CATUndercarriage

1280400 Main Bearing — Cat 140H 143H

This main bearing is a critical engine component, designed to support the crankshaft and reduce friction within the engine block. Manufactured to precise specifications, it ensures proper crankshaft rotation and oil film integrity, unlike worn bearings that allow metal-to-metal contact. Operators may hear a distinct knocking or rumbling sound from the engine, experience a drop in oil pressure, or observe increased engine vibration when these main bearings begin to fail.

Main Bearing – Part No 1280400 – CAT Spare Part
Part Specifications
BrandCAT
CategoryUndercarriage
ConditionAftermarket — OEM Specification
DispatchSame-day from Mumbai (before 3 PM IST)
GST InvoiceAvailable — all orders
Export DocsCommercial invoice, packing list, COO

Compatible Models

Always verify with serial number before ordering.

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Installation & Application Notes

Cross-reference part number with serial number before ordering to confirm fitment. Keep original parts until new ones are confirmed correct. Record part numbers replaced for future reference.

Always consult the OEM service manual for model-specific torque values and procedures. WhatsApp our technical team if you need fitment guidance.

Part TypeMain Bearing
MaterialBabbitt-lined Steel
ApplicationEngine Crankshaft Support
Service LifeReplace during engine overhaul or if worn
CompatibilityOEM specification
ConditionNew — OEM specification aftermarket

Failure Symptoms

The first indication of failing main bearings is often a deep knocking sound from the engine, particularly noticeable under load. If ignored, the bearing clearance will increase, leading to reduced oil pressure and potential crankshaft damage. Severe main bearing failure can result in catastrophic engine damage and costly repairs.

Installation Tip

Ensure the crankshaft journals and bearing surfaces are meticulously clean and properly lubricated with clean engine oil before installation. Never reuse old bearing shells, and always torque main bearing caps to the manufacturer's specifications.

Service Note

Inspect the crankshaft journals for wear or damage, and check connecting rod bearings when replacing main bearings.