8L90 Input Drum 2020, used and ready to install. Fits the 8L90. Ships fast from the USA.
If you are searching for an 8L90 input shaft, GM part number 24278844, for a 2020 or newer Silverado 1500, Sierra 1500, Tahoe, Yukon or Escalade, this is the assembly: a used input shaft that comes already joined to the 1-3-5-6-7 clutch drum. Shops usually reach for it after a teardown turns up chewed shaft splines, scored sealing ring lands, a worn converter-end journal, or a drum that leaks down on the air test. Owners see it as a slow or clunky shift into Drive, slipping in odd gears, or a flare on the 2-3 shift.
Everything the engine sends through the converter turbine enters the gearbox through this shaft, and the 1-3-5-6-7 drum on its end spins with it at all times. Fluid for the clutch piston in that drum travels through drilled passages in the shaft and is held in by sealing rings, so a shaft with worn ring grooves bleeds apply pressure exactly like a cracked drum would. GM's adaptive bulletin 16-NA-019 charts this clutch applying on the 2-3 and 4-5 upshifts, and bulletin 20-NA-187 uses it for the Neutral-to-Drive engagement learn, which is why one tired assembly can upset garage shifts and several upshifts at once.
Start with the cheap steps. GM 20-NA-187 has you park the vehicle 8 to 24 hours, select Drive and time how long input speed takes to drop; past 3 seconds, run the engagement learn before condemning anything. Then check line pressure. Sonnax found worn 8L90 valve bodies peaking above 415 psi against a normal figure near 315 psi, and that excess pressure is known to crack drums. Our 8L90 common problems guide walks through both, and the 3-4 clutch failure guide helps separate a drum leak from a C5 or solenoid harness fault. Only after the unit is apart can you judge the shaft splines, ring lands and drum casting directly.
This piece is listed for 2020 and later 8L90 transmissions. Two late-model variations matter here. First, GEARS Magazine notes that gas engines with Dynamic Fuel Management and diesel models use a centrifugal pendulum converter with a longer input shaft that has no stator bushing journal, while standard units use a shorter shaft with that journal; the two cannot be swapped and you cannot convert a stator to suit. Second, the attached drum is built in four-clutch (code 8L90A) and five-clutch (8L90B) versions, marked next to the QR code on top of the drum. Hold your old shaft next to the photos, match 24278844 and the drum code, or send us your year and VIN and we will check it. For 2015-2019 rebuilds, look at our 8L90 input drum for earlier units, and browse the full 8L90 parts collection for the rest of the job. It is not an 8L45 part.
| Fits | 8L90 2020 |
| Part type | Input Drum |
| Condition | Used |
| Brand | OEM |
| Reference | 24278844 |
| Ships | From the USA |
| Warranty | 1-year |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
This listing is the input shaft and 1-3-5-6-7 clutch drum together as one assembly under reference 24278844, so you are not fitting a separate shaft into a separate drum.
Possibly, but do not assume it. Shaft length depends on whether the truck has a CPA converter, and drum clutch count depends on application. Compare it to your old part or send us your year and VIN.
Look at the converter end. The CPA shaft is longer and has a polished tip with no stator bushing journal. The standard shaft has a land where the stator bushing rides.
No. The frictions, steels and sealing rings in a used assembly are not guaranteed. Install new plates and rings that match the drum's four or five clutch count.
Yes. Clear the transmission adaptives, run GM's Neutral-to-Drive engagement learn, then drive through all shifts so the controller relearns clutch fill times.
DEXRON HP. Mobil 1 LV ATF HP is the fluid named in GM's shudder bulletin. Fill to the level check procedure at operating temperature rather than by a fixed quart count.
