4BT 4D102 Crankshaft 3907803 3908031 3929036 for Cummins Engine Construction Agriculture GenSet

Product Details

Product Overview

This high-quality aftermarket crankshaft, identified by OEM part numbers 3907803, 3908031, and 3929036, is specifically designed for the Cummins 4BT and 4D102 diesel engine platforms. As a critical rotating component, this crankshaft converts the linear motion of the pistons into rotational torque, directly driving the engine’s power output.

Manufactured to OEM specifications, this crankshaft is commonly used in a wide range of heavy-duty applications, including construction machinery, agricultural equipment, industrial generators, marine propulsion, and material handling vehicles. It is a direct replacement part, ensuring a precise fit and reliable performance for engine rebuilds or repairs.

Key Features & Benefits

• OEM Standard Dimensions: Manufactured to strict OEM size specifications, guaranteeing a direct bolt-in fit without the need for modifications, reducing installation time and labor costs.
• Superior Material Strength: Constructed from high-strength alloy steel to withstand the extreme torsional stresses and fatigue cycles of high-torque diesel engines, ensuring long service life.
• Precision Machining: All journal surfaces are precision-ground and polished to exacting tolerances for optimal oil film retention and reduced friction, enhancing engine efficiency and durability.
• Rigorous Quality Testing: Each crankshaft undergoes a comprehensive machinery test report and video outgoing inspection to verify dimensional accuracy, hardness, and balance, providing complete fit confidence.
• Versatile Application: Suitable for a broad spectrum of industrial sectors including construction, agriculture, genset, and marine, making it a versatile stock item for parts distributors.
• OEM Service Available: We offer OEM/ODM services for custom branding or packaging requirements, supporting your specific inventory and customer needs.

Technical Specifications

OEM Cross-Reference

This crankshaft is a direct replacement for the following original equipment manufacturer (OEM) part numbers. Please verify your existing part number against this list for compatibility.

• Cummins OEM: 3907803, 3908031, 3929036

Note: This is a high-quality aftermarket replacement part, not an original OEM part. It is designed to meet or exceed OEM performance standards.

Compatibility

This crankshaft is specifically engineered for the Cummins 4BT (4-cylinder, Turbocharged) and 4D102 engine families. It is commonly used for:

• Construction Equipment: Backhoe loaders, excavators, compactors, and skid steer loaders.
• Agricultural Machinery: Tractors, harvesters, and irrigation pumps.
• Industrial Applications: Forklifts, aerial work platforms, and generator sets (Gensets).
• Marine & Handling: Small marine auxiliary engines and material handling equipment.

Fitment is inferred based on engine model. Always confirm physical compatibility with your specific engine serial number before installation.

Global Supply & Distribution

As a leading supplier based in Guangdong, China, we offer efficient worldwide shipping to all major industrial markets. Our logistics network ensures fast and reliable delivery to:

• North America: Major ports including Los Angeles, Houston, and New York.
• Europe: Rotterdam, Hamburg, and Felixstowe.
• Asia-Pacific: Singapore, Dubai, and major Chinese ports.
• Middle East & Africa: Jebel Ali, Durban, and Mombasa.

We have extensive export experience and comply with international trade regulations to ensure smooth customs clearance. Bulk orders and consolidated shipping are available to reduce per-unit freight costs for B2B buyers.

Quality Assurance

Every crankshaft is manufactured in ISO-certified facilities using advanced forging and machining processes. Our quality control system includes:

• Material Certification: All raw materials are tested for chemical composition and mechanical properties.
• Dimensional Inspection: 100% inspection of main journals, pin journals, and keyways using CMM (Coordinate Measuring Machine) equipment.
• Dynamic Balancing: Each crankshaft is dynamically balanced to minimize vibration and ensure smooth engine operation.
• Warranty: Backed by a 6-month warranty against manufacturing defects, with continued online technical support after the warranty period.

FAQ

Q: How can I confirm this crankshaft fits my specific Cummins 4BT engine?
A: Please verify your engine’s serial number and the existing crankshaft part number. This crankshaft is a direct replacement for OEM numbers 3907803, 3908031, and 3929036, which are standard for the 4BT and 4D102 models. If your part number matches one of these, it is compatible. For non-standard applications, please contact our support team with your engine details for verification.

Q: Does this crankshaft come with bearings or a thrust washer?
A: This listing is for the crankshaft only. Main bearings, connecting rod bearings, and thrust washers are typically sold separately to allow you to select the correct undersize for your rebuild. We recommend purchasing a complete bearing set from your engine supplier to match the crankshaft journal condition.

Q: What is the recommended installation procedure for this crankshaft?
A: Installation should be performed by a qualified diesel mechanic. Key steps include: 1) Thoroughly clean the crankshaft and engine block. 2) Lubricate all journal surfaces and bearings with clean engine oil during assembly. 3) Torque main bearing caps to the manufacturer’s specifications in the correct sequence. 4) Check crankshaft end-play. Always consult your Cummins 4BT service manual for exact torque values and procedures.