Caterpillarpaving compactorvibratory compactor
Caterpillar CP-643
Maintenance schedule, common problems & OEM parts breakdown
The Caterpillar CP-643 is a self-propelled, single-drum padfoot vibratory soil compactor built for compacting cohesive and semi-cohesive fill on grading, embankment, and utility trench work. Cat's catalog files it under the generic "paving compactor" category, but it's a soil-class machine, not an asphalt roller. It dates to the 1980s, part of Cat's early single-drum compactor lineup that grew out of the company's 1985-1989 CMI/Raygo padfoot and smooth-drum roller line. Power comes from the Caterpillar 3304 diesel, offered naturally aspirated or turbocharged, with mechanical direct injection and no electronic engine control. The CP-643 shares its chassis and drivetrain architecture with the smooth-drum CS-643 and the larger CP-653/CS-653, and operating weight for the family sits in the 17-18.5 t (37,700-40,800 lb) class based on the better-documented CP-653/CS-653 siblings. Fuel tank capacity is confirmed at 230 L (60.8 US gal).
Parts and service listings tie the CP-643 to serial prefix 7GD, shared with its smooth-drum CS-643 sibling; the larger CP-653/CS-653 pair carries a separate prefix of its own. Confirm the exact reading against the machine's data plate. No documented model carries the CP-643 name forward as a direct replacement. Cat's later single-drum soil compactors moved to different naming schemes entirely, including D- and E-series models like the CS-533E/CP-533E and today's GC-series, so the numbering break is real, not just a rebrand. That, combined with the machine's age, puts the CP-643 almost entirely in the used-equipment and parts-support market now. Independent CP-643-specific spec sheets are scarce; buyers and shops typically cross-reference the better-documented CP-653/CS-653 class figures, then verify exact numbers against the data plate. The draw for a fleet still running one is mechanical-era simplicity: no ECM, no emissions aftertreatment, and a parts base shared across four sibling models.
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 CP-643 specifications
Engine
| Engine model | Caterpillar 3304 diesel, inline-4, direct injection. This model's own parts catalog covers both naturally aspirated and turbocharged builds. |
| Displacement | 7.0 L (427 cu in) |
| Cylinders | 4, inline |
| Gross power | Not published under the CP-643 nameplate specifically. Turbocharged 3304 builds in the same compactor line (CP-653/CS-653) rate 100 kW (134 hp) gross; naturally aspirated 3304 builds in other applications run 71-86 kW (95-115 hp). Check the build plate/serial number for the actual configuration. |
| Emissions tier | Pre-tier, mechanically governed diesel. Predates nonroad diesel emissions-tier rules for this equipment class. |
Weights
| Operating weight | Not published under the CP-643 nameplate. The same 3304-engine compactor line (CP-653/CS-653) runs 17,100-18,500 kg (37,700-40,800 lb) operating weight - class range only, not a confirmed CP-643 figure. |
Dimensions
| Transport length | About 6.15 m (20.2 ft) - CP-653/CS-653 class reference, not confirmed CP-643-specific. |
| Transport width | 2.46-2.50 m (8.1-8.2 ft) - class reference. |
| Transport height (to cab/canopy top) | 3.60-3.70 m (11.8-12.1 ft) - class reference. |
| Drum width | About 2.2 m (86.6-86.7 in) - class reference. |
| Drum diameter | 1.50-1.70 m (59.1-66.9 in), depends on drum shell type (pad-shell vs smooth) - class reference. |
Performance
| Max travel speed | 15.6 km/h (9.7 mph) - CP-653/CS-653 class reference. |
| Vibration frequency | 32.5 Hz (about 1,950 vpm) - class reference. |
| Centrifugal force, high amplitude | About 218 kN (49,000 lbf) - class reference. |
Service capacities (summary)
| Fuel tank | 230 L (60.8 US gal). |
| Hydraulic system | About 130 L (34.4 US gal) - CP-653/CS-653 class reference, not separately confirmed for the CP-643. |
Values vary by configuration, region, and serial range — confirm against your machine before planning transport or lifts.
CP-643 fluids & capacities
| System | Capacity | Recommended fluid |
|---|---|---|
| Engine crankcase (with oil filter) | Not published for this exact machine in currently available documentation — verify against the data plate/OMM for the specific engine rating fitted (naturally aspirated vs turbocharged Cat 3304). | Cat Diesel Engine Oil (Cat DEO), SAE 15W-40 for general service; drop to SAE 10W-30 in cold climates. API CF/CF-4-equivalent oil is acceptable where Cat DEO is not available. |
| Cooling system | Not published for this exact machine in currently available documentation — verify against the OMM or with your dealer. | Cat commercial coolant/antifreeze with supplemental coolant additive, mixed to the climate chart in the OMM (typically 50/50 water-glycol for temperate service, higher glycol ratio in cold climates). |
| Fuel tank | 230 L (60.8 US gal) | No. 2-D diesel fuel (ASTM D975) for normal operation; switch to No. 1-D or a winterized No. 2-D blend below freezing to prevent fuel waxing/gelling. |
| Hydraulic system (tank, incl. propel and vibratory circuits) | Not published for this exact machine in currently available documentation — verify against the OMM or with your dealer. | Cat TDTO (Transmission/Drive Train Oil) or an equivalent Cat hydraulic oil, general grade SAE 10W; select viscosity by ambient temperature per the OMM's climate chart. |
| Power train — axle differential and final drives | Not published for this exact machine in currently available documentation — verify against the OMM or with your dealer. | Cat TDTO (Transmission/Drive Train Oil), viscosity selected per the OMM's climate chart for axle and final-drive service. |
| Grease (chassis and drum-bearing points) | Spec only — no fill capacity; applied at scheduled grease points per the lubrication chart. | Cat Multipurpose Grease (Cat MPGM), NLGI Grade 2, or an equivalent lithium-complex EP grease. |
Capacities are refill values from factory literature — always fill to the dipstick/sight gauge, not the number.
Caterpillar CP-643 maintenance schedule
| Service interval | Tasks |
|---|---|
| Every 10 h |
|
| Every 250 h |
|
| Every 500 h |
|
| Every 1,000 h |
|
| Every 2,000 h |
|
| Every 3,000 h |
|
Servicing the CP-643 beyond the schedule
Predictive Maintenance & Fluid Analysis
The CP-643's mechanical 3304 carries no ECM, so no fault code catches a problem early. Scheduled oil sampling carries that load instead. Pull engine oil, hydrostatic system oil, and vibratory exciter housing oil at a fixed interval and track wear-metal trends rather than single readings. Watch coolant SCA/additive concentration closely; the cooling system has no electronic monitoring. On turbocharged units, log boost pressure and exhaust smoke color at every fill. A mechanical injection pump gives no warning before a turbo seal or injector starts to fail.
Corrective & Common Repairs
Padfoot tip wear and chipped or lost pads on the drum shell are the first thing to check. Replace worn tips before they chew into the shell. Hydrostatic drum-drive and propel-drive motors are the next common failure point on a machine this age. Leaking shaft seals and worn charge pumps show up as sluggish propel or weak vibration. Mechanical injection pumps and nozzles drift out of calibration over decades of service; bench-test them rather than guessing at a fuel-related power loss. Articulation pins and bushings wear loose and need replacement.
Overhaul & Rebuild Points
At major-hour rebuild, start with the vibratory exciter and eccentric weight assembly inside the drum. Bearing and seal failure there is the single most common reason a CP-643 gets parked. The 3304's wet-sleeve block is a rebuild candidate too; sleeves, pistons, and main and rod bearings are standard wear items on the naturally aspirated or turbocharged 7.0L four. Hydrostatic pump and motor cores are usually exchanged as remanufactured units rather than rebuilt in the field. Budget for drum bearing replacement and shell re-padding as the undercarriage reaches end-of-life hours.
Seasonal & Environment Servicing
Cold-climate CP-643s need fuel and coolant SCA checked before winter; the mechanical 3304 uses an ether starting aid, not electronic pre-heat, so cold starts get harder as compression and injectors age. In hot, dusty work, service the air cleaner and radiator core more often than the base interval and watch vibratory exciter housing oil level, since heat accelerates hydrostatic and gear oil breakdown. Wash clay and soil off the drum, chassis, and articulation joint daily in wet fill work to keep grease points effective and pins clear of mud.
CP-643 fault codes & troubleshooting
| Code | Meaning | Likely cause | What to do |
|---|---|---|---|
| Engine Oil Pressure warning lamp (red, oil-can symbol) | Engine oil pressure has dropped below the safe minimum; this is a panel warning lamp, not an alphanumeric diagnostic code. | Low oil level, worn or failing oil pump, plugged oil filter, or a faulty pressure sender/switch. | Shut the engine down immediately, check oil level and look for leaks, inspect the sender before restarting. |
| Coolant Temperature gauge / high-temp warning lamp (red) | Engine coolant temperature has exceeded the normal operating range. | Low coolant, blocked or dirty radiator core, slipping or broken fan belt, or a stuck thermostat. | Reduce load and monitor; shut down if the lamp stays on, then check coolant level, belt, and radiator once the engine has cooled. |
| Alternator / Charging System warning lamp (battery symbol) | Charging system is not supplying current to the battery. | Failed alternator, loose or broken drive belt, corroded battery terminals, or a wiring fault. | Check belt tension and battery connections, then test alternator output. |
| Air Cleaner Restriction indicator (yellow) | Engine intake air filter restriction has reached the service limit. | Clogged primary or secondary air filter element from dust and debris buildup. | Service or replace the air filter element and reset the restriction indicator. |
| Hydraulic Filter Bypass indicator | The hydraulic return filter has gone into bypass because restriction is too high. | Clogged hydraulic filter element, cold thick oil, or contaminated hydraulic fluid. | Replace the hydraulic filter element and check hydraulic oil condition and viscosity grade. |
| Parking Brake warning lamp | Indicates the parking/secondary brake is applied. | Brake left engaged before attempting to propel the machine, or a faulty brake switch. | Release the parking brake before moving the machine; if the lamp stays lit with the brake released, check the brake switch. |
Codes and remedies are general guidance for this model family — always confirm with diagnostic tooling and your dealer before major repairs.
CP-643 attachments & work tools
Machine type and duty class
The CP-643 is a self-propelled single-drum vibratory soil compactor, catalogued under Caterpillar's legacy paving-compactor parts group but built for granular and semi-cohesive soil, subgrade, and trench-backfill compaction rather than asphalt-mat rolling. It shares its parts and service family with the smooth-drum CS-643 and the larger CS-653/CP-653 pair.
Drum type: padfoot vs smooth
CP models carry a padfoot (sheepsfoot) drum shell that kneads cohesive and semi-cohesive soils; the CS-643 companion model runs a smooth steel drum for granular fill and finish passes. On this machine the drum type is a fixed factory build rather than a field-interchangeable attachment; bolt-on padfoot shell-kit conversions are a known option on later-generation Cat single-drum compactors of similar class, but no source ties a shell-kit conversion to this specific model.
Vibratory (compaction) system
Compaction is delivered through the drum's internal vibratory exciter rather than any external work tool. Single-frequency, single-amplitude operation is typical for compactors of this size and era, with selectable or variable-amplitude vibratory systems appearing mainly on later Cat single-drum compactor generations.
Operator protection: ROPS, canopy, cab
Machines in this compactor class typically ship with an open ROPS canopy as base operator protection, with an enclosed ROPS/FOPS cab offered as a factory or dealer-installed option on single-drum vibratory compactors of similar size and era. No CP-643-specific documentation confirming exact cab or canopy option availability was found.
Drum scraper / cleaning bar
A scraper bar riding against the drum face is standard equipment on this class of soil compactor, shedding sticky material to keep the drum clean during cohesive-soil compaction. It is standard fitment, not a separate work tool.
Coupler and work-tool mounting
The CP-643 is a dedicated self-propelled roller, not a loader- or excavator-type carrier, so it has no quick-coupler, hitch, or auxiliary hydraulic circuit for interchangeable work tools such as buckets, forks, or augers. Any hydraulic-kit needs on this machine relate to its own propel and vibratory drive circuits, not to external attachments.
Engine and power class
The CP-643 and its CS-643/CS-653/CP-653 stablemates use the Caterpillar 3304 diesel, built in both naturally aspirated and turbocharged form. The 3304 family in this compactor application generally falls in a 75-95 kW (100-125 hp) range depending on aspiration and rating, though the exact factory net power specific to the CP-643 is not published in currently available sources; the 653 designation in the same family denotes a larger, heavier sibling, not a CP-643 option.
All CP-643 assemblies by section
Every catalogued assembly group for the Caterpillar CP-643. Open an assembly to preview the parts inside — full OEM part numbers are available in Heavy Parts AI.
Air Inlet And Exhaust System
1w5832 Air Cleaner Gp
| 1W***32 | Air Cleaner Group | 1 |
1w7919 Air Cleaner Gp
| 1W***19 | Air Cleaner Group | 1 |
1w3793 Fastener Gp-Exhaust Manifold
| 1W***93 | Fastener Group-Exhaust Manifold; Exhaust Manifold Fastener Group | 1 |
1w7743 Lines Gp-Air
| 1W***43 | Lines Group-Air; Air Lines Group | 1 |
1w7742 Lines Gp-Air
| 1W***42 | Lines Group-Air; Air Lines Group | 1 |
1w0558 Lines Gp-Turbocharger Oil
| 1W***58 | Lines Group-Turbocharger Oil; Turbocharger Oil Lines Group | 1 |
2p6571 Manifold Gp-Exhaust
| 2P***71 | Manifold Group-Exhaust; Exhaust Manifold Group | 1 |
1w3404 Mounting Gp-Muffler
| 1W***04 | Mounting Group-Muffler; Muffler Mounting Group | 1 |
4w1488 Muffler Gp
| 4W***88 | Muffler Group; Muffler Group | 1 |
7n4651 Turbocharger Gp*R
| 7N***51 | Turbocharger Group | 1 |
7n4650 Turbocharger Gp
| 7N***50 | Turbocharger Group | 1 |
Basic Engine
1w2872 Balancer Gp
| 1W***72 | Balancer Group; Balancer Group | 1 |
1n4436 Camshaft Gp-Single
| 1N***36 | Camshaft Group-Single; Single Camshaft Group | 1 |
2w0102 Cover Gp-Cylinder Block
| 2W***02 | Cover Group-Cylinder Block; Cylinder Block Cover Group | 1 |
2p6530 Cover Gp-Cylinder Head
| 2P***30 | Cover Group-Cylinder Head; Cylinder Head Cover Group | 1 |
2p6528 Cover Gp-Front Housing
| 2P***28 | Cover Group-Front Housing; Front Housing Cover Group | 1 |
2p6514 Cover Gp-Valve Mechanism
| 2P***14 | Cover Group-Valve Mechanism; Valve Mechansim Cover Group | 1 |
6n8080 Crankshaft Gp
| 6N***80 | Crankshaft Group; Crankshaft Group | 1 |
7n6552 Cylinder Block As
| 7N***52 | Cylinder Block As | 1 |
7n6553 Cylinder Block Gp
| 7N***53 | Cylinder Block Group; Cylinder Block Group | 1 |
7n8874 Cylinder Head Gp
| 7N***74 | Cylinder Head Group; Cylinder Head Group | 1 |
1w1393 Drive Gp-Fan
| 1W***93 | Drive Group-Fan; Fan Drive Group | 1 |
7n9534 Fastener Gp-Cylinder Head
| 7N***34 | Fastener Group-Cylinder Head; Cylinder Head Fastener Group | 1 |
8n0872 Fastener Gp-Front Housing
| 8N***72 | Fastener Group-Front Housing; Front Housing Fastener Group | 1 |
7n4824 Fastener Gp-Oil Pan
| 7N***24 | Fastener Group-Oil Pan; Oil Pan Fastener Group | 1 |
2p0976 Flywheel Gp
| 2P***76 | Flywheel Group; Flywheel Group | 1 |
1w5634 Gear Gp-Front Timing
| 1W***34 | Gear Group-Front Timing; Front Gear Group--Timing | 1 |
2w5741 Housing Gp-Flywheel
| 2W***41 | Housing Group-Flywheel | 1 |
8n0303 Housing Gp-Front
| 8N***03 | Housing Group-Front; Front Housing Group | 1 |
6n8336 Lifting Gp-Engine
| 6N***36 | Lifting Group; Lifting Eye Gp-Engine | 1 |
2p6175 Pan Gp-Engine Oil
| 2P***75 | Pan Group-Oil; Pan Gp-Engine Oil | 1 |
2w1177 Rod & Piston Gp
| 2W***77 | Piston & Rod Group; Connecting Rod And Piston Group | 1 |
7n8152 Pulley Gp
| 7N***52 | Pulley Group; Pulley Group | 1 |
7n1142 Pulley Gp-Crankshaft
| 7N***42 | Pulley Group-Crankshaft; Crankshaft Pulley Group | 1 |
2p6224 Seal Gp-Crankshaft
| 2P***24 | Seal Group-Crankshaft; Crankshaft Seal Group | 1 |
5e6630 Support Gp-Engine
| 5E***30 | Support Group | 1 |
8n4913 Support Gp-Engine
| 8N***13 | Support Group-Engine; Engine Support Group | 1 |
4c1764 Support Gp-Engine
| 4C***64 | Support Group-Engine | 1 |
8n0107 Trunnion Gp-Engine
| 8N***07 | Trunnion Group-Engine; Engine Trunnion Group | 1 |
7n8024 Valve-Mechanism Gp
| 7N***24 | Valve Mechanism Group; Valve Mechanism Group | 1 |
Braking System
8r0826 Brake Gp-Hyd Caliper Service
| 8R***26 | Brake Group-Hydraulic Caliper Service | 1 |
5e7570 Brake Gp-Parking
| 5E***70 | Brake Group-Parking | 1 |
5e6653 Brake Gp-Parking
| 5E***53 | Brake Group-Parking | 1 |
Cooling System
8n4457 Base Gp-Oil Filter
| 8N***57 | Base Group-Oil Filter; Base Group-Engine Oil Filter | 1 |
2w6954 Cooler Gp-Filter Base & Engine Oil
| 2W***54 | Cooler Group-Filter Base & Eng Oil | 1 |
2w6953 Cooler Gp-Filter Base & Engine Oil
| 2W***53 | Cooler Group-Filter Base & Eng Oil | 1 |
6a9622 Cooler Gp-Hydraulic Oil
| 6A***22 | Cooler Group-Hydraulic Oil | 1 |
7n4701 Fan Gp-Blower
| 7N***01 | Fan Group-Blower | 1 |
4w1340 Regulator & Housing Gp
| 4W***40 | Housing & Regulator Group; Housing And Regulator Group | 1 |
8n4112 Lines Gp-Water
| 8N***12 | Lines Group-Water; -Bypass Relief | 1 |
5e6643 Lines Gp-Water
| 5E***43 | Lines Group-Water | 1 |
2w6779 Lines Gp-Water
| 2W***79 | Lines Group-Water | 1 |
5e7566 Lines Gp-Water
| 5E***66 | Lines Group-Water | 1 |
2w8001 Pump Gp-Water*R
| 2W***01 | Pump Group-Water | 1 |
7n5909 Pump Gp-Water
| 7N***09 | Pump Group-Water; Water Pump Group | 1 |
1w4557 Radiator Gp
| 1W***57 | Radiator Group; Radiator Group | 1 |
4c1827 Radiator Gp-Part 2 Of 2
| 4C***27 | Radiator Group | 1 |
4c1827 Radiator Gp-Part 1 Of 2
| 4C***27 | Radiator Group | 1 |
Electrical System
9g9813 Alarm Gp
| 9G***13 | Alarm Group; -Action-Action, Engine Overspeed | 1 |
4c1825 Battery & Wiring Gp-Part 2 Of 4
| 4C***25 | Battery & Wiring Group | 1 |
4c1825 Battery & Wiring Gp-Part 3 Of 4
| 4C***25 | Battery & Wiring Group | 1 |
4c1825 Battery & Wiring Gp-Part 1 Of 4
| 4C***25 | Battery & Wiring Group | 1 |
4c1825 Battery & Wiring Gp-Part 4 Of 4
| 4C***25 | Battery & Wiring Group | 1 |
6w5798 Door Gp-Battery
| 6W***98 | Door Group-Battery | 1 |
3v0327 Door Gp-Battery
| 3V***27 | Door Group-Battery | 1 |
4c1826 Lighting Gp-Part 1 Of 2
| 4C***26 | Lighting Group | 1 |
4c1826 Lighting Gp-Part 2 Of 2
| 4C***26 | Lighting Group | 1 |
6w7071 Lighting Gp-Part 1 Of 2
| 6W***71 | Lighting Group-2 Lamp; Lighting Gp-Auxiliary Cab | 1 |
6w7071 Lighting Gp-Part 2 Of 2
| 6W***71 | Lighting Group-2 Lamp; Lighting Gp-Auxiliary Cab | 1 |
5e6665 Lighting Gp-Road
| 5E***65 | Lighting Group-Road | 1 |
5e6671 Sensor Gp (Back-Up)
| 5E***71 | Sensor Group | 1 |
7n0718 Switch As-Disconnect
| 7N***18 | Switch As-Disconnect; -Battery-Ground Level | 1 |
5e6664 Wiring Gp-Cab
| 5E***64 | Wiring Group-Cab | 1 |
8v1182 Wiring Gp-Cab
| 8V***82 | Wiring Group-Cab | 1 |
Engine Arrangement
4c1821 Engine Ar-Part 2 Of 2
| 1W***58 | Lines Group-Turbocharger Oil; Turbocharger Oil Lines Group | 1 |
| 1W***42 | Lines Group-Air; Air Lines Group | 1 |
| 2P***84 | Pump Group-Engine Oil; Engine Oil Pump Group | 1 |
4c1821 Engine Ar-Part 1 Of 2
| 1N***36 | Camshaft Group-Single; Single Camshaft Group | 1 |
| 1P***44 | Breather Group | 1 |
| 1W***72 | Balancer Group; Balancer Group | 1 |
Frame And Body
5e6667 Canopy Gp
| 5E***67 | Canopy Group | 1 |
5e6670 Counterweight Gp
| 5E***70 | Counterweight Group | 1 |
4c1742 Fender Gp-Rear
| 4C***42 | Fender Group-Rear | 1 |
8v1076 Firewall Gp
| 8V***76 | Firewall Group | 1 |
4c1835 Frame Gp
| 4C***35 | Frame Group | 1 |
5e6659 Frame Gp-Front
| 5E***59 | Frame Group-Front | 1 |
5e6660 Frame Gp-Front
| 5E***60 | Frame Group-Front | 1 |
5e7571 Frame Gp-Front
| 5E***71 | Frame Group-Front | 1 |
4c1822 Guard Gp-Radiator
| 4C***22 | Guard Group-Radiator | 1 |
5e6662 Hitch Gp (Osc)
| 5E***62 | Hitch Group | 1 |
4c1848 Hitch Gp-Articulated
| 4C***48 | Hitch Group-Articulated | 1 |
4c1823 Hood & Guard Gp
| 4C***23 | Hood & Guard Group | 1 |
4c1824 Ladder Gp
| 4C***24 | Ladder Group | 1 |
5e6661 Scraper Gp-Drum
| 5E***61 | Scraper Group-Drum | 1 |
5e7195 Support Gp-Axle
| 5E***95 | Support Group-Axle | 1 |
Fuel System
2w0262 Camshaft As
| 2W***62 | Camshaft As | 1 |
8v1072 Lines & Fuel Filter Gp
| 8V***72 | Filter & Lines Group-Primary Fuel | 1 |
1w9532 Filter Gp-Secondary
| 1W***32 | Filter Group-Fuel; Filter Gp-Secondary Fuel | 1 |
8n4123 Gov & Fuel Inj Pump Gp
| 8N***23 | Gov & Fuel Inj Pump Group; Governor And Fuel Injection Pump Group | 1 |
8n4124 Gov & Fuel Inj Pump Gp
| 8N***24 | Gov & Fuel Inj Pump Group | 1 |
7e7301 Gov & Fuel Inj Pump Gp
| 7E***01 | Gov & Fuel Inj Pump Group; Governor & Fuel Injection Pump Gp | 1 |
2w2410 Governor Gp-Part 2 Of 2
| 2W***10 | Governor Group | 1 |
2w2410 Governor Gp-Part 1 Of 2
| 2W***10 | Governor Group | 1 |
2w4107 Governor Gp-Part 2 Of 2
| 2W***07 | Governor Group | 1 |
2w4107 Governor Gp-Part 1 Of 2
| 2W***07 | Governor Group | 1 |
8n8170 Lines Gp-Fuel Injection
| 8N***70 | Lines Group-Fuel Injection | 1 |
7c5160 Lines Gp-Fuel Injection
| 7C***60 | Lines Group-Fuel Injection | 1 |
4p9950 Lines Gp-Fuel Injection
| 4P***50 | Lines Group-Fuel Injection | 1 |
4p9960 Lines Gp-Fuel Injection
| 4P***60 | Lines Group-Fuel Injection | 1 |
7c5170 Lines Gp-Fuel Injection
| 7C***70 | Lines Group-Fuel Injection | 1 |
8n2772 Lines Gp-Fuel Injection
| 8N***72 | Lines Group-Fuel Injection; Fuel Injection Lines Group | 1 |
2w0263 Pump Gp-Fuel Injection
| 2W***63 | Pump Group-Fuel Injection | 1 |
1w6539 Pump Gp-Fuel Injection
| 1W***39 | Pump Group-Fuel Injection | 1 |
1w3790 Pump Gp-Fuel Prime & Prim Fltr
| 1W***90 | Pump Group-Fuel Prime & Prim Filter; Fuel Priming Pump & Primary Filter Group | 1 |
1w1695 Pump Gp-Fuel Transfer*R
| 1W***95 | Pump Group-Fuel Transfer | 1 |
7n6831 Pump Gp-Fuel Transfer
| 7N***31 | Pump Group-Fuel Transfer | 1 |
2w4160 Fuel Transfer Pump & Mtg Gp
| 2W***60 | Pump Group-Fuel Transfer & Mtg; Fuel Transfer Pump And Mounting Group | 1 |
5e6631 Tank Gp-Fuel (230l)
| 5E***31 | Tank Group-Fuel | 1 |
5e6632 Tank Gp-Fuel (230l)
| 5E***32 | Tank Group-Fuel | 1 |
8n7276 Torque Control Gp
| 8N***76 | Torque Control Group | 1 |
Hydraulic System
4c1859 Cylinder & Mounting Gp
| 4C***59 | Cylinder & Mounting Group | 1 |
4v1446 Cylinder & Seal Gp
| 4V***46 | Cylinder & Seal Group | 1 |
3g5110 Cylinder Gp-Steer
| 3G***10 | Cylinder Group-Steering | 1 |
5e6644 Filter Gp-Oil
| 5E***44 | Filter Group-Oil | 1 |
5e7211 Lines Gp
| 5E***11 | Lines Group | 1 |
5e6651 Lines Gp (Steering)
| 5E***51 | Lines Group | 1 |
5e6639 Lines Gp-Vibration
| 5E***39 | Lines Group | 1 |
5e7564 Lines Gp-Vibration
| 5E***64 | Lines Group | 1 |
5e6654 Lines Gp-Brake
| 5E***54 | Lines Group-Brake | 1 |
8v9945 Lines Gp-Drain
| 8V***45 | Lines Group-Drain | 1 |
5e6634 Lines Gp-Propel
| 5E***34 | Lines Group-Propel | 1 |
5e7536 Lines Gp-Propel
| 5E***36 | Lines Group-Propel | 1 |
5e7395 Lines Gp-Propel-Part 2 Of 2
| 5E***95 | Lines Group-Propel | 1 |
5e7395 Lines Gp-Propel-Part 1 Of 2
| 5E***95 | Lines Group-Propel | 1 |
5e7569 Lines Gp (Steering)
| 5E***69 | Lines Group-Steering | 1 |
5e7404 Lines Gp-Steering
| 5E***04 | Lines Group-Steering | 1 |
5e6637 Motor Gp-Piston
| 5E***37 | Motor Group-Piston | 1 |
5e6638 Motor Gp-Piston (Slipper)
| 5E***38 | Motor Group-Piston | 1 |
5e6641 Motor Gp-Piston (Vibration)
| 5E***41 | Motor Group-Piston | 1 |
8v1110 Mounting Gp-Hydraulic Tank
| 8V***10 | Mounting Group-Hydraulic Tank | 1 |
5e7561 Pump Gp-Piston-Part 1 Of 2
| 5E***61 | Pump Group-Piston | 1 |
5e6635 Pump Gp-Piston-Part 1 Of 2
| 5E***35 | Pump Group-Piston | 1 |
5e6635 Pump Gp-Piston-Part 2 Of 2
| 5E***35 | Pump Group-Piston | 1 |
5e7561 Pump Gp-Piston-Part 2 Of 2
| 5E***61 | Pump Group-Piston | 1 |
4t3108 Tank & Filter Gp
| 4T***08 | Tank & Filter Group | 1 |
5e6642 Valve Gp-Divider
| 5E***42 | Valve Group-Divider | 1 |
Lubrication System
1p4244 Breather Gp
| 1P***44 | Breather Group | 1 |
2p6855 Filler Gp-Oil
| 2P***55 | Filler Group-Oil | 1 |
1w6399 Fumes Disposal Gp
| 1W***99 | Fumes Disposal Group; Fumes Disposal Group | 1 |
2p6491 Gauge Gp-Engine Oil Level
| 2P***91 | Gauge Group-Oil Level (Dipstick) | 1 |
2p6512 Lines Gp-Engine Oil
| 2P***12 | Lines Group-Engine Oil; Engine Oil Lines Group | 1 |
4w2448 Pump Gp-Engine Oil*R
| 4W***48 | Pump Group-Engine Oil; Pump Gp-Engine Oil Gear | 1 |
6n2642 Pump Gp-Engine Oil
| 0S***90 | Bolt; (3/8-16x2in)(Clip Thru Spacer To Bracket As) | 1 |
| 1P***46 | Washer-Hard; (10.2x35x6-mm Thk) | 1 |
| 4P***20 | Pump Group-Engine Oil; Pump Group-Engine Oil | 1 |
6i1346 Pump Gp-Engine Oil*R
| 6I***46 | Pump Group-Engine Oil | 1 |
2p1784 Pump Gp-Engine Oil
| 2P***84 | Pump Group-Engine Oil; Engine Oil Pump Group | 1 |
4p4020 Pump Gp-Engine Oil
| 4P***20 | Pump Group-Engine Oil; Pump Group-Engine Oil | 1 |
5c9434 Screen Gp
| 5C***34 | Screen Group; Test Screen Group | 1 |
Operator Station
8v1177 Adjuster Gp-Seat
| 8V***77 | Adjuster Group-Seat | 1 |
5e6666 Cab Gp
| 5E***66 | Cab Group | 1 |
4c1847 Cab Gp-Part 2 Of 2
| 4C***47 | Cab Group | 1 |
4c1847 Cab Gp-Part 1 Of 2
| 4C***47 | Cab Group | 1 |
5e6656 Control Gp-Forward & Reverse
| 5E***56 | Control Group | 1 |
5e6657 Control Gp-Forward & Reverse
| 5E***57 | Control Group | 1 |
2w0097 Drive Gp-Tachometer
| 2W***97 | Drive Group-Tachometer; Tachometer Drive Group | 1 |
5e6658 Gauge Gp
| 5E***58 | Gauge Group | 1 |
4c1834 Gauge Gp-Fuel
| 4C***34 | Gauge Group-Fuel | 1 |
5e6672 Gauge Gp-Tachograph
| 5E***72 | Gauge Group-Tachograph | 1 |
5e6668 Heater Gp-Cab
| 5E***68 | Heater Group-Cab | 1 |
4c1903 Installation Gp-Controls
| 4C***03 | Installation Group-Controls | 1 |
6c1679 Mirror Gp-Lh
| 6C***79 | Mirror Group-Lh | 1 |
8v1169 Mirror Gp-Rear View
| 8V***69 | Mirror Group-Rear View | 1 |
6c1315 Mirror Gp-Rh
| 6C***15 | Mirror Group-Rh | 1 |
8v1184 Mounting Gp-Cab
| 8V***84 | Mounting Group-Cab | 1 |
5e7699 Mounting Gp-Platform
| 5E***99 | Mounting Group-Platform | 1 |
8v1173 Panel Gp-Instrument-Part 1 Of 2
| 8V***73 | Panel Group-Instrument; Instrument Panel Group | 1 |
8v1173 Panel Gp-Instrument-Part 2 Of 2
| 8V***73 | Panel Group-Instrument; Instrument Panel Group | 1 |
8v1174 Panel Gp-Instrument
| 8V***74 | Panel Group-Instrument | 1 |
6v6561 Wiper Pivot Gp-Sensor
| 6V***61 | Pivot Group-Wiper Arm; (Wiper Arm) | 1 |
4c1745 Platform Gp
| 4C***45 | Platform Group | 1 |
6c1239 Rops Gp-Part 1 Of 2
| 6C***39 | Rops Group | 1 |
6c1239 Rops Gp-Part 2 Of 2
| 6C***39 | Rops Group | 1 |
5e6663 Seat Gp
| 5E***63 | Seat Group | 1 |
8v1176 Seat Gp
| 8V***76 | Seat Group | 1 |
8v1175 Seat Gp-Adjustable
| 8V***75 | Seat Group-Adjustable | 1 |
8v1181 Support Gp-Seat
| 8V***81 | Support Group-Seat | 1 |
7n8001 Switch As
| 7N***01 | Switch As-Toggle; -Prelubrication Override-Crank Override | 1 |
9g7641 Switch Gp-Start
| 9G***41 | Switch Group-Start; -Engine, Key-Vims Service | 1 |
5e6655 Throttle Gp
| 5E***55 | Throttle Group | 1 |
9v9849 Visor Gp-Cab
| 9V***49 | Visor Group-Cab | 1 |
9c1517 Washer Gp
| 9C***17 | Washer Group | 1 |
9c1518 Washer Gp
| 9C***18 | Washer Group | 1 |
9c1519 Washer Gp
| 9C***17 | Washer Group | 1 |
| 9C***18 | Washer Group | 1 |
| 9C***19 | Washer Group | 1 |
9c1520 Washer Gp
| 9C***20 | Washer Group-Windshield | 1 |
9c1522 Washer Gp
| 9C***20 | Washer Group-Windshield | 1 |
| 9C***21 | Washer Group-Windshield; Washer Gp-Nippondenso | 1 |
| 9C***22 | Washer Group-Windshield | 1 |
9c1521 Washer Gp
| 9C***21 | Washer Group-Windshield; Washer Gp-Nippondenso | 1 |
6w7333 Washer & Wiper Gp-Rear
| 6W***33 | Wiper & Washer Group | 1 |
6w7332 Washer & Wiper Gp
| 6W***32 | Wiper & Washer Group | 1 |
7x1982 Wiper Gp
| 7X***82 | Wiper Group; Wiper Group (Robert Bosch) | 1 |
7x1983 Wiper Gp
| 7X***83 | Wiper Group; Wiper Group (Nippondenso) | 1 |
3t7064 Wiper Gp-Sensor
| 3T***64 | Wiper Group-Sensor | 1 |
| 7X***82 | Wiper Group; Wiper Group (Robert Bosch) | 1 |
| 7X***83 | Wiper Group; Wiper Group (Nippondenso) | 1 |
Power Train
4c1739 Axle Gp
| 4C***39 | Axle Group | 1 |
5e6633 Coupling Gp-Pump
| 5E***33 | Coupling Group-Pump | 1 |
4c1678 Differential Gp
| 4C***78 | Differential Group | 1 |
6s6342 Differential Gp
| 6S***42 | Differential Group; Differential Group-No Spin-------------- | 1 |
4c1920 Differential Gp
| 4C***20 | Differential Group | 1 |
5e6647 Drum Gp-Front
| 5E***47 | Drum Group-Front | 1 |
5e6646 Reducer Gp-Speed
| 5E***46 | Reducer Group | 1 |
5e6929 Reducer Gp-Speed
| 5E***29 | Reducer Group | 1 |
5e7567 Reducer Gp-Speed
| 5E***67 | Reducer Group | 1 |
4c1740 Wheel & Final Drive Gp
| 4C***40 | Wheel & Final Drive Group | 1 |
4v7927 Wheel & Final Drive Gp
| 4V***27 | Wheel & Final Drive Group; Final Drive And Brake Wheel Group | 1 |
5e7212 Wheel Gp (2 Required)
| 5E***12 | Wheel Group | 1 |
8v6939 Wheel Gp-Final Drive & Brake
| 8V***39 | Wheel Group-Final Drive & Brake | 1 |
Service Equipment And Supplies
5e6673 Decal Gp
| 5E***73 | Decal Group | 1 |
5e6674 Tool Gp
| 5E***74 | Tool Group | 1 |
Starting System
1w3851 Starting Motor Gp-Electric
| 1W***51 | Starting Motor Group-Electric | 1 |
4n3181 Starting Motor Gp-Electric*R
| 3T***05 | Starting Motor Group-Electric; Starting Motor Group (Robert Bosch) | 1 |
| 4N***81 | Starting Motor Group-Electric | 1 |
| 8C***51 | Starting Motor Group-Electric; Starting Motor Gp-Electric-Delco-Remy | 1 |
9x4453 Starting Motor Gp-Electric-24 Volt
| 9X***53 | Starting Motor Group-Electric | 1 |
3t4586 Starting Motor Gp-Electric
| 3T***86 | Starting Motor Group-Electric | 1 |
| 8C***50 | Starting Motor Group-Electric | 1 |
| 8N***45 | Starting Motor Group-Electric; Electric Starting Motor Group--24 Volt | 1 |
8c3651 Starting Motor Gp-Electric
| 8C***51 | Starting Motor Group-Electric; Starting Motor Gp-Electric-Delco-Remy | 1 |
8n2145 Starting Motor Gp-Electric
| 8N***45 | Starting Motor Group-Electric; Electric Starting Motor Group--24 Volt | 1 |
9x4447 Starting Motor Gp-Electric-24 Volt
| 9X***47 | Starting Motor Group-Electric; Electric Starting Motor Group (Nippondenso) | 1 |
8c3650 Starting Motor Gp-Electric
| 8C***50 | Starting Motor Group-Electric | 1 |
3t6305 Starting Motor Gp-Electric
| 3T***05 | Starting Motor Group-Electric; Starting Motor Group (Robert Bosch) | 1 |
4w1489 Alternator Gp-Charging
| 4W***89 | Alternator Group-Charging | 1 |
5s9088 Alternator Gp-Charging*R
| 3E***78 | Alternator Group-Charging; Charging Alternator Group (Delco Remy) | 1 |
| 3T***88 | Alternator Group-Charging; Alternator Group Delco-Remy 24 Volt, 50 Ampere | 1 |
| 5S***88 | Alternator Group-Charging | 1 |
9g9538 Alternator Gp-Charging
| 9G***38 | Alternator Group-Charging | 1 |
3e7578 Alternator Gp-Charging*R
| 3E***78 | Alternator Group-Charging; Charging Alternator Group (Delco Remy) | 1 |
1005046 Alternator Gp-Charging-24 Volt, 50 Ampere
| 10***46 | Alternator Group-Charging; -24-Volt, 50-Ampere | 1 |
3t1888 Alternator Gp-Charging
| 3T***88 | Alternator Group-Charging; Alternator Group Delco-Remy 24 Volt, 50 Ampere | 1 |
6t7223 Alternator Gp-Charging
| 6T***23 | Alternator Group-Charging; Alternator Group-Nippondenso -- 24 Volt, 50 Ampere | 1 |
1005045 Alternator Gp-Charging-24 Volt, 50 Ampere
| 10***45 | Alternator Group-Charging; (Nippondenso) | 1 |
1005047 Alternator Gp-Charging-24 Volt, 50 Ampere*R
| 10***45 | Alternator Group-Charging; (Nippondenso) | 1 |
| 10***46 | Alternator Group-Charging; -24-Volt, 50-Ampere | 1 |
| 10***47 | Alternator Group-Charging; -24-Volt, 50-Ampere | 1 |
Steering System
4c1828 Column Gp-Steering-Adjustable
| 4C***28 | Column Group-Steering-Adjustable | 1 |
4c1744 Control Gp-Steering
| 4C***44 | Control Group-Steering | 1 |
5e6652 Valve Gp-Steering
| 5E***52 | Valve Group | 1 |
Vibratory System
5e7565 Pump Gp-Piston (Vibration)
| 5E***65 | Pump Group-Piston | 1 |
5e6640 Pump Gp-Piston (Vibration)
| 5E***40 | Pump Group-Piston | 1 |
5e6650 Vibrator Gp
| 5E***50 | Vibrator Group | 1 |
5e6649 Vibrator Gp
| 5E***49 | Vibrator Group | 1 |
5e6648 Vibrator Gp
| 5E***48 | Vibrator Group | 1 |
CP-643 serial number reference
The PIN/serial plate is a riveted metal tag on the machine frame near the operator's station or front frame rail, separate from any engine-block serial tag. Read the 3-character alpha-numeric prefix at the start of the stamped number, then the digit sequence number that follows; the prefix ties the unit to its build series and parts-catalog break, the sequence number pins the individual unit within that run.
| Prefix | Identifies | Notes |
|---|---|---|
| 7GD | CP-643 vibratory compactor (padfoot configuration), base production run, serials 7GD00001-UP | Fitted with the Cat 3304 diesel engine. The 7GD prefix is shared with the CS-643 smooth-drum sibling under the same parts-catalog grouping (padfoot vs smooth-drum variant of the same base machine). The larger CP-653/CS-653 pair is a separate model in the family and carries its own distinct prefix, not 7GD -- do not merge those into this range. Production era points to mid-to-late 1980s; confirm exact model year with your dealer. |
Frequently asked questions
What engine does the Caterpillar CP-643 use?
A Caterpillar 3304 diesel, offered in naturally aspirated and turbocharged versions. It's a mechanically governed, direct-injection four-cylinder with no electronic engine control, consistent with Cat's compactor line from this era.
What is the operating weight of the Caterpillar CP-643?
Cat never published a widely available CP-643-specific spec sheet. Its documented sibling, the CP-653, runs about 18,500 kg (40,800 lb) operating weight; the smaller-numbered CP-643 should weigh somewhat less, though that figure isn't independently confirmed. Check the machine's data plate for the exact number.
What replaced the Caterpillar CP-643?
No model carries the CP-643 name forward as a direct one-for-one replacement. Cat's later single-drum soil compactors adopted different naming schemes entirely, such as the D- and E-series (including the CS-533E/CP-533E) and today's GC-series, rather than continuing the 643 designation.
What CP-643 owners discuss
What's the typical propel/hydraulic complaint on a CP-643, and what usually causes it?
Weak or uneven travel, creeping in neutral, or loss of drive power on grade almost always traces back to the hydrostatic propel circuit: worn pump or drive motor, internal leakage, or a marginal charge pump losing pressure as the unit heats up. On a machine this age, first check hose and fitting condition (vibration works fittings loose and abrades hose jackets over time) before condemning the pump or motor. Have your dealer verify hydrostatic charge and system pressures against spec before replacing major components.
Does the CP-643's drum lose vibration or run rough, and what's the root cause?
Loss of vibration, unstable amplitude, or a growling/knocking noise from the drum is a classic exciter bearing symptom. Low oil level in the vibratory bearing lube reservoir is the number-one cause of premature bearing wear on this style of exciter; once bearings are damaged the eccentric shaft can follow. Owners of this compactor class report catching it early by listening for bearing noise and checking exciter oil level and condition at every service interval rather than waiting for a hard failure.
What quirks show up with the 3304 engine in this compactor, especially on starting and fueling?
Hard starting hot or cold, rough idle, power loss under load, or smoke (black under load, white/grey on cold start) point to fuel system wear rather than the engine itself on a 3304 of this vintage: worn injection pump plungers and transfer pump valves let high-pressure fuel bypass the delivery valves, and water contamination or a weak relief valve makes it worse. The naturally aspirated and turbocharged 3304 variants used across this compactor family share this wear pattern; turbo units add bearing and seal wear in the turbocharger itself at high hours. Isolate a rough cylinder by cracking one injector line at a time before assuming the pump needs a rebuild.
What undercarriage and drum wear patterns are typical on a machine this old?
Padfoot tip wear and drum shell thinning are normal wear items and worth a shell-thickness check, not a red flag by themselves. Bigger concern is drum-end bearing seal leakage — grease or oil weeping at the drum hub — which signals the seals have hardened with age and let contamination into the bearing. The articulation center pin and bushings are the other common wear point: daily greasing is critical on this joint, and neglect shows up as steering play or a clunk on direction change. Have your dealer verify articulation joint play and drum bearing condition before returning the machine to service.
What electrical or charging issues come up on compactors of this vintage?
These machines predate electronic engine controls, so the electrical system is limited to starting, charging, and gauge circuits — and that's where the age-related faults show up: corroded gauge panel connections, weak or misdiagnosed alternator output, and worn neutral start switch contacts. A failing neutral start switch is a safety item since it's meant to prevent starting the machine in gear; treat any starting-in-gear complaint as urgent. Have your dealer verify the neutral start switch and charging circuit before returning the machine to service.
Is overheating a known issue on this compactor, and what should be checked first?
Compaction duty cycles run the engine at sustained load with a lot of ambient dust, so cooling packages on 3304-powered machines of this era are prone to plugged radiator and oil cooler cores over time. Before suspecting a head gasket or water pump failure, clean the cooling package and check the thermostat; a plugged oil cooler core is a common and easily missed cause of a hot-running engine on these machines.
What should a buyer check before purchasing a used CP-643?
Confirm from the ID plate whether the machine is the naturally aspirated or turbocharged 3304 configuration, since parts and performance expectations differ. Run the vibratory system through its amplitude settings and listen for exciter bearing noise. Check drum shell thickness and padfoot condition, and look for oil or grease weeping at the drum-end bearing seals. Work the articulation joint lock and steering through full travel checking for play in the center pin and bushings. Inspect hydraulic hoses and fittings for wear from vibration, and look for smoke or hard starting that points to injection pump wear. Confirm ROPS structure and seatbelt are intact and the neutral start switch works. Have your dealer verify hydraulic pressures, engine compression, and structural/ROPS integrity before finalizing a purchase.
Compiled from owner and technician discussions across the industry — experiences vary by serial range and machine history.
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