CATBearing & Bushing

5I7784 Main Bearing Kit — Cat 311 311B

This is a main bearing kit designed to support the crankshaft within the engine block, ensuring proper alignment and minimizing friction during operation. It meets stringent OEM material and dimensional standards, offering superior wear resistance and durability compared to a worn bearing set that can lead to increased vibration and oil pressure loss. Operators may observe a knocking sound from the engine, a significant drop in oil pressure, or increased exhaust smoke when these bearings begin to fail.

Main Bearing Kit – Part No 5I7784 – CAT Spare Part
Part Specifications
BrandCAT
CategoryBearing & Bushing
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

Never strike bearings directly — use a bearing press or driver set. Heat housing (not bearing) to ease installation. Replace bearings in sets where applicable. Check housing bore diameter before fitting — out-of-round bores destroy new bearings.

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 Kit
MaterialSteel alloy with bearing overlay
ApplicationEngine crankshaft support
Service LifeReplace every 5,000 hrs or as needed
CompatibilityOEM specification
ConditionNew — OEM specification aftermarket

Failure Symptoms

The first noticeable symptom of main bearing failure is often a deep knocking sound from the engine's lower end, especially under load. This is typically followed by a significant drop in oil pressure and potentially increased exhaust smoke. Continued operation risks severe damage to the crankshaft and engine block, leading to extensive repair costs.

Installation Tip

Ensure the crankshaft and bearing surfaces are impeccably clean and free from any foreign particles before installation. Avoid using excessive force when seating the bearing shells, as this can lead to deformation and improper oil clearance.

Service Note

Inspect the crankshaft journals for any signs of scoring or wear, and replace the connecting rod bearings simultaneously.