Leaky BMW trans
This TSB involves a transmission fluid leak at the oil pan area, specifically a leaking Mechatronic transmission O-ring leak on Model E53, E60, E63, E64, E65 and E66 with the ZF 6-speed 6HP19 or 6HP26 transmission.
Drain and save the long-term transmission fluid (Shell M-1375.4).
Replace the sealing sleeve (P/N 24 34 7 519 357) and the transmission oil pan gasket.
Be sure to push the sealing sleeve firmly into the housing assembly before closing the white locking tab of the Mechatronic. To ease sleeve installation, apply lubrication on both of the sleeve’s O-rings (using transmission fluid).
After installation, the correct distance between the transmission harness connector and the housing surface should not exceed 3 mm.
If the distance between the connector and the transmission housing measures approximately 7 to 8 mm, the sealing sleeve was installed incorrectly. If this is the case, an intermittent connection problem between the Mechatronic and the vehicle harness connector will occur, resulting in various EGS communication faults (e.g. FC 5079 “Serial wire message missing” or FC 507A “Serial line signal plausibility” or “Gearbox Emergency Program” light illumination (the transmission will enter a failsafe mode).
Clean the groove in the plastic oil pan before gasket installation. When reinstalling the oil pan, make sure that the sealing surface of the gasket is dry and free of oil.
If the sealing surface is not completely dry, the oil pan may still appear to exhibit a minor leak. Follow the torque sequence and specification from RA 24 34 020.
On vehicles equipped with a plastic oil pan (all with the exception of the E53), replace the drain plug.
Check and top-up the transmission fluid level using Shell M-1375.4 (P/N 83 22 0 142 516). Follow BMW’s filling procedure listed in the repair manual.
Warm the engine and test drive the vehicle to verify the repair.
In the unlikely event that the transmission fluid leak reappears in the area of the oil pan gasket after completion of the test drive, the transmission oil pan and gasket should be replaced.
P/N DESCRIPTION QUANTITY
24 34 7 519 357 Mechatronic sealing sleeve 1
24 11 7 571 204 6HP26 oil pan gasket (E60/61/63/64/65/66 1
24 11 7 543 484 6HP26 oil pan gasket (E53) 1
24 11 7 540 844 6HP19 oil pan gasket (all models) 1
24 11 7 520 713 Drain plug 6HP19/6HP26 (except E53) 1