8L90 Clutch Drum 2020, used and ready to install. Fits the 8L90. Ships fast from the USA.
This is a used GM 8L90 1-3-5-6-7 clutch drum supplied with its input shaft, part number 24278844, listed for 2020 and later units. GM calls this pack C3, and it is the clutch applied when you shift from Neutral into Drive, so a leaking drum shows up first as a slow or harsh Drive engagement and then as slipping in first, third, fifth, sixth and seventh. It is aimed at late 8L90 owners, mostly full-size Silverado and Sierra 1500 pickups, whose teardown found a cracked drum, worn bushing or seal journals, damaged input shaft splines, or a C3 pack that will not hold air.
The input shaft takes turbine torque from the converter and drives this drum directly, so the drum is always turning at input speed. GM bulletin 16-NA-019 shows C3 applying on the 2-3 and 4-5 upshifts and releasing on the 1-2, 3-4 and 7-8 upshifts, and GM uses C3 for the Neutral-to-Drive garage shift learn. Apply oil reaches the piston through sealing rings on the shaft and stator support, which is why worn ring lands on the shaft cause the same complaint as a worn drum. Buying the drum and shaft together removes the spline fit and the shaft journals as variables.
Follow GM bulletin 20-NA-187: let the vehicle sit 8 to 24 hours, shift into Drive and watch input speed. If it takes longer than 3 seconds to reach zero, run the 20-shift C3 learn. GM only calls for teardown and inspection of the 1-3-5-6-7 clutch if the learn fails. Also rule out pressure problems; Sonnax measured worn valve bodies running above 415 psi against a normal 315 psi peak and tied that runaway pressure to shattered drums. Our 8L90 valve body guide and pump failure guide cover those checks. If the drum failed from high pressure, a new drum alone will fail again.
This assembly is listed for 2020 and later 8L90 units. Two details decide whether it fits yours. GEARS Magazine reports this drum was built in a four-clutch version (code 8L90A) and a five-clutch version (8L90B), identified by the code next to the QR code on top of the drum, with the choice depending on application and year. The input shaft also comes in two styles: a standard shaft with a stator bushing journal, and a longer shaft without that journal for centrifugal pendulum absorber converters used with Dynamic Fuel Management and diesel. These cannot be mixed. Match the drum code, the shaft style and part number 24278844, or send us your year and VIN. It does not fit the 8L45. Earlier units can use the 8L90 input drum listing, and every part for this family is on the 8L90 collection page.
| Fits | 8L90 2020 |
| Part type | Clutch 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.
Yes. It is the 1-3-5-6-7 clutch drum together with its input shaft, part number 24278844.
It is listed for 2020 and later. Drum clutch count and input shaft style vary by application, so match the drum code and shaft or send your year and VIN.
Units with a centrifugal pendulum absorber converter use a longer input shaft without the stator bushing journal. Standard units use a shaft with the journal. They are not interchangeable.
Possibly. Use GM's 3-second input speed test and run the C3 learn first. GM only calls for inspecting the 1-3-5-6-7 clutch if the learn does not fix it.
No. The 8L45 uses its own smaller drums. This assembly is for the 8L90 only.
DEXRON HP only. GM TechLink lists 7.4 quarts for a service refill on current applications, but capacity varies by vehicle and a rebuilt unit needs more.
