4T65E

Symptoms:

• Erratic line pressure
• Maximum adapt
• Code 1811
• 2nd Gear starts
• Poor EPC control
• Long shifts
• TCC piston failure

Cause:
Actuator feed limit bore wear results in unregulated pressure at the EPC solenoid, 1-2, 3-4 shift solenoid and the 1-2, 3-4 shift signal circuit.

Correction:
This wear-resistant sleeve and valve assembly allows the salvage of the case cover by re-establishing hydraulic integrity of the AFL circuit.

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 restores hydraulic integrity to the AFL circuit.

• Highly wear-resistant aluminum sleeve provides more support and durability to prevent wear
• Wear-resistant, hard-anodized valve maintains proper clearance with thermal expansion
• Annular grooves center the valve to prevent wear
• Regulating pressure is reduced by about 10 psi to prevent high line pressure, which can lead to TCC piston damage

Contents:

• Sleeve
• Valve
• Regulating Spring
• Sleeve Retention Spring

SONNAX Installation Instructions