The rear oil seal of the engine crankshaft is leaking.

Refer to Crankshaft Rear Oil Seal Replacement in 7.4L Engine Mechanical.

The metal-cased, lip-type seal at the front of the input charging pump is leaking.

Replace the pump seal.

The seal around the outer diameter of the oil pump is leaking.

Replace the outer diameter pump seal.

The cranked weld in the torque converter assembly is leaking.

Repair or replace the converter assembly.

The torque converter pump hub at the seal area is worn.

Replace the torque converter pump hub.