4L80E/4L85E Shift Solenoid Kit A & B - 24230289 24230288

This is the A and B shift solenoid pair for the GM 4L80E and 4L85E four-speed automatic, replacing AC Delco part numbers 24230289 and 24230288. The two normally-open on-off solenoids bolt to the valve body, and the PCM switches them in combination to route line pressure for the 1-2 and 2-3 shift changes. Selling them as a matched pair is how most techs replace them, since both age at the same rate.

Fitment covers 4L80E and 4L85E units behind GM trucks and vans - Chevrolet Silverado 2500 and 3500, Suburban, Tahoe, Express 2500, GMC Sierra and Savana, and similar 1991-up heavy-duty applications. Before ordering, drop the pan and check that your existing solenoids carry 24230289 and 24230288 so you know you have the electrical on-off style and not a PWM unit.

When one of these solenoids sticks or fails electrically you will usually see a harsh or missing 1-2 or 2-3 shift, the transmission hung in a single gear or limp mode, and a check-engine light with a code such as P0753 (shift solenoid A electrical) or P0758 (shift solenoid B electrical). Both are reached by dropping the pan and pulling the filter, so there is no full teardown to swap them.

On the bench, unbolt the old solenoids from the valve body, fit fresh O-rings, seat the new units squarely, and torque the retaining bolts to spec. Reinstall the filter and pan with a new gasket, refill with the correct Dexron fluid, and cycle the gears to confirm clean 1-2 and 2-3 engagement before road testing.