Ford 6F50, 6F55 and first generation GM 6T70, 6T75 transmissions may exhibit multiple line pressure and converter-related problems due to excess wear in the main pressure regulator bore. Wear at the balance spool end allows critical fluid loss, resulting in excess line pressure, harsh shifts and overheating due to reduced cooler/converter flow. Wear at the outboard spool robs converter feed pressure and lowers line pressure, resulting in soft shifts and burnt clutches. Reconditioning the bore and installing Sonnax oversized pressure regulator valve kit 124740-12K restores hydraulic integrity for proper line pressure control in all ranges.

• Oversized pressure regulator valve and matched spring restore OE function
• Extended valve land for better sealing
• Hardcoat anodized aluminum valve combats premature wear