Torque Converter Upgrade for Mercedes V12- Lock-Up Clutch UpgradeRENNtech Torque Converter Upgrade for Mercedes V8K Lock Up Clutch Upgrade. While slippage in the torque converter is important under acceleration, this slippage becomes a liability once cruising speed is achieved. The lock up clutch controls this slippage and creates a solid connection between the engine and transmission. If the load on the clutch is too much, slippage can occur leading to excessive heat and wear. The RENNtech lock up clutch upgrade