September 30, 2005
Anatomy of a Transmission: Oil Flow in the Pump-PR-Converter-Cooler Lube Circuits
Gregg Nader
The OE actuator feed limit (AFL) valve routes regulated line pressure to the pressure control solenoid and the 1-2, 3-4 shift signal circuit in GM 4T65-E units. Wear at the AFL valve bore can cause low torque signal and/or low 1-2, 3-4 shift solenoid and shift signal circuit pressure, resulting in Code 1811, maximum adapt or long shift, TCC slippage and wrong gear starts. Bore wear also can cause poor EPC control, leading to high line pressure and TCC piston damage. The Sonnax AFL valve and sleeve kit 84596-02K restores hydraulic integrity to the AFL circuit.
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.
September 30, 2005
Gregg Nader
March 21, 2013
A vacuum test at AFL port fails to hold 18 in-Hg of vacuum or higher, or a wet air test (WAT) at the AFL port produces excessive leakage from the two locations indicated.