Symptoms:

  • No 4th
  • No 5th
  • No 6th
  • Low clutch oil pressure
  • Harsh shifts
  • Flare shifts

Cause:

Excess actuator feed limit (AFL) bore wear allows pressure loss that leads to driveability concerns.

Correction:

Recover hydraulic control and renew shift performance by reconditioning the bore and installing Sonnax oversized AFL valve.

6T30 (Gen. 1), 6T30 (Gen. 2), 6T31 (Gen. 3 6T40), 6T35 (Gen. 3 6T40), 6T40 (Gen. 1), 6T40 (Gen. 2), 6T41 (Gen. 3 6T40), 6T45 (Gen. 2), 6T45 (Gen.1), 6T46 (Gen. 3 6T40), 6T50 (Gen. 1), 6T50 (Gen. 2), 6T51 (Gen. 3 6T40)

Oversized Actuator Feed Limit Valve
Part No. 144740-01


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

The function of the actuator feed limit (AFL) valve is to provide regulated pressure to shift solenoids. Wear in the AFL bore causes low clutch pressure and results in transmission slips/harsh shifts. This eventually leads to a loss of 4th through 6th Gears, and finally the loss of transmission function. Reconditioning the bore and installing Sonnax oversized AFL valve 144740-01 restores hydraulic control for revived shift operation in all ranges for 6T30/40/45/50 (Gen. 1 and 2) and 6T35/31/41/46/51 (Gen. 3 6T40) units.

  • Hardcoat anodized aluminum valve combats premature wear
  • 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.

GM Gen. 1 6T40, 6T45, 6T50 Valve Body Layout

GM Gen. 1 6T40, 6T45, 6T50 Valve Body Layout

GM Gen. 2 6T30/40/45/50, Gen. 3 6T40 Valve Body Layout

GM Gen. 2 6T30/40/45/50, Gen. 3 6T40 Valve Body Layout
  • 6T30 (Gen. 1), 6T30 (Gen. 2), 6T31 (Gen. 3 6T40), 6T35 (Gen. 3 6T40), 6T40 (Gen. 1), 6T40 (Gen. 2), 6T41 (Gen. 3 6T40), 6T45 (Gen. 2), 6T45 (Gen.1), 6T46 (Gen. 3 6T40), 6T50 (Gen. 1), 6T50 (Gen. 2), 6T51 (Gen. 3 6T40) Oversized Actuator Feed Limit Valve 144740-01
  • 6T30 (Gen. 1), 6T30 (Gen. 2), 6T31 (Gen. 3 6T40), 6T35 (Gen. 3 6T40), 6T40 (Gen. 1), 6T40 (Gen. 2), 6T41 (Gen. 3 6T40), 6T45 (Gen. 2), 6T45 (Gen.1), 6T46 (Gen. 3 6T40), 6T50 (Gen. 1), 6T50 (Gen. 2), 6T51 (Gen. 3 6T40) Oversized Actuator Feed Limit Valve 144740-01
  • 6T30 (Gen. 1), 6T30 (Gen. 2), 6T31 (Gen. 3 6T40), 6T35 (Gen. 3 6T40), 6T40 (Gen. 1), 6T40 (Gen. 2), 6T41 (Gen. 3 6T40), 6T45 (Gen. 2), 6T45 (Gen.1), 6T46 (Gen. 3 6T40), 6T50 (Gen. 1), 6T50 (Gen. 2), 6T51 (Gen. 3 6T40) Oversized Actuator Feed Limit Valve 144740-01

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.

6T30 (Gen. 1), 6T30 (Gen. 2), 6T31 (Gen. 3 6T40), 6T35 (Gen. 3 6T40), 6T40 (Gen. 1), 6T40 (Gen. 2), 6T41 (Gen. 3 6T40), 6T45 (Gen. 2), 6T45 (Gen.1), 6T46 (Gen. 3 6T40), 6T50 (Gen. 1), 6T50 (Gen. 2), 6T51 (Gen. 3 6T40) Oversized Actuator Feed Limit Valve Vacuum Test Locations
6T30 (Gen. 1), 6T30 (Gen. 2), 6T31 (Gen. 3 6T40), 6T35 (Gen. 3 6T40), 6T40 (Gen. 1), 6T40 (Gen. 2), 6T41 (Gen. 3 6T40), 6T45 (Gen. 2), 6T45 (Gen.1), 6T46 (Gen. 3 6T40), 6T50 (Gen. 1), 6T50 (Gen. 2), 6T51 (Gen. 3 6T40) Oversized Actuator Feed Limit Valve Vacuum Test Locations