In Ford 10R60, 10R80 and 10R90 transmissions, the TCC regulator valve controls the application and release of the torque converter. The valve receives signal fluid that forces the valve to shuttle to its regulating position. In this position, the torque converter apply circuit is open to the secondary line and the torque converter release circuit is vented. This moves the converter into lockup state. Once the signal fluid is removed from the circuit, the TCC regulator valve returns to its install position where the torque converter apply circuit is disconnected from the secondary line and the torque converter release circuit is pressurized. This returns the converter to its released state.
Bore wear around the TCC regulator valve can negatively affect torque converter lockup. Bore wear around the valve can reduce converter apply flow, converter release flow and cooler flow. Boost sleeve wear can result in signal fluid loss and prevent the torque converter lockup.
Reconditioning the bore and installing the Sonnax oversized TCC regulator valve kit 105740-15K corrects the lockup issues along with restoring the proper hydraulic integrity of the circuit.
Vacuum testing at the port(s) indicated fails to hold the recommended minimum in-Hg, or if wear is visually detected.