October 26, 2017
In Toyota/Lexus U760E and U760F units, the steel OE solenoid modulator valve is prone to side-loading in the bore. This side-loading action, combined with repeated oscillation of the valve, prematurely wears the cast aluminum bore. The result is line pressure leakage and excess SL, SLT and SLU solenoid pressure which floods the solenoids and creates shift quality concerns, solenoid codes and deviation of proper control pressures available to various valves.
Sonnax drop-in solenoid modulator valve kit 47740-42K allows you to recondition the bore and install improved components to restore normal solenoid supply pressures. This sleeve/valve assembly provides a new and unworn bore for hydraulic sealing of the valve while the sleeve seals off existing moderate bore wear to prevent fluid loss. A new spring and selective shims allows for resetting of the correct limit pressure.
Vacuum testing at the port(s) indicated fails to hold the recommended minimum in-Hg, or if wear is visually detected.
Note: Due to the design changes on the Sonnax sleeve and valve, post-install vacuum testing at the inboard port is not a valid sealing test.