Yanmar 4D94LE Crankshaft YM129902-21050 for Excavator & Industrial Engines

Product Details

Product Overview

This high-precision Yanmar 4D94LE crankshaft (OEM reference: YM129902-21050) is a critical engine component designed for demanding construction and agricultural applications. Manufactured to meet or exceed OEM specifications, this crankshaft ensures reliable power transfer and long service life for Yanmar-powered excavators, tractors, and industrial machinery. We offer global shipping with fast delivery to major industrial hubs in North America, Europe, Asia-Pacific, and the Middle East.

Key Features & Benefits

• Premium Material: Forged from high-strength alloy steel for superior fatigue resistance and durability under heavy loads.
• Precision Engineering: Machined to exacting tolerances for perfect balance, reducing vibration and wear on main bearings and connecting rods.
• Heat-Treated: Induction-hardened journal surfaces provide exceptional wear resistance for extended engine life.
• Direct Fit: Designed as a direct replacement for the original Yanmar 4D94LE crankshaft, requiring no modifications for installation.
• Rigorous Testing: Each unit undergoes dimensional, hardness, and balance checks to ensure flawless performance.

Technical Specifications

OEM Cross-Reference

This crankshaft is a direct replacement for the following OEM numbers:

• Yanmar: YM129902-21050
• Alternative Reference: 129902-21050 (without prefix)

Note: While this is the primary OEM number, always verify compatibility with your specific engine serial number for confirmation.

Compatibility

• Engine Models: Yanmar 4D94LE (all variants including naturally aspirated and turbocharged versions)
• Applications:
  • Excavators (e.g., Yanmar VIO series, B series mini-excavators)
  • Agricultural Tractors (e.g., Yanmar YT, YM series)
  • Industrial Engines (generators, compressors, pumps)
• Year Range: Generally compatible with engines manufactured from the late 1990s to present. Check engine serial number for exact fitment.

Global Supply & Distribution

We are a dedicated global supplier of Yanmar engine components, offering reliable logistics to industrial centers worldwide.

• Shipping: Air freight (DHL, FedEx, UPS) and sea freight (FCL/LCL) available.
• Major Markets: North America (USA, Canada, Mexico), Europe (Germany, UK, France, Netherlands), Asia-Pacific (Japan, Korea, Australia, China), Middle East (UAE, Saudi Arabia), and Africa.
• Delivery: Fast dispatch from stock. Typical transit times: 3-5 days for air freight, 15-30 days for sea freight to major ports (e.g., Rotterdam, Los Angeles, Shanghai, Jebel Ali).
• Export Compliance: All products are packaged and documented to meet international trade standards.

Quality Assurance

• Manufacturing Standard: ISO 9001:2015 certified production facility.
• Testing: 100% dimensional inspection, hardness testing, and dynamic balancing before shipment.
• Warranty: 12-month warranty against manufacturing defects under normal operating conditions.
• Certification: Material test certificates available upon request.

FAQ

Q1: Is this crankshaft a direct fit for my Yanmar 4D94LE engine?
Yes, this is an OEM replacement part (YM129902-21050) designed for the 4D94LE engine. It should be a direct bolt-in replacement. However, we strongly recommend verifying your engine’s serial number and comparing the crankshaft dimensions (main journal and crankpin diameter) with your original part to ensure compatibility, especially if your engine has been previously rebuilt with undersized bearings.

Q2: What should I replace along with the crankshaft during installation?
For a successful rebuild, we recommend replacing the following parts simultaneously: main bearings, connecting rod bearings, thrust washers, and all seals (front and rear main seals). It is also advisable to inspect and potentially replace the oil pump for optimal lubrication. Using new bolts for the main bearing caps and connecting rods is critical for proper torque and safety.

Q3: How can I ensure proper maintenance after installing the new crankshaft?
After installation, perform a break-in procedure as specified in your Yanmar service manual. Use the recommended grade of engine oil (typically 15W-40 for diesel engines) and ensure the oil filter is new. During the first 50 hours of operation, avoid sustained high RPMs and heavy loads. Check for unusual noises or vibrations. Regular oil changes at the manufacturer’s specified intervals will significantly extend the life of the new crankshaft and bearings.