GM 6L45 6L50 6L80 6L90 Sonnax Pressure Regulator Valve Kit GM 6L45, 6L50, 6L80 and 6L90 units may exhibit multiple line pressure and cooler/converter/lube flow problems due to excess wear in the pressure regulator bore. Deterioration at the balance spool end allows critical fluid loss, resulting in high 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. Installing Sonnax pressure regulator valve kit 104520-14K restores the hydraulic integrity of these circuits for proper line pressure control in all ranges. Hardcoat anodized aluminum valve combats premature wear Lengthened critical spools operate in non-worn portion of bore for added stability and wear prevention. Annular grooves help center valve in bore to reduce future side-load wear No reaming or special tools required Note: Pump must be removed to install kit. Contents Valve Drill Bit Checkballs (2) 1 Extra