Tech tip: Correctly installing a turbine shaft seal
The early model Fichtel and Sachs single clutch ZF converters and the late model Fichtel and Sachs captive clutch ZF converters both use the same radial lip seal to seal the turbine shaft. The seal is located in the turbine hub in the early model single clutch converters and in the cover in the late model captive clutch converters. The lip side of the seal faces the impeller in both converters. There has been some confusion when the seals are being installed. When the seal is installed into the turbine hub, the metal clad side of the seal faces the installer, but when the seal is installed into the cover the lip side of the seal faces the installer. The early single clutch and late model clutch pack type Toyota converters have a similar problem. The seal in the early single clutch Toyota converters is in the turbine hub and the lip faces the impeller like the ZF converters, but in the late model clutch pack Toyota converters the TCC piston and clutch pack are located in the cover and the lip side of the seal faces the cover. The main purpose of the turbine shaft seal is to seal the TCC apply circuit. In all single clutch, multi clutch, and captive clutch converters the apply oil enters the converter from the impeller side so the lip side of the seal will face the impeller for those applications. In all clutch-pack converters the apply oil exits the turbine shaft and enters the converter between the piston and cover so the lip side of the seal faces the cover. Remember that the force of the apply oil helps the lip of the seal to do its job. If the seal is installed backwards the lip acts like a one way valve and opens to exhaust the oil. Exhausting the oil causes a decrease in apply pressure which will set a TCC slip code.
– Found in November 2008 Newsletter