Symptoms:

  • Burnt clutches
  • Erratic line pressure
  • Low converter & lube flow
  • Overheating
  • Poor shift quality

Cause:

Continuous oscillation of the working pressure regulator valve results in excess bore wear, allowing line pressure to exhaust.

Correction:

Restore hydraulic integrity and renew line pressure performance by reconditioning the bore and installing Sonnax oversized working pressure regulator valve.

722.9

Oversized Working Pressure Regulator Valve
Part No. 88740-01

Replaces early and late-style OE valves.


You need this if... View Instructions Find a Distributor

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.

  • Hardcoat anodized aluminum valve combats premature wear
  • Lengthened critical spools for added stability and wear prevention
  • Annular grooves help center valve in bore to reduce future side-load wear

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.

Mercedes 722.9 Valve Body Layout

Mercedes 722.9 Valve Body Layout
  • 722.9 Oversized Working Pressure Regulator Valve 88740-01
  • 722.9 Oversized Working Pressure Regulator Valve 88740-01
  • 722.9 Oversized Working Pressure Regulator Valve 88740-01 details

You need this if...

Vacuum testing at the port(s) indicated fails to hold the recommended minimum in-Hg, or if wear is visually detected.

722.9 Oversized Working Pressure Regulator Valve Vacuum Test Locations