Special tools required:

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27 1 440

IMPORTANT: After completing work, check gear oil level and top up if necessary. See 27 00 ... Replenishing / Changing Transfer Case Oil (ATC 300)
Use only the approved transmission oil in this transfer case.

Necessary preliminary tasks:

Remove transfer case. See 27 10 020 Installing Replacement Transfer Case (ATC 300)

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: Identifying 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 In Output Flange

Courtesy of BMW OF NORTH AMERICA, INC.

Installation:

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

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

Fig 4: Identifying Radial Shaft Seal And Special Tool

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 Screwdriver
Courtesy of BMW OF NORTH AMERICA, INC.