10L80, 10L90

Symptoms:

• Momentary wheel lockup
• Code P0747
• Downshift to 2nd from high gear
• Harsh shifts
• 5th Gear only
• Reduced propulsion message
• Burnt clutches
• Clutch failure
• Safety Recall N242480630 Momentary Wheel Lock-Up
• Safety Recall N242454440 Momentary Rear Wheel Lock-Up

Cause:
Severe side-load wear in the feed limit low valve reduces pressure to the default disable solenoid, putting the vehicle into default or power loss mode.

Correction:
Installing drop-in Sonnax feed limit low valve kit overcomes bore wear, restoring proper valve function and preventing future wear.

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, then triggers a check engine light and reduced propulsion message 10,000 miles before failure. Vehicles are then limited to 5th Gear, commonly referred to as limp mode, until the valve body is serviced to address the failed valve.

The Sonnax patented, drop-in feed limit low valve kit overcomes bore wear, restoring proper valve function immediately 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, while upgraded materials prevent future wear.

• Overcomes drivability issues related to the GM 10-speed wheel lockup recall
• Patented valve and sleeve combination overcomes bore wear and significantly reduces future side loading of the valve
• Hardcoat anodized aluminum valve and wear-resistant sleeve combat premature wear
• Drop-in Zip Valve™ parts install quickly and easily

Note: 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.

Contains:

• Valve
• Sleeve
• Spring
• Retainer
• Drill Not Shown
• Rivet Not Shown

129787K Instruction Sheet

Sonnax Feed Limit Low Valve Kit – 105740-54K