Shift Correction Kit

The Superior Transmission Parts K4F27E is a comprehensive shift correction kit engineered to significantly enhance the performance and reliability of Ford 4F27E, FN4A-EL, J39A, FNR5, and Mazda FS5A-EL automatic transmissions. This kit directly combats several prevalent transmission issues, including soft shifts and flairs, premature band failure, code P0741 (TCC slippage), and the commonly broken solenoid pressure regulator valve spring. It also addresses worn or damaged accumulator bores. By incorporating Superior's patent-pending billet 1-2 and neutral/drive dual sealing ring accumulator pistons and their patent-pending Accumulator Buddy brush, the kit allows for the reuse of previously discarded cases that would not have sealed properly due to wear. In addition to the advanced pistons and brush, the K4F27E kit features a new, stronger solenoid pressure regulator valve spring to replace the frequently failing stock component. The kit is provided with installation directions in English, complete with illustrations, to facilitate a correct and efficient repair process.