Genuine BMW M3 Pilot Bearing

BMW M3 Pilot Bearing Parts Questions & Experts Answers

• Grooved Ball Bearing
  11-21-1-720-310
  Q: What is the purpose and location of the pilot bearing in a BMW M3's transmission system?

  A: The pilot bearing is located at the end of the crankshaft and supports the transmission input shaft to maintain alignment. If the bearing seizes, the clutch will not disengage properly and the transmission may grind or fail to shift into gear. In some cases, replacing the pilot bearing can resolve transmission issues. It is recommended to replace the pilot bearing when replacing the clutch and release bearing. If the bearing is a sealed roller bearing, it cannot be serviced and must be replaced if defective. During inspection, check for excessive play, roughness, or binding in the inner race of the bearing. If any of these symptoms are present, or if the bearing is physically damaged or rusty, it should be replaced. The pilot bearing is considered a wear item and should be replaced whenever the clutch disk and Pressure Plate are replaced. To remove and install the bearing, remove the transmission and clutch assembly. Use a bearing puller and slide hammer to remove the bearing, noting the order of washers and spacers. Clean the crankshaft bore and inspect the bearing for reuse. Lubricate the cleaned or new bearing with approved grease and drive it into the crankshaft bore using a suitable driver or a socket and hammer. If applicable, install the washers and spacers onto the crankshaft and clean any excess grease. Finally, install the clutch and transmission assemblies.