When having an engine overhaul, it is crucial to install fully new main and connecting rod bearings, always keeping the old ones to study, since they could show an insight into the condition of the engine. Being a leading cause of failure, improper lubrication, dirt/foreign particles, engine overloading, corrosion and which requires redress, prior to re-assembling the function to avoid future occurrence. When checking out bearings, move them to a clean surface, with the crankshaft parts in position, to ensure that any problem is correlated with that journal of the crankshaft. Foreign particles may find their way into the engine when assembling, through filters, or when machining, and are likely to become embedded into the soft bearing material, whereas larger particles may cause scoring or gouging. Thorough parts cleaning and frequent oil and filter changes are important to prevent such failures. The loss of lubrication may be caused by too much heat, overloading, oil seepage or blocked lubrication passages giving way to severe destruction whereby the bearing material is abraded off its support. Driving behavior is also a major issue affecting bearing life; extreme, high-speed, full-throttle operation can produce high loads stressing the film to cause fatigue failure, whereas simple short journeys can result in corrosion, as the lack of heat prevents the film to maintain its temperature. There has also been the inadequate fitting of bearings which lead to oil starvation or high spots as a cause of failure.