Indications:

• Increase in bearing temperature due to reduced oil flow and friction.
• Abnormal noise from crankcase during turning.
• Increased amperage/power consumption of turning gear motor during rotation.
• Rise in lubricating oil temperature.
• Dark brown appearance of lubricating oil due to overheating and oxidation.
• High oil mist content inside crankcase, indicating excessive wear or overheating.
• Presence of white metal particles in lubricating oil analysis.

Possible Effects:

• Excessive heat generation leading to melting/wiping of bearing white metal.
• Metal-to-metal contact causing surface damage (scoring) of crankpin and bearing.
• Seizure of bearing and crankshaft, leading to alarms and engine slowdown/trip.
• Oxidation and sludge formation in lubricating oil.
• Permanent damage and total failure of the bearing.

Indications:

• Drop in lubricating oil pressure due to excessive leakage.
• Knocking sounds from piston and other reciprocating parts.
• Increased bearing temperature.
• Noisy operation with irregular engine running.
• Presence of white metal particles in lubricating oil analysis.
• Increased engine vibrations due to imbalance.

Possible Effects:

• Hydrodynamic oil film fails to form properly, causing metal-to-metal contact.
• Accelerated wear and damage to bearing surfaces.
• Irregular engine speed and rough running.
• Higher vibrations and eventual fatigue damage.
• At extreme conditions, overheating, alarms, slowdown, and seizure.

Indications:

• Variation in bearing temperatures along the crankshaft.
• Deviations observed in crankshaft deflection readings.
• Uneven bearing wear and changes in bearing clearances.
• Bearings overheating, wiping, and possible cracks.
• White metal debris observed in lubricating oil analysis or in crankshaft fillets.

Possible Effects:

• Uneven load distribution leading to bearing damage.
• Edges of bearings worn out and wiped.
• Increased vibration and noise during engine operation.
• Fatigue cracks in crankshaft fillets.
• Long-term misalignment may cause permanent bending of crankshaft.

• Main Bearing (Top clearance): Max 0.85 mm, Min 0.55 mm
• Top End Bearing (Top clearance): Max 0.70 mm, Min 0.35 mm
• Bottom End Bearing: Max 0.72 mm, Min 0.48 mm