• Bump shifts
  • Flare shifts
  • Harsh shifts
  • Erratic shifts
  • Burnt clutches
  • Overheated fluid


Bore wear at control pressure regulator allows pressure loss that prevents proper clutch apply/release timing.


Recover hydraulic control and renew shift performance by installing Sonnax control pressure regulator valve kit.

6F35 (Gen. 1), 6F35 (Gen. 2)

Control Pressure Regulator Valve Kit
Part No. 144740-04K

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

Ford 6F35 Gen. 1 and Gen. 2 units incorporate a low-pressure compensator feed circuit to assist clutch return springs during release of Overdrive (4,5,6) and Direct (3,5,R) clutches. After clutches disengage, the compensator feed circuit maintains pressure in the clutch release cavity to oppose centrifugal application of the clutches.

Control over this process resides with the control pressure regulator valve. When the bore wears, correct valve operation is hindered, causing clutch apply timing issues such as harsh shifting, flares and bump shifts. In addition, overheated fluid and burnt clutches can result.

Installing Sonnax control pressure regulator valve kit 144740-04K restores normal compensator action, extending the service life of these units beyond that of the OE valve body casting.

  • Hardcoat anodized aluminum valve combats premature wear
  • Highly wear-resistant sleeve provides additional valve support
  • Includes a calibrated spring for restoring OE compensator pressure
  • Valve
  • Sleeve
  • Spring

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.

Ford 6F35 Valve Body Layout

Fd 6f35 vbl thumb
  • 144740 04k combo
  • 144740 04k

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.

  • 144740 04k test