Ford CD4E and Mazda LA4A-EL transmissions frequently exhibit symptoms of lube failure, harsh shifts and line pressure instability. Wear of the pressure regulator balance circuit (opposite end from spring) creates high line pressure. High line pressure is known to break up parts, but also positions the valve to reduce the flow into converter/cooler circuits. If the vehicle goes into failsafe (no EPC control) the lube circuit can be shut off completely on the OE valve. The OE converter regulator valve shuts off cooler/converter flow at 90-100 psi.

Sonnax oversized pressure regulator and converter regulator valve kit 73840-RK featires a converter regulator valve and PR valve which work together to limit converter pressure, yet ensure flow continues during a failsafe condition.

• Updated valves flow a safe regulated pressure into both the line and converter circuit, yet maintain control under low pump volume and high line conditions
• Improved line-to-lube circuit allows full-time cooler flow
• Includes an EPC pressure limit relief valve
• Redesigned converter regulator valve has a lengthened spool to eliminate cooler pressure loss
• Tapered spool design of the converter regulator valve ensures flow at extreme pressure
• Hardcoat anodized aluminum valves combat premature wear and feature annular grooves to prevent side loading