| • | Damaged sealing surfaces |
| • | Damaged bolt hole threads |
| • | Worn or scored bearing race bores |
| • | Loose or restricted ventilation tube |
| • | Porosity |
| • | Damage to the exterior of the case |
| • | Damaged sealing surfaces |
| • | Worn or scored bearing race bore |
| • | Porosity |
| • | Damage to the exterior of the cover |