Mercedes 722.9 transmissions may exhibit line pressure and converter-related problems due to excess wear in the working pressure regulator bore. Deterioration between the line and sump ports allows fluid loss that results in reduced lube flow and low line pressure. Wear at the balance end can cause high line pressure and harsh shifting. Reconditioning the bore and installing Sonnax oversized working pressure regulator valve 88740-01 restores hydraulic integrity for revived line pressure in all ranges.
Sonnax valve body layouts provide a detailed overview of individual units making it quick and easy to determine what’s available for the specific valve body you’re working on. See all Sonnax valve body layouts.
Vacuum testing at the port(s) indicated fails to hold the recommended minimum in-Hg, or if wear is visually detected.