8L90 Master Rebuild Kit 2015, new and ready to install. Fits the 8L90. Ships fast from the USA.
When an 8L90 has slipped, overheated or filled the pan with clutch material, resealing it is not enough; every clutch pack needs fresh frictions and steels. This master rebuild kit is built for the GM 8L90 eight-speed from the 2015 model year on, the transmission behind the 5.3L, 6.2L and supercharged V8s in Silverado and Sierra 1500, Tahoe, Suburban, Yukon, Escalade, Camaro and Corvette. It is the one-box answer for a shop or a serious DIY builder who already has the unit on the bench.
From the kit photo, it carries a deep-pan filter, the pan gasket, front and rear seals, case and housing gaskets, the valve body separator plate gaskets, the O-ring and lip-seal assortment, and sets of frictions and steels for the clutch packs. GM's specification sheet describes the 8L90 as four gear sets and five clutches. Hard parts such as drums, the pump, planetaries, bushings and bonded pistons are not shown and should be checked and bought separately.
Rule out the cheap fixes first. GM Service Bulletin 18-NA-355 traces the 25 to 80 mph shudder on these trucks to fluid, cured by a full flush to Mobil 1 Synthetic LV ATF HP, so shudder alone is not a reason to rebuild. Sonnax also reports 8L90 valve bodies with line pressure above 415 psi against a design peak of about 315 psi, which burns clutches fast; if you rebuild without addressing that, the new frictions will not last. Our 8L90 rebuild guide to known wear points lists what to inspect, and 8L90 rebuild cost helps you weigh a rebuild against a replacement unit.
This kit is listed for all 8L90 units from 2015 on. GM did revise internal parts during production: GEARS Magazine documents different 2-3-4-6-8 clutch pistons for 2015-2017 and 2018-up units with changed seal grooves, and Transmission Digest covers the October 2015 removal of the #7 check ball. Read the RPO code and build date on your case, compare the kit against your old parts as you lay it out, and send us your year and VIN if you are unsure. The 8L45 is a different, lighter unit and does not take this kit. Browse every 8L90 part in our 8L90 collection.
| Fits | 8L90 2015 |
| Part type | Master Rebuild Kit |
| Condition | New |
| 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.
It is listed for all 8L90 units from 2015 on. GM changed some pistons and seal grooves for 2018-up, so lay the seals out against your old parts and send us your year and VIN if anything does not match.
No. The 8L45 is a lighter-duty eight-speed with different clutch packs. Check our 8L90 and 8L45 collection for 8L45 parts.
Not that we can confirm from the kit contents. Plan to inspect and source drums, bushings, the pump and pistons separately if they are worn.
Use a DEXRON HP licensed fluid such as Mobil 1 Synthetic LV ATF HP. GM lists 7.4 quarts for a drain and refill; a fully dry rebuilt unit takes more, so set the final level at temperature.
Usually you do not need to. GM bulletin 18-NA-355 cures most 8L90 shudder with a fluid flush. Rebuild when the unit slips, flares or has burnt clutch material in the pan.
