The Main Bearing 0.020 Shell, also known as part number AR12272, is a component in a truck's engine that is responsible for supporting the crankshaft and reducing friction between it and the engine block. It is called a "shell" because it has a thin metal layer that encases the bearing material, providing additional strength and durability. The 0.020 measurement refers to the thickness of this shell, which can vary depending on the specific engine model. A properly functioning main bearing helps ensure smooth operation of the engine and prolongs its lifespan. If damaged or worn out, it can cause excessive noise or vibrations in the engine, which may lead to more serious issues if not addressed promptly.
| AR12272 | Main Bearing (020) Set | |
| PN | NAME | QTY |
| 205112 | BEARING,THRUST | 4 |
| 205142 | BEARING,MAIN | 5 |
| 205152 | BEARING,MAIN | 5 |
| 205162 | BEARING,MAIN | 2 |
| 205172 | BEARING,MAIN | 2 |