Crankshaft Radial Seal that keeps oil off the alternator belt and hall sensor.When
replacing the oil seal use the appropriate BMW service manual.
This is
a Teflon seal that needs to be pre-formed and installed with the specialty tool
83 30 0 401 574.
It is
installed with the open side of the seal towards the inside of the engine.
Teflon
seals must be clean of all oil/lubricant when installing.