In listed Toyota/Lexus units, the continuous oscillation of the secondary regulator valve wears the valve spools and valve body bore at the contacting surfaces. Such wear results in TCC pressure irregularities and valve instability. If pressure is high, harsh lockup clutch engagement can result. If the pressure is too low, the TC clutch cannot achieve complete lockup. Continuous clutch slippage will lead to burned clutch material and converter. Under these conditions loss of mileage and poor drive-ability are to be expected. Reconditioning the bore and installing Sonnax oversized secondary pressure regulator valve kit 57917E-16K restores proper hydraulic function.

• Hardcoat anodized aluminum valve combats premature wear
• Oversized valve and included matched spring restore OE regulated pressure specifications
• Kit allows salvage of previously non-repairable valve bodies and avoids searching for, and purchase of, expensive replacement valve bodies