P1811 code or a slip/shudder condition can indicate a pressure control problem in the GM 4T65-E. A worn or sticking torque signal regulator valve and bore reduces or prevents line rise, resulting in long soft shifts and slippage. Reconditioning the bore and installing Sonnax oversized torque signal valve 84754-44 restores proper hydraulic clearances and function of the torque signal oil circuit.

• Salvages valve bodies with worn torque signal bore and/or sticking valve
• Corrects P1811 code, slip/shudder condition and intermittent no/poor line rise