Rod, Main, Cam, And Engine Bearings

Bearings fill the gap between the crankshaft and engine block, crankshaft and connecting rods, as well as the camshaft and engine block. They also provide the proper support to keep all of the parts in line and to handle the stress caused by the force resulting from combustion in the cylinders and high rpm use. In addition, bearings keep clearances uniform to prevent any noises caused by gaps and quickly wearing components.

Replacing main and rod engine bearings when they have worn from normal wear and before they are spun (damaged to the point that replacement is required and damage to other components can occur) prevents further damage that can be caused to other engine parts. This can include connecting rods, engine block, piston, crankshaft, main caps, and other components. If engine bearings are worn enough that metal and contaminants get into the oil and don't get caught in the filter they can cause damage to cylinder walls and other internal components that are exposed to oil and bearing material.

A rod bearing is a circular automotive engine component with two halves that has a surface designed to allow the connecting rod to rotate over the crankshaft with reduced friction and to help keep it in the same place in relation to the other connecting rods. It is designed to wear before the crankshaft to reduce cost.

Engine bearings are circular components, either in one or two piece designs, that are designed to allow rotation inside them such as a crankshaft or camshaft. Bearings require oil to reduce heat and friction that will lead to wear.

Depending on the engine application, the steps to replace an engine rod bearing will vary. However, in most cases, the first step is to remove the oil pan. Having the engine out of the vehicle will make it easier and in some cases will be necessary. However, for the lucky few, replacing rod bearings without removing the engine is possible. The next step is to rotate the crankshaft so that the connecting rod is in the furthest down position. This will allow room for the piston and connecting rod to move up in the cylinder and give room for bearing replacement. Then, remove the connecting rod bolts along with the cap, noting the position to assemble everything exactly as it was taken apart. The replacement rod bearings are put in place along with Plastigauge to confirm the correct clearances next. Once this is confirmed, the rod bolts can be properly torqued and the rest of the engine can be reassembled.

Rod bearing replacement cost (two halves) for the bearing itself can run anywhere from under $5 to under $50 each depending on the application and engine. The labor cost for rod bearing replacement can vary greatly (like the other engine bearings replacement cost), depending on the application, if there was rod bearing failure (with resulting engine damage), and the person or shop doing the work as the number of hours and labor rate will change.