10L1000 Transmission Filter and Metal-Core Pan Gasket Kit

The 10L1000 is the ten-speed Allison-branded unit behind the 6.6L Duramax in 2020 and newer Silverado 2500HD, 3500HD and Sierra HD trucks. It takes a service interval like any other automatic, and the filter and pan gasket are the two pieces you replace every time the pan comes down. This kit has both: the filter that replaces GM 24298004 (also sold as TF938) and the pan gasket that replaces 24297922.

The gasket in this kit is built on a metal core rather than being a plain molded rubber ring. That matters on this pan because the bolt pattern is long and the pan flange flexes; a bare rubber gasket can squeeze out at the corners and start a slow seep that shows up as a stain on the crossmember a month later. The steel carrier holds the sealing bead at a fixed crush height so the torque spec actually produces the clamp load it is supposed to.

On the bench the job is straightforward: drop the pan, pull the old filter straight down off its neck, wipe the pan and the case rail clean of the old gasket, seat the new filter until the seal is fully home, lay the new gasket on the pan rail, and torque the pan bolts in a crossing pattern to the factory spec. Refill with the correct Dexron ULV fluid and check level at the specified fluid temperature - this transmission is level-sensitive and will shudder if it is overfilled.