Front-Seal Blowout after Converter Replacement in 09D/T Transmissions
The Aisin AW TR-60SN/VW 09D/T transmissions are found in the 2002-2010 VW Touareg and the 2003-2010 Porsche Cayenne. There have been reports of the front seal blowing out after the torque converter and related parts have been replaced.
The root cause of the seal blowing out is the buildup of pressure because the drain-back passage that normally vents the area behind the front seal is blocked. This area is normally vented through the stator support/pump cover. The seal-blowout issue occurs when the pump (body and gears) is mated to an incorrect stator support (pump cover) and blocks the drain-back passage. To understand how easy it is to make this mismatch, you need to know the large number of possible combinations. Be aware that the seal-blowout problem is only one of several issues that you can create if you mismatch components.