00 11... Checking/topping up oil level in rear differential

WARNING: This page is about a different car, the 2010 BMW 550i, 2009 BMW 550i, and 2008 BMW 550i. However, it is still accessible from the selected car via links, so may be relevant.

IMPORTANT: Risk of damage!
To avoid serious damage to the rear differential, it is essential to use only approved gear oils in the differential.

Undo oil filler plug (1).

Check oil level.

If necessary, pour in rear differential oil up to lower edge of opening for oil filler plug (1).

Fig 1: Identifying Oil Filler Plug

Courtesy of BMW OF NORTH AMERICA, INC.

Installation:

Oil filler plug with sealing ring:
Replace sealing ring (1).

Tightening torque: 33 11 3AZ . See REAR AXLE - TIGHTENING TORQUES .
Oil filler plug with O-ring:

Replace oil filler plug (2).

Tightening torque: 33 11 9AZ . See REAR AXLE - TIGHTENING TORQUES .

Fig 2: Identifying Sealing Ring And Oil Filler Plug

Courtesy of BMW OF NORTH AMERICA, INC.