How do you know if your torque converter is having troubles?
a common problem is shuddering when you accelerate. as in not smooth acceleration. some might confuse it with a vibration which can point to driveline issues such as rear driveshaft imbalance issues which is possible with an AWD car like yours.
a vibration issue can be a motor issue that is mixed in with a trans link? the motor provides power to the trans which is output to the driveline.
worn u-joints? bad carrier bearing? bad cv joints? motor mounts? trans mounts? vs motor issues. engine misfire means not smooth acceleration. any check engine lights?