8HP Transmission: Fluid Loss From Cooler Line Connections - from service bulletin SI B24 02 15 (6/2015)

Applies to the following models with N20, N26, or N55 engine and 8HP transmission:

- E84 (X1)

- E89 (Z4)

- F22 (2 Series Coupe)

- F23 (2 Series Convertible)

- F30 (3 Series Sedan)

- F31 (3 Series Sports Wagon)

- F32 (4 Series Coupe)

- F33 (4 Series Convertible)

- F34 (3 Series Gran Turismo)

- F36 (4 Series Gran Coupe)

Situation: 

There is a transmission fluid leak in the area around the oil cooler lines (on the transmission side).

Cause: 

Damaged o-rings due to unfavorable cooling line connection tolerances.

Procedure: 

Verify that the transmission fluid leak originates from the cooling lines area.

If so, replace the o-rings and the cooling lines.

Only replacing the o-rings may cause a repeat failure.