When the torque converter is defective, it would build unexpected pressures inside the torque converter, which could bring about tough idling. A further issue that can arise is tough idling. If your vehicle shudders or vibrates excessively even though idling, it may be a sign of a failing torque converter. https://waylonopnkf.ampblogs.com/the-basic-principles-of-torque-converter-clutch-70941985