Possible causes of oil leakage in automatic transmission:
Seals and gaskets:
* Worn or damaged shaft seals, drive flanges, and crankcase may leak oil.
Oil seals:
* Torque converter seals and front and rear transmission seals can wear out and leak oil.
Piping and hoses:
* Cracks or leaks in transmission coolant lines, power steering lines, or vacuum pump hoses can cause oil leakage.
Oil pan plug:
* An improperly tightened or damaged oil pan plug may allow oil to leak.
Torque converter:
* Cracks or damage to the torque converter housing may cause oil leakage.
Shaft rings:
* Worn or damaged O-rings on transmission shafts can cause oil leakage.
Sponge seals:
* Sponge seals between automatic transmission components can become worn or damaged, causing oil leakage.
Ventilation hole:
* A clogged vent can cause excessive pressure in the automatic transmission, causing oil to leak from weak points.
Other possible reasons:
* Automatic transmission overfilled with oil
* Improper installation or tightening of automatic transmission components
*External transmission damage