Description
Tatan Machinery supplies professionally remanufactured Caterpillar 3066T diesel engine assemblies (OEM reference: 305-4783 , interchangeable with 1725184 / 138-2098 / 179-1808) configured for CAT 320C and 320C L crawler excavators. Rebuilt strictly to OEM tolerance standards with 100% brand-new internal wear components, this drop-in assembly eliminates field overhaul downtime. This page details first-party rebuild specifications, workshop testing standards, field failure diagnostics, and buyer sourcing guidelines.
Supplier Information & Build Status
| Supplier: | Tatan Machinery (Professional Excavator Parts Supplier) |
| Product Category: | Diesel Engine Assembly / Excavator Engine Parts |
| Engine Model: | Cat® 3066T Turbocharged Direct-Injection Diesel |
| OEM Reference: | 305-4783 |
| Product Build Condition: | Professional Remanufactured to OEM Specs (Genuine Heavy Cast Core + 100% Brand-New Wear Components) |
| Other Parts Condition: | All other excavator components on our site (Hydraulic Pumps, Main Valves, Swing & Travel Motors) are 100% Brand New. |
| Target Machine: | CAT 320C / CAT 320C L Hydraulic Excavators |
🏢 Tatan Machinery Engine Staging & Workshop Facility
Physical inventory storage, engine remanufacturing staging, and pre-export testing facility:
Physical inventory — ready for global crating. Video calls and warehouse visits welcome.
Technical Specifications
| Parameter | Specification Data |
|---|---|
| Displacement | 6.37 Liters (389 cu in) |
| Cylinder Arrangement | Inline 6-Cylinder, 4-Stroke Mechanical Diesel |
| Bore × Stroke | 102 mm × 130 mm (4.02 in × 5.12 in) |
| Fuel Injection System | Mechanical In-line Injection Pump with Electronic Governor Control |
| Aspiration | Turbocharged (Exhaust Driven) |
| Cooling Circuit | Pressurized Water-Cooled with Heavy-Duty Oil Cooler Bundle |
| Standard Machine Match | Caterpillar 320C / 320C L Hydraulic Excavators |
Remanufacturing Standard: What Makes This Drop-In Ready?
This engine is NOT a cheap used/second-hand salvage yard pull. It is thoroughly disassembled, sonically cleaned, re-machined, and assembled with 100% brand-new critical wear components:
- Structural Core Inspection: Engine cylinder block and cylinder head are chemically de-carboned, ultrasonic cleaned, and magnaflux-tested for micro-cracks. Deck surfaces precision ground.
- 100% Brand-New Wear Components Installed: Brand-new pistons, piston ring sets, cylinder liner sleeves, wrist pins, connecting rod bearings, main crankshaft bearings, thrust washers, and complete valve guide seals.
- Forged Crankshaft Re-Machining: Crankshaft journals micropolished and dynamically balanced to factory runout specifications.
- 100% Brand-New Gasket & Seal Kit: Complete front/rear crankshaft oil seals, head gasket, and manifold seals renewed to eliminate field oil/coolant weeping.
- Mechanical Injection Pump & Turbo Overhaul: In-line pump fitted with new plungers and calibrated on a fuel test bench for balanced 6-cylinder fuel delivery.
When to Replace the Cat 3066T Engine on CAT 320C: Diagnostic Criteria
The Caterpillar 320C operates at higher hydraulic relief pressures than previous generations. Under heavy rock excavation or continuous breaking, severe wear makes field overhauls inefficient:
- Injection Pump Bogging & Hot-Stall: Internal fuel plunger leakage once diesel exceeds operating temperature, causing rpm drops when curling the bucket or lifting the boom under full load.
- Cylinder Sleeve Wear & Severe Crankcase Blow-by: Piston ring gap enlargement venting blue oil smoke through the breather tube, resulting in excessive lube oil consumption and hard cold-starts.
- Spun Connecting Rod Bearings: Lube oil shearing or thermal breakdown causing bearing seizure, scoring crankshaft rod journals beyond standard regrind specifications.
- Cylinder Head Inter-Port Cracking: Thermal fatigue causing cracks between valve seats and fuel injector bores, leaking combustion pressure into the radiator overflow bottle.
Workshop Testing Standards (Pre-Delivery Inspection)
Every remanufactured Cat 3066T for CAT 320C undergoes mandatory pre-shipment quality verification:
- Manual Crankshaft 720° Barring Test: Smooth rotation verification without valvetrain binding or mechanical interference.
- Mechanical Fuel Pump Timing & Plunger Check: Verification of fuel spill timing and injection nozzle atomization pattern.
- Lube Oil Gallery Pressure Priming: Pre-filling the oil circuit to confirm pressurized flow through main journals and turbocharger feed lines.
- Block & Head Pneumatic Leak Hold Test: Air hold test to guarantee oil cooler bundle and cylinder head gasket sealing integrity.
- Flywheel Coupler Concentricity Dial Check: Ensuring 100% true alignment for the hydraulic main pump drive coupling.
📹 Live 3066T Engine Workshop Inspection Video
Watch our workshop technician verify rotation, stamped serial numbers, and mounting ports:
✓ Real physical unit filmed at Tatan Machinery workshop
Export Heavy-Duty Packaging Process
To protect the mechanical fuel injection pump, throttle sensor linkages, and turbocharger during ocean transit:
- Internal & External Anti-Rust Preservation: All raw machined surfaces, crankshaft snout, and flywheel teeth coated with high-grade anti-corrosion grease.
- Dust Caps on All Openings: Intake manifold, exhaust elbow, water inlets, and fuel feed fittings sealed with heavy-duty protective plugs.
- Direct Sump-Skid Bolting: The engine is anchored securely to heavy timber base skids through rigid mounting brackets.
- ISPM 15 Fumigation-Free Solid Crate: High-density export plywood crate secured with galvanized steel strapping.
Actual export wooden crate packaging and internal skid bracing for Cat 3066T
Global Shipping & Customs Documentation
Fast, reliable dispatch tailored for commercial contractors and parts wholesalers worldwide:
- Emergency Machine Down (AOG Freight): Priority air cargo via DHL Aviation, FedEx Heavy Cargo, or direct airline belly freight within 3–7 business days.
- Ocean Container Freight (LCL / FCL): Consolidated container shipping to all major commercial seaports worldwide.
- Complete Export Documents: Commercial Invoices with correct HS Code (8408.20), Packing Lists, and Certificates of Origin for smooth customs clearance.
Container loading and air freight dispatch supported by global logistics partners
Critical Installation Guidelines (320C Technician Checklist)
To prevent instant failure of the newly installed engine assembly, field technicians MUST adhere to the following steps:
- MANDATORY: Radiator & Oil Cooler Flushing: If the old engine experienced bearing seizure or cracked pistons, metal shavings reside in the external oil cooler core and hoses. You MUST thoroughly flush or replace the oil cooler before connecting oil lines to the new engine!
- Pre-Lube the Engine: Pre-fill the new oil filter with 15W-40 oil. Disconnect the manual fuel shut-off solenoid wire and crank the starter motor in 10-second bursts until the oil pressure light turns off or the gauge rises. NEVER fire up a dry engine!
- Mechanical Fuel Pump Air Bleeding: Pump the hand primer on the fuel filter base until clear diesel emerges without bubbles from the injection pump bleeder screw. Air locks will starve the mechanical plungers of initial lubrication.
- Check Flywheel Coupling Damper: Inspect the rubber drive coupling connecting to the hydraulic pump (SBS80 / K3V112DT). Hardened or cracked rubber elements cause excessive crankshaft torsional vibration and rear main seal leakage.
- Throttle Linkage & Governor Motor Calibration: Verify that the electronic governor stepper motor on the 320C cycles smoothly through all dial positions without binding the mechanical pump lever.
Buyer Frequently Asked Questions (Purchasing FAQ)
Q: Is this 3066T engine brand new or remanufactured? What is the actual build quality?
A: This engine assembly is professionally remanufactured strictly to Caterpillar OEM tolerances. We do not sell worn salvage yard engines. The cast iron block, cylinder head, and forged crankshaft undergo ultrasonic cleaning, crack detection, and precision machining. 100% of internal wear parts are replaced with brand-new components (new pistons, rings, liners, bearings, valves, and a complete gasket seal kit). It provides the exact performance and lifespan of an OEM build at a fraction of dealer pricing.
Q: Are all other products on your website remanufactured as well?
A: No. Only our heavy diesel engine assemblies are professionally remanufactured. All other excavator spare parts supplied by Tatan Machinery—including our hydraulic main pumps, main control valves, final drive travel motors, swing motors, and undercarriage components—are 100% Brand New (OEM-Grade Aftermarket) ready for immediate jobsite duty.
Q: CAT 320C excavators have various serial prefixes (AMC, ANH, BCK, BEA, BPR, BRX, RAW, etc.). How do you ensure it will fit my chassis?
A: Different 320C manufacturing origins (e.g., Japan vs. US/European builds) can feature different throttle stepper motor brackets, oil pan depths, or flywheel housing bolt patterns. We eliminate guesswork: send your 320C serial number (PIN) from the cab tag and clear photos of your old engine’s pump side and flywheel face to Gavin. We cross-verify the engineering arrangement in the official Caterpillar SIS database within 10 minutes.
Q: Can I see live photos and stamped block numbers of the actual engine before paying?
A: Absolutely yes. Prior to balance payment and dispatch, we send clear photos and live video of the specific unit assigned to your order. You will see the stamped serial numbers, mechanical injection pump tags, flywheel teeth, and the complete wooden box packaging process.
Q: What happens if the crate is damaged during sea freight, and what customs paperwork do you provide?
A: Every shipment from Tatan Machinery is protected by full commercial marine cargo insurance. The engine is bolted down directly onto internal skids within a fumigation-free solid plywood crate. We supply commercial invoices with accurate HS Codes (8408.20), detailed packing lists, and Certificates of Origin for smooth customs clearance at your destination port.
🔗 Frequently Purchased Together with CAT 320C Diesel Engine:
- MAIN VALVE:
Main Control Valve Assembly for Caterpillar 320C
100% Brand New - HYDRAULIC PUMP:
SBS80 / K3V112DT Hydraulic Main Pump Assembly for Caterpillar 320C
100% Brand New - SWING MOTOR:
M2X150 Swing Motor Assembly for Caterpillar 320C
100% Brand New - BRAND CATALOG:
View All Caterpillar Excavator & Heavy Equipment Parts Collection
Get Wholesale Factory Quote for 3066T 305-4783 Engine Assembly
Looking for direct factory pricing, stock availability, or technical verification for Cat 3066T engines? Contact senior specialist Gavin now!
💡 Fast Quote: Send your engine serial number or nameplate photos for an accurate match within 10 minutes!
* Note: Wholesale Reference Price Starts From $300.00. Please contact Gavin for a final customized quote based on freight destination and configuration.
* Note: Wholesale Reference Price Starts From $300.00. Please contact Gavin for a final customized quote.
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