8L90 Clutch Module, new and ready to install. Fits the 8L90. Ships fast from the USA.
This is the Raybestos RGPZ-019 GPZ friction clutch pack module for the GM 8L90, the heavy-duty eight-speed behind the 5.3L and 6.2L V8s in 2015 and later Silverado, Sierra, Tahoe, Yukon, Escalade, Corvette and Camaro SS. It is a full set of friction discs for all five clutches, built with Raybestos GPZ high-energy lining. If your 8L90 is slipping on a group of shifts, flaring between gears while towing, or the pan came off full of black fluid and lining debris, this is the friction side of the rebuild.
The 8L90 has no bands. Five multi-plate clutches, each covering several gears, are applied in combinations to make eight forward ratios and reverse. Raybestos names them by the ranges they work in: C1 (1, 2, 7, 8, Reverse), C2 (1, 2, 3, 4, 5, Reverse), C3 (1, 3, 5, 6, 7), C4 (2, 3, 4, 6, 8) and C5 (4, 5, 6, 7, 8, Reverse). Every shift releases one clutch while another applies, so a pack with tired lining slips during the overlap and makes more heat every time. GPZ is the Raybestos lining built for that heat: the company describes it as a blend of high-energy fibers for stress and high temperature durability and recommends it for heavy-duty, commercial and high-stress use, which describes a lot of 8L90 trucks pulling trailers.
Twenty friction discs in total. Steels, seals and the filter are not included.
The 8L90 is famous for shift and shudder complaints that are not burnt clutches. GM's shudder bulletin traces many trucks to fluid and the converter clutch, Sonnax documents high line pressure from worn valve body bores, and a swapped solenoid connector can drop 4th gear. Work through our 8L90 common problems guide and the 3-4 clutch failure guide first. If the fluid is burnt and lining is in the pan, the frictions need replacing and this module is the right part.
Raybestos catalogs RGPZ-019 for the GM 8L90 from 2015 on. It does not fit the smaller 8L45, which takes a different friction set. Within the 8L90 there are year changes to watch: GEARS Magazine reports the C5 discs moved from radial to spiral grooves for 2019 along with a calibration change, and the 1-3-5-6-7 drum comes in four-clutch (8L90A) and five-clutch (8L90B) versions marked next to the QR code. Count the discs you remove from each pack and match groove pattern and tooth count before assembly; send us your year and VIN if anything differs. More parts for this unit are on the 8L90 and 8L45 collection page.
| Fits | 8L90 |
| Part type | Clutch Module |
| Condition | New |
| Brand | Raybestos |
| Ships | From the USA |
| Warranty | 1-year |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
Frictions only. RGPZ-019 contains 20 GPZ friction discs across the five 8L90 clutches. Steels, seals, gaskets and the filter are bought separately.
GM put the 8L90 behind the larger V8s from 2015 on, including Silverado and Sierra 1500 with the 5.3L and 6.2L, Tahoe, Yukon, Escalade, Corvette and Camaro SS. Confirm the RPO on your glovebox label or send us your VIN.
Raybestos makes GPZ lining with high-energy fibers for heat and stress and recommends it for heavy-duty and high-stress driving, such as towing with a half-ton truck.
No. The 8L45 uses smaller clutches with different plate counts. Raybestos catalogs a separate friction module for it.
Refill with DEXRON HP, set the level hot, clear adaptive values and perform the fast learn with a scan tool, then road test through every gear so the module learns the new clutches.
Probably not by itself. GM bulletin 18-NA-355 ties that steady-speed shudder to the torque converter clutch and fluid, and calls for a fluid exchange. Rule that out before tearing the unit down.
