Toyota A340E/F series transmissions may exhibit multiple line pressure and converter-related problems due to excessive wear in the main pressure regulator bore. Wear at the inboard balance spools allows critical line pressure fluid loss, resulting in excessively high pressure, harsh shifts and reduced cooler/converter flow. Wear at the outboard spools robs converter feed pressure and lowers line pressure, resulting in soft shifts and burnt clutches and brakes. The Sonnax oversized pressure regulator valve kit 97741-10K for type 3 and 4 units allows the bore to be refurbished and the hydraulic integrity restored for proper line pressure in all ranges. The improved and oversized Sonnax pressure regulator valve is also paired with a new and improved boost valve assembly to maintain the correct pressure curves and restore typically worn OE hydraulic clearances at the critical EPC, Reverse and cutback circuits within the assembly.

• Sleeve is made from high-quality aluminum to reduce wear
• Hardcoat anodized aluminum valves combat premature wear