Mechanical reasons:
* Wear or failure of friction discs
* Worn or damaged bearings
* Damage to turbine or pump wheel
* Biting the torque converter locking mechanism
*Damage to torque converter housing
Hydraulic reasons:
*Low or contaminated transmission fluid
* Damage to the torque converter pump
* Malfunction of valves or solenoids that control the torque converter
*Leaks in torque converter seals
Electrical reasons:
* Malfunction of torque converter speed sensor
* Damage to the wiring harness supplying the torque converter
*Transmission control module (TCM) malfunction
Other reasons:
*Overheating due to insufficient cooling or excessive load
*Excessive vibration or stress due to engine or transmission failure
* Aging and corrosion of torque converter components
* Foreign objects entering the torque converter