GM Gen. 1 6T30/40/45/50 transmissions may exhibit multiple line pressure and converter-related problems due to high 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 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 144510-01K restores hydraulic integrity for proper line pressure control in all ranges.

• Oversized pressure regulator valve and matched spring restore OE function
• Hardcoat anodized aluminum valve combats premature wear
• Annular grooves help center valve in bore to reduce future side-load wear