700R4 / 200-4R, Elevated Pressure Regulator Spring.
SONNAX 77917-08 (1 SPRING)
#4X. 700R4 / 200-4R, Elevated Pressure Regulator Spring. This replacement spring is stronger than many alternatives, and allows increased pressures throughout the stroking action of the pressure regulator valve. Low spring rates, incorrect spring heights and inappropriate replacements from previous rebuilds can lead to low base line pressure.