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  • Clutch failure
  • Solenoid performance codes
  • Wrong gear starts


Excess bore wear at AFL (actuator feed limit—GM) or solenoid pressure regulator (Ford) bore allows pressure loss that causes driveability concerns.


Recover hydraulic control and renew shift operation by reconditioning the bore and installing Sonnax oversized AFL/solenoid pressure regulator valve.

6F50, 6F55, 6T70 (Gen. 1), 6T75 (Gen. 1)

Oversized AFL/Solenoid Pressure Regulator Valve
Part No. 124740-01

You need this if... View Instructions

In Ford 6F50/55 and first generation GM 6T70/75 units, AFL/solenoid pressure regulator bore wear results in low pressure at the shift and control solenoid valve assembly. The OE valve has a large reaction area and is highly affected by side loading, which wears the valve body bore. As the bore wear increases, oil pressure is reduced to the shift solenoids, which causes solenoid and ratio codes. This also results in lower line pressure.

Sonnax oversized AFL/solenoid pressure regulator valve 124740-01 is a solenoid feed regulator valve that feeds the control solenoid valve assembly. The valve will restore hydraulic control to the shift solenoids.

  • Valve is hardcoat anodized to reduce 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 6T70 (Gen. 1), 6T75 (Gen. 1) Valve Body Layout

Gm 6t70 6t75 vbl

November 06, 2014

Ford 6F50, 6F55 Vacuum Test Guide

Topics: Vacuum Test Guides Vacuum Testing Transmission Ford 6F55 Transmission 6F50 Transmission

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  • 124740 01 combo
  • 124740 01

You need this if...

A vacuum test at the port indicated fails to hold at least 18 in-Hg

  • 124740 01 test