Bearing pitting in rod bearings can be caused by several factors. One common cause is metal fatigue, which occurs due to repeated stress on the bearing, leading to pitting or flaking and premature failure. Another cause is the presence of hard particles, such as metal chips or dirt, rolling through the bearing, which can bruise the surfaces and cause pitting.
Additionally, improper lubrication can lead to increased friction, overheating, and premature wear, contributing to pitting. Contaminants in the lubricant can also cause abrasive damage, leading to pitting and premature wear.
I got this off a quick internet search 🙂