Caterpillarwheel tractor-scraperwheel tractor
Caterpillar 651E
Maintenance schedule, common problems & OEM parts breakdown
The Caterpillar 651E is a heavy-duty wheel tractor-scraper designed for large-scale earthmoving and mass excavation. This machine belongs to the partial scraper class, often utilized as a power unit for specialty attachments like water pulls or elevating scrapers. The series features a single-engine configuration, with specific models in this lineage utilizing the Cat 3412E diesel engine capable of producing 5ered 550 HP at 1,900 RPM. The machine is characterized by its significant dimensions, featuring an operating length of approximately 52.96 ft (16.14 m) and a width of roughly 12-13 ft depending on configuration.
Across generations, the 651E represents a bridge between legacy scraper technology and modern high-efficiency earthmoving. While newer iterations like the 651 focus on reducing CO2 emissions by up to 15%, the 651E remains a staple in the used equipment market due to its robust 3412E powertrain and proven structural design. Its value in the secondary market is driven by its versatility as a tractor-only unit, allowing fleet managers to integrate it into various specialized applications beyond traditional soil stripping.
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 651E specifications
Engine
| Model | 3412E |
| Gross Power | 550 hp (410 kW) |
| Net Power (Gears 1-2) | 550 hp |
| Gross Power (Gears 3-8) | 632 hp |
| Net Power (Gears 3-8) | 605 hp |
| Displacement | 1649 cu in |
| Bore | 5.4 in |
| Stroke | 6 in |
Weights
| Operating Weight (Empty) | 61,121.5 kg (134,760 lb) |
| Operating Weight (Loaded) | 108,296.5 kg (238,760 lb) |
| Total Shipping Weight | 59,994.5 kg (132,717 lb) |
| Tractor Shipping Weight | 30,721.5 kg (67,726 lb) |
| Scraper Shipping Weight | 29,479.5 kg (64,991 lb) |
| Front Axle Weight (Empty) | 40,123.5 kg (88,460 lb) |
| Rear Axle Weight (Empty) | 21,001.5 kg (46,300 lb) |
| Front Axle Weight (Loaded) | 57,396.5 kg (126,543 lb) |
| Rear Axle Weight (Loaded) | 50,901.5 kg (112,217 lb) |
Dimensions
| Overall Length | 16.14 m (52.96 ft) |
| Overall Width | 4.35 m (14.28 ft) |
| Overall Height | 4.71 m (15.46 ft) |
| Wheelbase | 32.55 ft - 32.72 ft (9.92 m - 9.97 m) |
| Shipping Height | 185.4 in (4.71 m) |
| Width - Inside Bowl | 154 in (3.91 m) |
| Ground Clearance (Maximum) | 22.8 in (0.58 m) |
Performance
| Max Speed Forward | 50.06 km/h (31.1 mph) |
| Reverse Speed | 9.17 km/h (5.7 mph) |
| Forward Gear Speeds | 5.15, 9.33, 11.26, 15.13, 20.44, 27.69, 37.02, 50.06 km/h (3.2, 5.8, 7, 9.4, 12.7, 17.2, 23, 31.1 mph) |
| Rated Payload | 47,200 kg (104,058.2 lb) |
| Heaped Capacity | 33.64 m³ (44 yd³) |
| Struck Capacity | 24.54 m³ (32.1 yd³) |
| Max Depth of Cut | 26 in (0.66 m) |
Service capacities (summary)
| Fuel Capacity | 260.3 gal (985.4 L) |
| Hydraulic Reservoir | 79 gal (299 L) |
| Transmission Capacity | 36 gal (136.3 L) |
| Differential Capacity | 35 gal (132.5 L) |
| Cooling System Capacity | 37 gal (140 L) |
| Crankcase Capacity | 18 gal (68.1 L) |
Values vary by configuration, region, and serial range — confirm against your machine before planning transport or lifts.
651E fluids & capacities
| System | Capacity | Recommended fluid |
|---|---|---|
| Engine crankcase (with filter) | Not documented for this exact serial range — verify with your dealer | CAT DEO or DEO-ULS; SAE 15W-40, SAE 10W-30, or SAE 0W-40 (cold weather) depending on configuration/series |
| Cooling system | Not documented for this exact serial range — verify with your dealer | Caterpillar ELC |
| Fuel tank | Not documented for this exact serial range — verify with your dealer | Not specified |
| Hydraulic system and tank | Not documented for this exact serial range — verify with your dealer | Cat HYDO Advanced; use bio-based hydraulic fluid to optimize drain intervals |
| Grease | Not documented for this exact serial range — verify with your dealer | CAT Multipurpose Grease (low-load/low-speed), CAT Advanced 3Moly Grease (medium-load/medium-speed), or CAT Ultra 5Moly Grease (high-load/high-speed) |
Capacities are refill values from factory literature — always fill to the dipstick/sight gauge, not the number.
Caterpillar 651E maintenance schedule
| Service interval | Tasks |
|---|---|
| Every 10 h |
|
| Every 250 h |
|
| Every 500 h |
|
| Every 1,000 h |
|
| Every 2,000 h |
|
Servicing the 651E beyond the schedule
Predictive Maintenance & Fluid Analysis
Utilize Cat S.O.S Services to monitor engine oil, hydraulic fluid, and coolant. Analyze for wear metals like iron or copper, and contaminants such as silicon (dirt) or sodium (coolant). For the 651E, tracking particle counts in hydraulic oil is critical to prevent pump failure. Use Cat HYDO Advanced oils to maintain system cleanliness and extend drain intervals, ensuring additive packages remain compatible to avoid sludge formation.
Corrective & Common Repairs
Monitor for common failures such as hydraulic pump cavitation caused by low fluid levels or air ingestion. Inspect hydraulic hoses regularly for cracks, abrasion, or leaks that lead to pressure loss. Address fuel/water separator contamination immediately to prevent injector damage. If engine oil appears milky, investigate potential head gasket failure or coolant leaks into the lubrication system. Ensure all pins and bushings are lubricated to prevent costly articulation joint repairs.
Overhaul & Rebuild Points
Plan for major component evaluations during 2,000-hour intervals. Key rebuild focus areas include the transmission system, final drives, and the turbocharger. Inspect structural welds on the chassis and scraper frame for fatigue. When performing engine overhauls, verify the condition of pistons, rings, and bearings. For the 651E, evaluating the integrity of the cushion hitch and hydraulic cylinders is essential to maintaining effective earthmoving performance.
Seasonal & Environment Servicing
In high-dust or quarry environments, shorten air filter inspection intervals and clean radiator/oil cooler fins daily. For machines operating in hot climates, prioritize checking coolant SCA levels to prevent liner pitting. In cold weather operations, utilize Cat DEO-ULS Cold Weather engine oil to ensure proper lubrication. Always inspect tire inflation and condition before seasonal transitions to maintain traction and stability during heavy loading cycles.
651E common service parts
| Part number | Part | Notes | |
|---|---|---|---|
| 129-0372 | Filter As-Water Sep & Fuel | Fuel system service | Check fitment → |
| 129-0375 | Bowl As-Water Collection | Fuel system service | Check fitment → |
| 1R-1808 | 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.
651E fault codes & troubleshooting
| Code | Meaning | Likely cause | What to do |
|---|---|---|---|
| 110-0 | Engine Coolant Temperature — Above Normal | Low coolant level, thermostat failure | Inspect cooling system, refill coolant, test thermostat |
| 110-3 | Engine Coolant Temp Sensor — Voltage High | Open circuit or sensor failure | Check wiring; 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; test speed sensor and tone ring |
| 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 |
| E360 | Engine Coolant Temperature — High | Low coolant, 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 |
Codes and remedies are general guidance for this model family — always confirm with diagnostic tooling and your dealer before major repairs.
651E attachments & work tools
Scraper Bowl Configurations
Standard bowl features a 3.9 m (12.7 ft) width of cut and a maximum depth of cut of 6.6 m (260 in). Heaped capacity is rated at 44 yd³ with a struck capacity of 32.1 yd³.
Tractor-Only Power Units
Available as partial wheel tractor-scraper configurations for specialty applications. These units can be leveraged for water pulls, elevating scrapers, and lowboy trailer power units.
Mounting and Hitch Systems
Equipped with an articulating cushion hitch. The system includes a dedicated cushion hitch circuit with a 10 gal/min flow rate.
Hydraulic Arrangements
Requires specific hydraulic circuits for operation, including a scraper circuit (153 gal/min) and steering circuit (115 gal/min). Secondary ground-driven steering is available with 61.2 gal/min output.
Factory Protection and Features
Standard equipment may vary by region. Notable features include a differential lock and full hydraulic power steering.
All 651E assemblies by section
Every catalogued assembly group for the Caterpillar 651E. Open an assembly to preview the parts inside — full OEM part numbers are available in Heavy Parts AI.
Air Inlet And Exhaust System
131-3272 Aftercooler Gp-Water
| 0S***71 | Screw,Cap,Hexagon; Tube Assembly To Turbocharger And Elbow Mounting | 16 |
| 0S***90 | Bolt; (3/8-16x2in)(Clip Thru Spacer To Bracket As) | 4 |
| 0S***17 | Bolt --Use Open Hole In Compressor Body | 1 |
322-7932 Conversion Gp-Air Inlet & Exh
| 13***33 | Muffler Group | 1 |
| 32***32 | Conversion Group-Air Inlet & Exh | 1 |
131-3269 Lines Gp-Air
| 06***46 | Spacer; (.546x.840x1.72 In Thk) | 3 |
| 0L***65 | Stud; (3/8-16x1.75-In) | 1 |
| 0L***52 | Capscrew (3/8 - 16 Nc X 3 1/4 Gd8, Hex) | 3 |
179-7024 Manifold Gp-Exhaust
| 10***01 | Seal As-Exhaust | 8 |
| 10***12 | Spacer; (11.13x19.05x53-mm Thk) | 24 |
| 11***50 | Manifold-Exhaust; (Rear, Lh) | 1 |
130-5633 Muffler Gp
| 13***33 | Muffler Group | 1 |
| 16***06 | Spacer; (12.52x17.14x17.5-mm Thk) | 2 |
| 16***28 | Bracket As | 2 |
130-9199 Shield Gp-Manifold
| 10***34 | Grommet | 1 |
| 11***40 | Plate | 2 |
| 11***17 | Shield As | 2 |
127-9813 Turbocharger Gp
| 12***13 | Turbocharger Group | 1 |
| 16***10 | Turbocharger Group | 1 |
| 1S***95 | Gasket-Turbocharger To Manifold; Gasket Turbocharger To Manifold | 1 |
164-4610 Turbocharger Gp
| 0S***14 | Bolt (.25" Diameter-.50" Long) | 4 |
| 12***65 | Housing; (Turbine) | 1 |
| 12***67 | Cover-Compressor | 1 |
Basic Engine
8n-0955 Air Compressor Gp
| 0L***51 | Bolt Starting Engine Fuel Tank Bracket To Diesel Intake Manifold | 5 |
| 0S***85 | Bolt; 12.7 mm (1/2") Diameter X 38.1 mm (1 1/2") Length Generator To Engine | 3 |
| 2S***23 | Cover As; (Governor) | 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 |
185-7909 Camshaft Gp
| 0S***09 | Bolt (3/4") Filler Tube Assembly To Transfer Drive Case | 2 |
| 10***74 | Gear-Camshaft Drive; (86-Teeth) | 1 |
| 18***09 | Camshaft Group | 1 |
129-5229 Cover Gp-Cylinder Block
| 0S***94 | Bolt (1 In. Long 3/8 In. Dia.); Plate Assembly To Support Assembly | 11 |
| 12***29 | Cover Group-Cylinder Block | 1 |
| 1A***29 | Bolt (1-1/8") Tube Assembly To Transfer Drive Case | 2 |
8n-2034 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 | 2 |
| 0S***19 | Bolt,Machine Gear Retaining Part Of Kit P/N 1w***46 | 2 |
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 |
131-3263 Cover Gp-Oil Pan -Engine
| 0S***87 | Bolt-Bracket Assembly To Timing Gear | 2 |
| 0S***88 | Bolt,Machine; Hose Assembly Mounting,Hose Assembly To Transmission,And To Torque Converter | 6 |
| 10***72 | Seal-O-Ring; (40.64-mm Id) | 2 |
131-3260 Cover Gp-Valve Mechanism
| 10***88 | Base-Valve Mechanism Cover | 6 |
| 11***84 | Cover-Valve Mechanism | 2 |
| 11***15 | Cover As-Valve | 4 |
213-3202 Crankshaft As
| 15***40 | Gear-Crankshaft; (99-Teeth) | 1 |
| 21***02 | Crankshaft As | 1 |
| 4N***84 | Dowel; (.75 Long) | 1 |
4n-0922 Crankshaft Gp
| 14***67 | Seal Group-Crankshaft; (Front) | 1 |
| 14***68 | Seal-Crankshaft; (Rear)(Flywheel Housing) | 1 |
| 15***40 | Gear-Crankshaft; (99-Teeth) | 1 |
117-9512 Cylinder Block As
| 11***20 | Seal-O-Ring; (Mid-Liner) | 12 |
| 11***12 | Cylinder Block As | 1 |
| 14***17 | Seal-O-Ring; (140.20mm Id) | 12 |
126-1372 Cylinder Block As
| 12***72 | Cylinder Block As | 1 |
| 2W***15 | Insert-Liner Seat; (1.605-mm Thk)(1.59mm Thk) | 0 |
| 3P***23 | Bolt-Bearing Cap; (7/8-14x7.75-In) | 14 |
109-9010 Cylinder Block Gp
| 10***23 | Insert-Liner Seat; (5.21-mm Thk)(5.21mm Thk) | 0 |
| 10***24 | . Cover, Insert-Liner Seat; (5.16-mm Thk)(0.5-mm Us) | 0 |
| 10***25 | Insert-Liner Seat; (5.26-mm Thk)(0.5-mm Os), . Cover | 0 |
126-1373 Cylinder Block Gp
| 11***27 | Seal-O-Ring; (19.18mm Id) | 8 |
| 12***72 | Cylinder Block As | 1 |
| 12***73 | Cylinder Block Group | 1 |
143-0047 Cylinder Head As
| 14***46 | Cylinder Head As | 1 |
| 14***47 | Cylinder Head As | 1 |
| 17***88 | Guide-Valve; (Standard) | 24 |
143-0046 Cylinder Head As
| 14***46 | Cylinder Head As | 1 |
| 1W***83 | Insert-Valve Seat; (Exhaust)(Standard) | 12 |
| 3B***23 | Core Plug--Flywheel Housing Pinion Shaft Hole | 12 |
192-1322 Cylinder Head As
| 10***94 | Dowel | 2 |
| 14***46 | Cylinder Head As | 1 |
| 17***88 | Guide-Valve; (Standard) | 24 |
108-1552 Cylinder Head Gp
| 03***27 | Seal-O-Ring; (19.18mm Id) | 2 |
| 06***61 | Seal-O-Ring (Id=40.87mm) | 12 |
| 10***92 | Stud-Taperlock; (3/8-16x3.93in) | 24 |
108-1887 Cylinder Head Gp
| 10***87 | Cylinder Head Group | 1 |
| 12***21 | Valve-Exhaust | 12 |
| 12***22 | Valve-Inlet | 12 |
6n-2229 Damper Gp
| 0S***85 | Bolt; 12.7 mm (1/2") Diameter X 38.1 mm (1 1/2") Length Generator To Engine | 12 |
| 16***30 | Damper As | 1 |
| 2D***74 | Bolt; (5/8-18x6.75-In) | 8 |
8n-0954 Drive Gp-Accessory
| 0S***99 | Stud (1.4325" Long) | 1 |
| 0S***94 | Bolt (1 In. Long 3/8 In. Dia.); Plate Assembly To Support Assembly | 3 |
| 1D***17 | Nut-Plate And Angle Assembly To Hydraulic And Fuel Tanks; Nut Plate And Angle Assembly To Hydraulic And Fuel Tanks | 2 |
8n-0953 Flywheel Gp
| 0S***01 | Bolt 2.75 In. (69.85 mm) Long | 12 |
| 4D***04 | Washer,Flat Cover Mtg,Accessory Drive | 12 |
| 7W***97 | Flywheel As | 1 |
126-7282 Gear Gp-Front -Timing
| 0S***71 | Screw,Cap,Hexagon; Tube Assembly To Turbocharger And Elbow Mounting | 1 |
| 10***13 | Plate-Retaining | 1 |
| 10***16 | Gear; (85-Teeth)(Oil Pump) | 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
| 2K***98 | Seal-O-Ring | 1 |
| 2S***23 | Cover As; (Governor) | 1 |
| 4N***80 | Governor Group-Air Compressor | 1 |
7w-4380 Housing Gp-Flywheel
| 0L***51 | Bolt Starting Engine Fuel Tank Bracket To Diesel Intake Manifold | 4 |
| 0S***71 | Screw,Cap,Hexagon; Tube Assembly To Turbocharger And Elbow Mounting | 4 |
| 0T***73 | Bolt (3/8) (63.5mm Long) (On Cab Of Cover Assem.) | 5 |
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 |
131-3274 Lines Gp-Air Compressor
| 03***49 | Elbow; (90 Degree, 37 Degree Flared) | 1 |
| 03***95 | Connector-Flared | 1 |
| 03***69 | Elbow-Flared; (1/2-14 Nptf) | 1 |
4n-2647 Pan Gp-Oil -Engine
| 2P***03 | Bolt-Washer Head; (3/8-16x1.25-In) | 40 |
| 4N***47 | Pan Group-Oil; -Engine | 1 |
| 6N***96 | Gasket-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 |
131-3259 Plug Gp-Cylinder Block
| 13***59 | Plug Group-Cylinder Block | 1 |
| 6V***89 | Seal-O-Ring (Id=19.18mm) | 6 |
| 7W***34 | Plug-Pipe (3/8-18 Nptf Thd) | 4 |
124-4456 Plug Gp-Cylinder Head
| 12***56 | 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 |
7e-6385 Support Gp-Engine
| 0S***66 | Bolt-Pulley To Crankshaft Adapter | 4 |
| 4D***04 | Washer,Flat Cover Mtg,Accessory Drive | 4 |
| 4N***84 | Support-Front Engine | 1 |
1w-6934 Trunnion Gp-Engine
| 0S***73 | Bolt (102mm Long); (1/2-13x4-In) | 6 |
| 1W***14 | Adapter As | 1 |
| 1W***34 | Trunnion Group-Engine | 1 |
108-1874 Valve Mechanism Gp
| 0L***43 | Bolt 63.5 mm (3/8" X 2 1/2" -Cover Assembly To Fender | 12 |
| 10***89 | Bridge-Valve | 24 |
| 10***88 | Valve Lifter Assem | 24 |
Cooling System
131-3267 Lines Gp-Aftercooler 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 |
131-3268 Lines Gp-Turbocharger Water
| 06***13 | Connector-Flared | 1 |
| 0S***94 | Bolt (1 In. Long 3/8 In. Dia.); Plate Assembly To Support Assembly | 9 |
| 0S***21 | Bolt --Brace To Starting Engine Mounting Pad; Bolt-- Brace To Starting Engine Mounting Pad | 1 |
133-9190 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 |
Electrical And Starting System
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 |
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 |
194-6724 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 |
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 |
194-6725 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 |
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 |
273-5041 Sensor Gp-Speed
| 11***66 | Seal-O-Ring | 1 |
| 13***07 | Washer; (21.1x28.1x0.9-mm Thk) | 1 |
| 15***60 | Kit-Connecting Plug; (3-Pin)(Engine Sensor Wiring Harness) | 1 |
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 |
| 10***02 | Kit-Receptacle; (2-Pin)(Engine Sensor Wiring Harness) | 0 |
| 17***08 | Switch Group-Flow; -Engine Coolant | 1 |
131-3275 Wiring Gp-Engine
| 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 | 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
213-4483 Conversion Ar-Engine
| 21***91 | Engine Ar | 1 |
| 21***83 | Conversion Ar-Engine | 1 |
| 32***31 | Conversion Group-Alternator & Dec | 1 |
212-6991 Engine Ar
| 10***17 | Switch Group-Flow; -Engine Coolant | 1 |
| 10***52 | Cylinder Head Group | 1 |
| 10***74 | Valve Mechanism Group | 1 |
322-7933 Installation Gp-Engine
| 13***60 | Filter Group-Fuel | 1 |
| 13***99 | Shield Group-Manifold | 1 |
| 14***21 | Fumes Disposal Group | 1 |
Fuel System
126-9544 Control Gp-Governor
| 12***33 | Pedal | 2 |
| 12***34 | Plate As | 2 |
| 12***14 | Pin | 2 |
180-6644 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 |
125-3431 Drive Gp-Unit Inj Hyd Pump
| 11***35 | Pin | 1 |
| 12***31 | Drive Group-Unit Inj Hydraulic Pump | 1 |
| 18***44 | Drive Group-Unit Inj Hydraulic Pump | 1 |
130-2960 Filter Gp-Fuel
| 12***91 | Base As | 1 |
| 12***72 | Filter As-Water Sep & Fuel | 1 |
| 12***75 | Bowl As-Water Collection; (Water Separator, Fuel Filter) | 1 |
198-7912 Injector Gp-Fuel
| 11***98 | Adapter-Injection | 1 |
| 11***22 | Seal-Rectangular | 1 |
| 13***69 | Bolt-Socket Head | 2 |
232-1168 Injector Gp-Fuel
| 11***98 | Adapter-Injection | 1 |
| 11***22 | Seal-Rectangular | 1 |
| 13***69 | Bolt-Socket Head | 2 |
232-1183 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 |
131-3273 Lines Gp-Fuel Filter
| 03***33 | Seal-O-Ring; (12.42mm Id) | 4 |
| 0L***70 | Bolt (2-1/4") Filler Tube Assembly To Transfer Drive Case | 1 |
| 0S***94 | Bolt (1 In. Long 3/8 In. Dia.); Plate Assembly To Support Assembly | 4 |
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 |
225-0567 Pump Gp-Unit Injector Hyd
| 10***77 | Valve Group-Solenoid; -Pressure Control | 1 |
| 13***52 | Seal-O-Ring | 1 |
| 13***09 | Fitting | 2 |
225-0568 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 |
235-2024 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 |
102-7535 Valve Gp-Check
| 03***33 | Seal-O-Ring; (12.42mm Id) | 1 |
| 10***35 | Valve Group-Check; -Fuel Return Port | 1 |
| 6V***89 | Seal-O-Ring (Id=19.18mm) | 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 |
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 |
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 |
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***08 | Filter As-Engine Oil; (Advanced Efficiency)(High Efficiency) | 2 |
| 2P***03 | Base As-Oil Filter; (Engine) | 2 |
140-7821 Fumes Disposal Gp
| 11***48 | Bracket | 1 |
| 13***57 | Tube | 1 |
| 13***13 | Tube-Disposal | 1 |
131-3264 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 |
122-1790 Lines Gp-Engine Oil
| 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 | 2 |
| 0S***71 | Screw,Cap,Hexagon; Tube Assembly To Turbocharger And Elbow Mounting | 2 |
131-3265 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 |
131-3271 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
141-4109 Core Gp-Oil Cooler
| 14***09 | Core Group-Oil Cooler; -Brake, Frame Mount-Transmission, Engine Mount-Tc, Bk, Hoist, Engine Mount | 1 |
| 8T***64 | Plug-Pipe; (1/8-27-Thd)(Cylinder Head) | 2 |
Service Equipment And Supplies
122-9798 Plate & Film Gp
| 12***98 | Plate & Film Group | 1 |
| 3N***90 | Plate Serial Number; On R.H. Rear Bank Of Cylinder Block As Viewed From Rear Of Engine | 1 |
Water System
137-1339 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-5837 Pump Gp-Water
| 10***49 | Adapter-Inlet | 1 |
| 11***79 | Seal-O-Ring | 1 |
| 11***80 | Seal-O-Ring | 1 |
Frequently asked questions
What engine powers the Caterpillar 651E?
The 651E is equipped with a Cat 3412E diesel engine, which can produce up to 550 HP at 1,900 RPM.
What is the operating weight of this machine?
Specific operating weight varies by configuration and serial range; however, related heavy scrapers in this class typically fall within a high-weight mining or heavy earthmoving range.
What model replaced the 651E?
The Caterpillar 651 replaces the 651E, offering updated powertrain, hydraulics, and structure with up to 15% less CO2 emissions.
What 651E owners discuss
What are the known powertrain and transmission characteristics for the 651E?
The machine features an eight-speed automatic power shift transmission and a differential lock. For specific variable horsepower ratings in gears 1-2, the engine can produce 418 GHp/400 FWHp (312 kW/299 kW). It also utilizes full hydraulic power steering.
What engine is typically found in the Caterpillar 651E?
The 651E series has been documented with a Cat 3412E diesel engine, which is capable of producing 550 HP at 1,900 RPM.
What hydraulic system issues should be monitored on this machine type?
Hydraulic systems are prone to pressure loss, oil overheating, and jerky movement. These symptoms often indicate internal leakage or fluid contamination. Using incorrect hydraulic oil, such as topping off Cat HYDO Advanced with generic oils, can create sludge that clogs valves and damages pumps.
What electrical issues are common in Caterpillar heavy equipment?
Electrical instability is a frequent issue, often caused by moisture intrusion into connectors, stressed wiring harnesses, or failing charging systems. Because modern units depend on stable voltage, a weak battery can cause the ECM to behave erratically, which may be mistaken for a control unit failure.
What are the primary causes of engine power loss in these machines?
Power loss is primarily linked to airflow issues or fuel contamination. Specific causes include dirty air filters choking the turbocharger, injector failure due to low-quality fuel, and cooling system blockages leading to overheating.
What should be checked when inspecting a used 651E for purchase?
Verify the exact serial-prefix specification sheet and the installed attachment package. Check for signs of oil contamination, such as milky oil which indicates coolant contamination from a potential head gasket failure. Additionally, inspect electrical connectors for moisture and check the condition of the engine's air filters.
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 651E. Related factory variants of the same model family:
651E
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