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ENGINE BEARINGS FAILURE TYPE . . . |
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Normal Bearing Fails : This bearings shows normal fail like small hairline cranks on bearings surface, with relatively few signs of foreign particles are normal signs of bearing fails. Fatigue Fails : Worn areas located only on the top bearing in the connecting rod, or on the lower bearing in the block are a sign of fatigue (bearing overload) fails. Excessive loads caused by detonation due to advanced ignition, poor quality fuel, and excessive compression may lead to this type of damage. Lugging the engine when pulling heavy load can also contribute to bearing fatigue. Dirt Embedment (Dust) : This type of bearing damage is caused by dirt or dust. Inadequate maintains because of infrequent oil changes and lack of maintenance to the air filter contribute sand and dust particles into the oil. Unclean conditions when assembling an engine during an overhaul will also result in bearing damage of this type fails. De alignments : Connecting rod misalignment causes this type of damage. Misalignment may be caused by distorted bearing bore, bent connecting rod, or combustion problems causing irregular side loading on the piston and connecting rod may cause this type of fails. Oil Starvation : This shows a bearing suffering from excessive friction and fusing signs caused by lack of oil. Some of the causes of lubrication failure are a blocked oil filter cartridge, broken oil line, failure of the oil pump, or excessively low oil level in the working engine. Cavitations : This bearing shows signs of erosion caused by noxious acids in the oil. Some of the causes are extreme flow of gases caused by blow by fuel pump leaking fuel into the crankcase, oil contamination by coolant, and excessive operating temperatures. distorted Crank Case : Depending on the type of block distortion, the bearing wear will be most extreme on the tops of the bearings. The block straightness must be checked and align honed or bored to correct this problem. Distorted Crankshaft : Bearing failure which produces severe wear on both the upper and lower halves of the bearing are usually caused by excessive distortion of the crankshaft. This may be a result of unusually high loading conditions and excessive speed. A bent crankshaft will also produce this type of bearings fails. |