This is critical during an engine overhaul, whereby replacement of main and connecting rod bearings needs to be done but the old bearings would be used in investigating the engine as they may give information of the engine condition. Failure may be caused by several problems and they include lack of lubrication, dirt contamination, engine overloading and corrosion among others that should be resolved before reassembling to prevent them in the future. In changing the bearings, they must be taken out of their places and put on an inviting surface to enable comparison of any issues with the crankshaft journal. The engine can receive the contaminants either in a form of assembly remnants, filters or PCV system, and can contain metal chips and abrasives that have been machined or reconditioned. These foreign objects can attach themselves in the bearing material, whereas larger debris can result in scoring or gouging. In order to avoid such failures, it is important to clean all the components and change the oil and filter frequently. Excessive heat, overloading, or leakage of oil might cause lubrication problems, which cause serious harm whereby the bearing material can be wiped out, and overheating can occur. Also driving techniques play a part in bearing longevity; the low speed on high gear operation may result in excessive loads, and corrosion may occur because of inadequate heat because of limited trips. Finally, wrong installation of bearings may also lead to failure because when the bearings are tight, the oil supply will be starved and trapped debris may form high spots that will undermine the integrity of the bearing.