Fluid Leakage in Torque Converter Area

In diagnosing and correcting fluid leaks in the torque converter area, use the following procedures to locate the exact cause of the leakage. Leakage at the front of the transaxle, as evidenced by fluid around the torque converter housing, may have several sources. By careful observation it is possible, in many instances, to pinpoint the source of the leak before removing the transaxle from the vehicle. The paths which the fluid takes to reach the bottom of the torque converter housing are shown in the illustration. The 5 steps following correspond with the numbers in the illustration.

Fig 1: Identifying Fluid Leakage In Torque Converter Area

Courtesy of FORD MOTOR CO.

1. Fluid leaking by the converter hub seal lip will tend to move along the drive hub and onto the back of the torque converter. Except in the case of a total seal failure, fluid leakage by the lip of the seal will be deposited on the inside of the torque converter housing only, near the outside diameter of the housing.
2. Fluid leakage by the outside diameter of the converter hub seal and the case will follow the same path that leaks by the inside diameter of the converter hub seal follow.
3. Fluid leakage from the converter cover weld or the converter-to-flexplate stud weld will appear at the outside diameter of the torque converter on the back face of the flexplate and in the converter housing only near the flexplate. If a converter-to-flexplate stud or converter cover weld leak is suspected, install a new torque converter.
4. Fluid leaking from the pump cover, pump cover bolts or the torque converter hub seal inside the converter housing will flow down the back of the torque converter housing. Leakage may be from loose or missing pump cover bolts, defective pump cover seal or defective torque converter hub seal.
5. Engine oil leaks are sometimes incorrectly diagnosed as transaxle converter hub seal leaks. The following areas of possible leakage should also be checked to determine if engine oil leakage is causing the concern.
   1. Leakage at the valve cover gasket may allow oil to flow over the torque converter housing or seep down between the torque converter housing and cylinder block, causing oil to be present in or at the bottom of the torque converter housing.
   2. Oil galley plug leaks will allow oil to flow down the rear face of the cylinder block to the bottom of the torque converter housing.
   3. Leakage at the crankshaft rear oil seal will work back to the flexplate and then into the torque converter housing.
   4. Leakage at the oil pressure sensor.
   5. Cracks in the block.
   6. Leakage from the engine oil pan.