3802070 3939859 4893693 Main & Rod Bearing Set for Cummins QSB4.5 4D107 Diesel Engine

Product Details

Product Overview

This comprehensive bearing set includes both main crankshaft bearings (Part No. 3802070) and connecting rod bearings (Part Nos. 3939859 & 4893693), specifically designed for the Cummins QSB4.5 and 6D107 (4D107) series diesel engines. Manufactured to OEM specifications, this kit provides a complete solution for engine rebuilds and overhauls, ensuring precision fitment and reliable performance in demanding applications.

These engine bearings are critical components that support the rotating assembly within the engine block. The set includes all necessary bearings for a full lower-end rebuild, reducing the complexity of sourcing individual parts. Ideal for use in construction equipment, agricultural machinery, industrial generators, marine vessels, and material handling equipment powered by these Cummins diesel platforms.

Key Features & Benefits

• Complete Rebuild Kit: Includes both main bearings (3802070) and rod bearings (3939859/4893693) for a comprehensive lower-end service.
• OEM Specification Fitment: Manufactured to strict OEM size standards, ensuring proper oil clearance and crankshaft support without the need for selective fitting in standard applications.
• High Load Capacity: Engineered to withstand the high cylinder pressures and torque outputs of turbocharged Cummins QSB4.5 diesel engines.
• Durable Tri-Metal Construction: Provides excellent fatigue resistance and embedability for contaminants, extending bearing life in harsh operating conditions.
• Corrosion Resistance: Advanced overlay plating protects against acidic oil degradation and extends service intervals in high-hour applications.
• Application Versatility: Suitable for a wide range of equipment from agricultural tractors to marine gensets, reducing inventory complexity for fleet operators.
• Verified Quality: Each bearing set undergoes dimensional inspection and material verification before shipment, with outgoing video inspection available upon request.

Technical Specifications

OEM Cross-Reference

This bearing set directly replaces the following Cummins genuine part numbers:

• Main Bearing (Upper/Lower): Cummins 3802070
• Connecting Rod Bearing: Cummins 3939859
• Connecting Rod Bearing (Alternative): Cummins 4893693

Note: These parts are aftermarket replacements manufactured to OEM specifications. Always verify your engine block stamping and crankshaft journal condition before ordering to ensure correct size selection.

Compatibility

This bearing set is commonly used for the following engine platforms and applications:

• Engine Models: Cummins QSB4.5 (4.5L), Cummins 4D107 / 6D107
• Construction Equipment: Excavators, wheel loaders, bulldozers, and skid steers
• Agricultural Machinery: Tractors, harvesters, sprayers
• Industrial: Generator sets, air compressors, pumps
• Marine: Auxiliary engines, propulsion systems
• Material Handling: Forklifts, telehandlers, reach stackers

Global Supply & Distribution

We maintain a robust global logistics network to serve B2B clients across all major industrial markets:

• North America: Regular shipments to Los Angeles, Houston, Chicago, Toronto, and Vancouver ports with 7-12 day transit times.
• Europe: Direct distribution to Rotterdam, Hamburg, Antwerp, and Felixstowe for quick clearance into EU markets.
• Asia-Pacific: Express delivery to Singapore, Sydney, Shanghai, and Dubai within 5-8 working days.
• Middle East & Africa: Dedicated routes to Jebel Ali (Dubai), Jeddah, and Durban with customs documentation support.
• South America: Regular consolidation services to Santos, Callao, and Buenos Aires.

We offer flexible shipping options including air freight, sea freight (FCL/LCL), and express courier services. All international orders include complete commercial invoices, packing lists, and certificates of origin for smooth customs clearance.

Quality Assurance

Our manufacturing facility in Guangdong, China operates under strict quality control protocols:

• Each bearing set is 100% dimensionally inspected using CMM (Coordinate Measuring Machine) equipment.
• Material composition is verified through spectrometer analysis to ensure proper alloy ratios.
• Surface finish and overlay thickness are checked against OEM blueprints.
• All products carry a 6-month warranty against manufacturing defects.
• Machinery test reports and video outgoing inspection records are available upon request for quality verification.
• After-warranty online technical support is provided for installation guidance and troubleshooting.

FAQ

Q1: Will these bearings fit my Cummins QSB4.5 engine without modification?
These bearings are manufactured to OEM standard size specifications for the Cummins QSB4.5. However, proper fitment depends on your crankshaft journal condition. We recommend measuring your crankshaft journals for out-of-roundness and taper before installation. If your crankshaft has been reground, you will require undersized bearings (e.g., -0.25mm or -0.50mm), which are not included in this standard-size set.

Q2: What is the correct installation procedure for these tri-metal bearings?
Installation should follow standard diesel engine rebuild procedures: Clean all bearing saddles and caps thoroughly. Apply clean engine oil to the bearing back and journal surfaces. Ensure bearing tangs are properly seated in the saddle grooves. Torque main bearing caps and rod caps to Cummins factory specifications using a calibrated torque wrench in the correct sequence. Always plastigauge the oil clearance (target: 0.05-0.10mm for main bearings, 0.04-0.08mm for rod bearings).

Q3: How do I identify whether I need main bearing 3802070 or connecting rod bearings 3939859/4893693?
Main bearing 3802070 is installed in the engine block and main bearing caps supporting the crankshaft. Connecting rod bearings 3939859 (and its alternative 4893693) are installed in the connecting rod big-end journals. If you are replacing both, order this complete set. For partial rebuilds, verify the part numbers stamped on your original bearing shells. The difference between 3939859 and 4893693 is typically a manufacturing revision; both are interchangeable for the same application.