Connecting rod and main bearings — inspection and alignment (Peugeot 305)

1. New bearings have a highly polished surface that becomes matte gray over time. Bearings must be free of pits, ridges, gouges or scratches. Even if the bearing shells look good, we recommend replacing them anyway, especially if you are removing the crankshaft anyway. In any case, the liners need to be replaced if they are damaged or the crankshaft is subject to regrinding.

2. If the crankshaft is in good condition and you are only going to replace the bearing shells, you should check if the crankshaft has been reground before. This can be recognized by the installed bearing shells - if the new shells that you are going to install have the same numbers as the old shells that are on the engine, then the shaft has not been reground.

3. Connecting rod bearings wear faster than main bearings. The failure of the connecting rod bearings is accompanied by a knock from the crankshaft side and a slight drop in oil pressure. The failure of the main bearings is accompanied by vibration, which can increase markedly with increasing engine speed. If any of these signs appear, you should immediately turn off the engine, because. its operation with failed bearings can lead to serious problems.