8L90 Valve Body Solenoid Kit, 7-Piece GM 8-Speed

This is the full seven-solenoid set for the GM 8L90 valve body, the eight-speed Hydra-Matic that sits behind the 5.3L and 6.2L truck engines and the LT1 cars. The kit carries GM references 24272278, 24272280, 24272281 and 24272282, and the same solenoids are used in the lighter-duty 8L45 and 8L50 valve bodies. Listed fitment is Silverado 1500 and Sierra 1500 2015-up, Colorado and Canyon 2015-up (not the 2.8L diesel), Yukon, Yukon XL, Escalade and Escalade ESV 2015-2017, Camaro 2016-2019, Corvette 2015-2019, Cadillac ATS and CTS 2016-2019, CT6 2016-2018, XT4 2019, CT4 2020-2021, Malibu XL 2.0T and Equinox 2.0T 2016-2019, Buick LaCrosse and Envision 2.0T, and Express and Savana 2017-up with the 2.8L diesel.

The 8L90 does not usually fail mechanically first. It fails at the solenoids. Heat and miles change how the pressure control solenoids meter, and the truck starts banging the 1-2, flaring on the 4-5, cycling the converter clutch at light throttle, or dropping into limp and holding fourth. A scan tool will normally hang the code on one circuit, but every solenoid in that valve body has the same hours and the same fluid history on it, so replacing a single one usually buys a few months before the next code sets. That is why the whole set goes in at once.

On the bench: drop the pan, pull the filter, unplug the internal harness, and unbolt the valve body. The solenoids are retained by small clips or brackets on the valve body casting. Pull one at a time and set the new one in the same bore, since the solenoids in an 8L90 are not all interchangeable position to position. Lubricate the O-rings with clean fluid before they go in, seat each solenoid fully so the connector tab lines up with the harness, and torque the valve body bolts in sequence. Refill with DEXRON HP or the GM-specified fluid and set level by temperature, not by dipstick guess, because the 8L90 is sensitive to fill level.

Condition note from the source: these are aftermarket solenoids, unused, supplied without the original retail box. Surface marks from handling are normal and do not affect function.