2721020 Replacing radial shaft seal for output flange, automatic (ATC 300): Notes

WARNING: This page is about a different car, the 2011 BMW 328xi, 2010 BMW 335xi, 2010 BMW 328xi, 2009 BMW 335xi, and 2009 BMW 328xi. However, it is still accessible from the selected car via links, so may be relevant.

IMPORTANT: After completing work, check GEAR OIL LEVEL and top up if necessary.
Use only the approved gear oil in the transfer case. See TRANSFER BOX - OPERATING FLUIDS .

Necessary preliminary tasks:

Remove TRANSFER BOX

Release retaining ring (1).

Fig 1: Identifying Retaining Ring

Courtesy of BMW OF NORTH AMERICA, INC.

Release output flange with three-claw extractor tool. Lever radial shaft seal out of housing with a suitable tool.

IMPORTANT: Do not damage housing.

Fig 2: Removing Output Flange With Three-Claw Extractor Tool

Courtesy of BMW OF NORTH AMERICA, INC.

Installation:

Replace O-ring in output flange.

Check that O-ring is in correct position.

Fig 3: Identifying O-Ring

Courtesy of BMW OF NORTH AMERICA, INC.

Installation:

Coat sealing lips of new radial shaft seal with clean transmission oil.

Drive in radial shaft seal with special tool 27 1 440.

Fig 4: Installing Radial Shaft Seal With Special Tool 27 1 440

Courtesy of BMW OF NORTH AMERICA, INC.

Installation:

Push on output flange
Press down output flange using 2 screwdrivers
Fit washer
Continue pressing output flange down until retaining groove is completely visible
Fit retaining ring

Fig 5: Pressing Down Output Flange Using Screwdrivers
Courtesy of BMW OF NORTH AMERICA, INC.