8L90 Planetary, remanufactured and ready to install. Fits the 8L90. Ships fast from the USA.
This listing is a remanufactured GM 8L90 rotating clutch drum assembly supplied with its shaft, GM part number 24295113 (interchange 334555B). It is sold as the 2-8 and 4-8 Reverse drum, the housing for the 2-3-4-6-8 and 4-5-6-7-8-Reverse clutch packs, and its shaft carries 42-tooth splines that mate with the C3 side of the unit. Buyers looking for it usually have an 8L90 from a Silverado or Sierra 1500, Tahoe, Yukon or Escalade torn down with a cracked housing, a scored piston bore or a burned upper-gear pack, after the truck lost Reverse or started slipping from fourth gear up.
The 8L90 uses four planetary gear sets and five friction elements, named for the gears in which they apply. Transmission Digest's teardown of the unit shows how this drum's two clutches tie into the gear train: the ring gear of the front direct and overdrive gear set doubles as the 2-3-4-6-8 clutch hub, while a combined sun gear and input-carrier ring gear doubles as the 4-5-6-7-8-Reverse clutch hub. Between them those two clutches are applied in every forward gear except first and in Reverse. GM bulletin 16-NA-019 shows the 3-4 upshift applying the 4-5-6-7-8-Reverse clutch as the 1-3-5-6-7 clutch releases, which is why a leaking drum or a cracked piston shows up as a flared or neutral 3-4 shift before it gets worse.
A hydraulic or wiring fault can feel exactly like a failed drum. Sonnax documents a 3-4 neutral caused by swapped S8 and S9 solenoid connectors, and its field testing found worn 8L90 valve bodies producing over 415 psi of line pressure against a normal peak near 315 psi, enough to crack castings and shatter drums. Read codes, check fluid level and condition, and rule out the valve body before you commit to teardown. Our 8L90 3-4 clutch failure guide and 8L90 valve body testing guide lay out those checks. If high pressure broke the original drum, a replacement alone will fail again.
This assembly fits the GM 8L90 eight-speed only. It is not for the 6L80 or 6L90, and it is not for the lighter 8L45 or 8L50. Year matters more than it looks. GEARS Magazine reports that starting in 2018 GM revised the 2-3-4-6-8 clutch piston, dam piston, seal grooves and wave plate to stop piston cracking, and that early 2015-2017 seals and late 2018-up seals are not interchangeable. Match the 24295113 or 334555B number on your old drum, or send us your year and VIN, so the drum and the seal kit you build it with belong together. You can see every part for the unit on our 8L90 parts page.
| Fits | 8L90 |
| Part type | Planetary |
| Condition | Remanufactured |
| Brand | OEM |
| Ships | From the USA |
| Warranty | 1-year |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
No. Despite the product name, the item is the 2-8 and 4-8 Reverse clutch drum assembly with shaft, GM 24295113 (interchange 334555B). If you need a planetary carrier, see the 8L90 reaction planet listed for 2015-up.
No. It is built for the 8L90 only. The 8L45, 8L50, 6L80 and 6L90 use different drums.
It is the drum and shaft assembly. Plan on new piston seals and sealing rings for your model year, and fresh clutch plates if the packs were burned.
Cracked pistons on early units, which GM addressed with a 2018 piston and seal redesign, and excessive line pressure from a worn valve body. Check line pressure before you reinstall the transmission.
Yes. Run the fast learn and the clutch adaptive learns with a scan tool, then drive the truck through all eight gears so the control module adapts to the new parts.
