4L80E 4L85E Transmission Sonnax Actuator Feed Limit Valve Kit The actuator feed limit (AFL) valve in GM 4L80-E units has a large reaction area and is greatly affected by side loading, which wears the valve body bore. The EPC solenoid oscillates the torque signal and AFL oil, which increases valve action and accelerates wear. As bore wear increases, oil pressure is reduced to the shift solenoids, which causes solenoid and ratio codes. The same AFL oil loss results in lower line pressure. Installing the Sonnax AFL valve kit 34200-16K corrects AFL oil pressure loss, restoring shift solenoid pressure to prevent wrong gear starts and other shift concerns. The hard-coat anodized valve is extremely wear resistant, and annular grooves have been added to minimize the effect of side loading. The Sonnax wear-resistant sleeve provides more valve contact area, providing additional support and further reducing valve and bore wear. Kit includes wear-resistant sleeve and anodized valve with annular grooves to prevent side loading Valve operates in full-contact sleeve, providing 54% more support Boosts oil pressure to the shift solenoids Eliminates AFL oil loss, corrects low line pressure Note: Sonnax Tool 77754-TL is required to install this part!