Ford D2RY-6211-B Connecting Rod Bearing

Lack of lubrication (or lubrication breakdown) has a number of interrelated causes. Excessive heat (which thins the oil), overloading (which squeezes the oil from the bearing face), and oil leakage or throw off (from excessive bearing clearances, worn oil pump, or high engine speeds) all contribute to lubrication breakdown. Blocked oil passages, which usually are the result of misaligned oil holes in a bearing shell, will also oil starve a bearing and destroy it. When lack of lubrication is the cause of bearing failure, the bearing material is wiped or extruded from the steel backing of the bearing. Temperatures may increase to the point where the steel backing turns blue from overheating.

Lack of lubrication can result from excessive heat (which thins the oil), overloading (which squeezes oil from the bearing face), oil leakage or throw off, and blocked oil passages due to misaligned oil holes in a bearing shell. When lubrication fails, the bearing material may be wiped or extruded from the steel backing, and temperatures can rise to the point where the steel backing turns blue from overheating.

Driving habits, such as full-throttle, low-speed operation and short trips, can affect bearing life by inducing high loads, flexing, and corrosion.

Excessive heat (which thins the oil), overloading (which squeezes the oil from the bearing face), and oil leakage or throw off (from excessive bearing clearances, worn oil pump, or high engine speeds) all contribute to lubrication breakdown. Blocked oil passages, usually the result of misaligned oil holes in a bearing shell, will also oil starve a bearing and destroy it.

It is recommended to replace the main and connecting rod bearings with new ones.

Dirt and other foreign particles can get into the engine in a variety of ways. They may be left in the engine during assembly, pass through filters or the PCV system, get into the oil, and from there into the bearings. Metal chips from machining operations and normal engine wear are often present. Abrasives are sometimes left in engine components after reconditioning, especially when parts are not thoroughly cleaned using the proper cleaning methods.

Even though the main and connecting rod bearings should be replaced with new ones during the engine overhaul, the old bearings should be retained for close examination, as they may reveal valuable information about the condition of the engine (Typical bearing failures).