March 16, 2016
Toyota/Lexus vehicles equipped with U341E and U341F units may have TCC apply and release concerns such as no lockup, slipping lockup or TCC stuck on. Improper lockup can result in harsh downshifts or engine stall at idle as well as associated trouble codes. On vehicles equipped with a lockup control valve train, bore wear allows control pressure to escape the circuit. Reconditioning the bore and installing Sonnax oversized lockup control valve kit 37740-08K renews TCC operation by restoring critical clearances and preventing pressure loss.
Not all U341E and U341F units have a lockup clutch control valve train. Verify this valve train is present prior to ordering kit. Units that do not contain this valve train will have an empty bore.
Sonnax valve body layouts provide a detailed overview of individual units making it quick and easy to determine what’s available for the specific valve body you’re working on. See all Sonnax valve body layouts.
Vacuum testing at the port(s) indicated fails to hold the recommended minimum in-Hg, or if wear is visually detected.