Cause:
Continuous oscillation of the pressure regulator valve causes valve body wear, resulting in line pressure irregularities and valve instability.
Correction:
Sonnax oversized main pressure regulator and boost valve kit allows line pressure function and control to be restored.
Toyota/Lexus A750, A760, A960 and AB60 series transmissions may exhibit multiple line pressure-related problems due to excessive wear in the main pressure regulator bore. Wear at the inboard regulating spool allows critical line pressure fluid to cross leak into the sump circuit, resulting in excess pressure and reduced cooler/converter flow. Sleeve wear at the reverse boost valve creates excessively high line pressure. Sleeve wear at the cutback valve allows oil loss resulting in poor line rise and burnt clutches. The Sonnax oversized main pressure regulator and boost valve kit allows the bore to be refurbished, and the hydraulic integrity restored for proper line pressure in all ranges.
Pressure regulator valve is made from high-quality, hardened steel to resist wear
Inner spool has annular groove to reduce side loading that causes wear
Kit includes an increased ratio boost valve assembly specially designed to work with the oversized regulator valve
Symptoms:
Cause: Continuous oscillation of the pressure regulator valve causes valve body wear, resulting in line pressure irregularities and valve instability.
Correction: Sonnax oversized main pressure regulator and boost valve kit allows line pressure function and control to be restored.
Toyota/Lexus A750, A760, A960 and AB60 series transmissions may exhibit multiple line pressure-related problems due to excessive wear in the main pressure regulator bore. Wear at the inboard regulating spool allows critical line pressure fluid to cross leak into the sump circuit, resulting in excess pressure and reduced cooler/converter flow. Sleeve wear at the reverse boost valve creates excessively high line pressure. Sleeve wear at the cutback valve allows oil loss resulting in poor line rise and burnt clutches. The Sonnax oversized main pressure regulator and boost valve kit allows the bore to be refurbished, and the hydraulic integrity restored for proper line pressure in all ranges.
Content:
SONNAX Installation Instructions