Connecting rod bushings Nissan 1963-1980 SD20, SD33 ACL

The big end bush is a piece metal tube pressed into the connecting rod head, adjacent to the piston pin. Works in extreme conditions as a sliding bearing.
Use of oil of wrong viscosity, oil deficiency, low pressure in the lubrication system, too high load on cold engine, neglect of oil change intervals or wrong mounting of the connecting rod cause excessive load on the bushings, their faster wear.
A steady and steady noise when idling indicates the need to replace the bushing immediately. with replacement may lead to seizure of the element, which damages the entire connecting rod.