| 10***34 | Grommet | 1 |
116-1980 Pump Gp-Engine Oil
| 10***82 | Shaft As-Pump Drive | 1 |
| 10***73 | Shaft As-Idler | 1 |
| 11***79 | Body As-Oil Pump | 1 |
Power Train
4n-2210 Cooler Gp-Transmission Oil
| 4N***10 | Cooler Group-Transmission Oil; Oil Cooler Group--Transmission | 1 |
| 7S***67 | Gasket | 2 |
| 7W***59 | Core Group-Oil Cooler | 1 |
7w-6459 Core Gp-Oil Cooler
| 6V***49 | Seal-O-Ring (Id=11.89mm); (11.89-mm Id) | 2 |
| 7W***59 | Core Group-Oil Cooler | 1 |
| 9S***91 | Plug,Machine Thread Fuel Injection Pump | 2 |
Frequently asked questions
What engine powers the Caterpillar 637E tractor?
The tractor unit is typically powered by a Caterpillar 3408E or 3306 engine, providing net power up to 490 hp (366 kW) depending on the specific configuration and gear range.
What is the maximum operating weight of the 637E?
The machine's weight varies by configuration; when empty, the tractor and scraper together weigh approximately 113,500 lb (51,480 kg), but this can exceed 190,500 lb (86,400 kg) at maximum rated load.
What machine replaced the 637E?
The 637E was part of a lineage that includes the 637D and eventually the 637G, which serves as the flagship of the 637 family.
What 637E owners discuss
What causes the rear end to experience 'speed wobble' or bouncing during high-speed travel on a 637E twin power configuration?
The lack of a rear differential can exacerbate this issue as both tires apply equal force constantly. Operators may mitigate this by slightly reducing rear throttle, though using separate throttles for each engine is recommended to maintain control. Check nitrogen-over-oil accumulator pressures in the cushion hitch; correct pressure is critical for dampening road shocks.
What are the primary engine configurations and fuel system characteristics for the 637E Series II?
The 637E II scraper utilizes a 3306 engine featuring an adjustment-free direct injection fuel system with individual injection pumps and valves. For the tractor unit, the 3408E engine uses an electronically controlled unit injector fuel system.
What common electrical issues should be monitored on Caterpillar heavy equipment like the 637E?
Electrical instability is a frequent issue. Common root causes include moisture intrusion into connectors, loose or corroded grounds, and battery deterioration. Because modern systems depend on stable voltage, a weak battery can cause the ECM to behave erratically, often leading operators to incorrectly assume a control unit failure.
What hydraulic maintenance is required to prevent pump destruction in Caterpillar machines?
Avoid cross-contamination when topping off fluids; Caterpillar requires less than 10% cross-contamination when switching oils. Use Cat HYDO Advanced oils to protect components and ensure maximum efficiency. Low hydraulic oil levels can cause cavitation, which destroys pumps.
What are the known engine-related failure symptoms for Caterpillar power units?
Power loss, smoke, or overheating are primary indicators of trouble. These are often linked to airflow issues like dust accumulation choking filters (which can damage turbochargers), fuel contamination destroying injectors, or cooling system blockages. Clean fuel and air are essential for engine longevity.
What should be inspected when purchasing a used 637E scraper?
Inspect the cushion hitch gooseneck for functionality and check the nitrogen-over-oil accumulator pressures. Verify the condition of the piston-actuated bowl, apron, and ejector components. Check for any signs of electrical connector moisture or wiring harness stress.
Compiled from owner and technician discussions across the industry — experiences vary by serial range and machine history.
Serial-range & configuration variants
This page covers the Caterpillar 637E. Related factory variants of the same model family:
637E
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