May 16, 2025
Understanding the ’19-Later GM 10-Speed Safety Recall
Jim Dial
The feed limit low valve in listed GM transmissions limits line pressure feed to the default disable solenoid and control valves. Feed limit low pressure is also connected to the boost ball system for "A" and "B" clutch control.
This feed limit low valve is subject to significant side-load force, resulting in severe wear and pressure loss to the default disable solenoid and connected control valves. This pressure loss can put the vehicle into default mode at high speeds, resulting in momentary wheel lockup, sudden downshift to 2nd Gear, harsh shifts, or a P0747 code. The feed limit low valve can wear out in as little as 30,000 miles, with many vehicles requiring service by 35,000 miles.
A national recall from GM includes installing updated software that monitors valve performance and wear, triggers a check engine light and reduced propulsion message 10,000 miles before failure, indicating the valve body should be replaced. Vehicles are then limited to 5th Gear, commonly referred to as limp mode, until the valve body is serviced to address the failed valve.
Sonnax patented, oversized feed limit low valve kit 105740-59K overcomes bore wear, restores proper valve function without the need or expense of replacing the entire valve body. The valve reroutes the balance circuit through an internal passage, significantly reducing the side-load force, and upgraded materials prevents future wear.
The OE feed limit low and high valves are at high risk for premature wear and failure. Replace both valves in every build even if there are no transmission problems and the valves pass a vacuum test.
You can use the F-124740-TL48 with the VB-FIX or you can use the 144740-TL bench tool kit if you do not have the VB-FIX.
May 16, 2025
Jim Dial
Vacuum testing at the port(s) indicated fails to hold the recommended minimum in-Hg, or if wear is visually detected.

