Symptoms:

  • Shift quality is not load sensitive
  • Harsh shifts
  • Slips & flares
  • Delayed engagement
  • Burnt clutches
  • Slide shifts
  • Slip codes

Cause:

Wear in clutch boost/latch valve bores causes feedback pressure instability, preventing normal shift operation.

Correction:

Recover hydraulic control and renew shift performance by reconditioning the bore and installing Sonnax oversized clutch boost/latch valve.

6F50, 6F55, 6T70 (Gen. 1), 6T75 (Gen. 1)

Oversized Clutch Boost/Latch Valve
Part No. 144740-23

Fits any of three locations.


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

Ford 6F50/55 and first generation GM 6T70/75 clutch boost/latch valves provide feedback pressure to their respective clutch regulator valves, balancing the regulators to assist with apply and release of the associated clutch. Pressure control solenoid fluid acts on the boost/latch valve to precisely control the amount of oil delivered to the balance end of the clutch regulator valve.

Excess wear in boost/latch valve bores can result in harsh shifts, slipping, burnt clutches, flares, and delayed engagement. Reconditioning the bore and installing Sonnax oversized clutch boost/latch valve 144740-23 restores the hydraulic control necessary for trouble-free shifting.

  • Hardcoat anodized aluminum valve combats premature wear
  • Oversized valve engineered to perform to OE specification

Proper operation of clutch boost/latch valves depends on correct pressure being supplied by shift solenoids. If trouble is found with pressure supply to these solenoids, Sonnax offers oversized AFL/solenoid regulator valve 124740-01.

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 6F50, 6F55 Valve Body Layout

Ford 6F50, 6F55 Valve Body Layout

GM 6T70/75 (Gen. 1) Valve Body Layout

GM 6T70/75 (Gen. 1) Valve Body Layout
  • 6F50, 6F55, 6T70 (Gen. 1), 6T75 (Gen. 1) Oversized Clutch Boost/Latch Valve 144740-23
  • 6F50, 6F55, 6T70 (Gen. 1), 6T75 (Gen. 1) Oversized Clutch Boost/Latch Valve 144740-23

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.

6F50, 6F55, 6T70 (Gen. 1), 6T75 (Gen. 1) Oversized Clutch Boost/Latch Valve Vacuum Test Locations
6F50, 6F55, 6T70 (Gen. 1), 6T75 (Gen. 1) Oversized Clutch Boost/Latch Valve Vacuum Test Locations