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Symptoms:

  • Clutch failure
  • Band failure
  • Solenoid performance codes
  • Soft shifts & poor line rise
  • Harsh shifts
  • No 4th
  • 2nd Gear starts
  • Wrong gear starts

Cause:

Actuator feed limit bore wear results in low pressure at shift and EPC solenoids.

Correction:

This wear-resistant sleeve and hard anodized valve refurbish the bore to prevent AFL leakage while providing greater durability and thermal expansion properties.

4T80-E

AFL Valve Kit
Part No. 72854-01K


View Instructions

The OE actuator feed limit (AFL) valve routes regulated line pressure to the pressure control and shift solenoids. AFL pressure feeds the pressure control solenoid, which regulates the outgoing torque signal pressure. AFL pressure is directed to the shift solenoids to oppose spring force and stroke the shift valves. Constant oscillation of this hardened steel valve causes the cast aluminum bore to wear, reducing the AFL oil pressure, which can cause solenoid and ratio codes, clutch/band failure and harsh shifts. Bore wear can also cause the valve to stick in the exhaust position, resulting in 2nd gear starts and low line pressure. The Sonnax kit 72854-01K re-establishes the hydraulic integrity of the circuit by eliminating and preventing wear in the AFL circuit.

  • Kit includes a highly wear-resistant aluminum sleeve to provide more durability.
  • Hard-coat anodized valve reduces wear and provides better leakage control during thermal expansion.
  • Valve spools have been lengthened to provide better stability and prevent leakage.
  • Annular grooves have been added to center the valve and prevent wear from side loading.
  • A regulating spring has also been added to fit into the lengthened valve and set the correct limiting pressure.

Sonnax reamer tool kit 72854-TL must be used to oversize the existing bore.

  • Sleeve
  • Valve
  • Regulating Spring
  • Retaining Spring
  • Sleeve Retaining Clip
  • 72854 01k combo
  • 72854 01k