Common problems associated with Toyota/Lexus U660E, U660F, U760E and U760F transmissions are overheating, TCC slip, TCC codes and converter failure. These issues can be caused by excess wear at the converter and lube relief check valves. This can cause the valve to leak fluid and significant wear can cause the valve to become stuck in the bore.
Reconditioning the bore and installing Sonnax oversized converter and lube relief check valve kit 47740-60K re-establishes correct clearance for proper converter and lube functions.
Vacuum testing at the port(s) indicated fails to hold the recommended minimum in-Hg, or if wear is visually detected.