6L90 Overhaul Kit, new and ready to install. Fits the 6L90. Ships fast from the USA.
When a 6L90 in a Silverado or Sierra 2500HD/3500HD, an Express or Savana van, or a performance car has burned clutches and is coming out for a full rebuild, this kit covers the soft parts and the known-weakness fixes in one box. It is a new 6L90 overhaul package built for a builder who wants the unit to leave the bench stronger than it left the factory, not just resealed. It is aimed at heavy-duty trucks that tow and the vans that run all day loaded.
Steel plates are not included; reuse good steels or ask us for a set. The Sonnax boost valve shown in some photos is not included because the TransGo kit supplies its own booster.
The 6L90 is clutch-to-clutch: five clutches, all applied by oil that travels from the pump, through the valve body and stator support, into drums sealed by rings and bonded pistons. A tired seal does not just drip, it bleeds apply pressure off a clutch so it fills slowly and slips. The upgrades here target the weak points: the HD pump slide spring helps the pump hold volume during line rise and at high RPM, the clutch select valve springs address a P0751 tendency on mid-2010 and earlier units, and the center support seals stop cross-leaks that starve the 1-2-3-4, 3-5-R and 4-5-6 clutches.
A worn valve body, a twisted cooler line or a weak pump can mimic tired clutches, and a rebuild will not fix those. Run a hot line pressure test, read codes and look in the pan first. Our 6L90 pump failure guide covers pressure testing, and 6L90 common problems and fixes lists the bulletins worth ruling out.
Built for the 6L90 (RPO MYD), the heavy-duty six-speed GM used from 2007 in HD pickups, full-size vans and the high-output Camaro and Corvette. No year range is printed on this kit, so treat it as a general 6L90 kit. Do not swap in 6L80 frictions: the 6L90 4-5-6 housing takes seven friction plates where the 6L80 takes six, and several hubs and housings differ in height. Check the RPO code on the glovebox label or send us your year and VIN. If you want a kit with steels instead of the upgrade parts, see the 6L90 overhaul kit for 2007-up, and browse the 6L90 parts page for hard parts.
| Fits | 6L90 |
| Part type | Overhaul Kit |
| Condition | New |
| Brand | GM |
| Ships | From the USA |
| Warranty | 1-year |
Doing this repair right usually means replacing these at the same time. Same transmission, ships together.
No. It includes the full friction set but not steels. Reuse steels that are flat and not blued, or ask us to quote a steel set.
It is built for the 6L90. The 6L90 uses seven frictions in the 4-5-6 clutch versus six in the 6L80, and several drums and hubs are different heights, so the friction count will not match a 6L80.
The TransGo kit corrects line rise and clutch apply weaknesses that wear clutches on heavy-duty units. Installing it during the rebuild is cheaper than pulling the valve body later.
Yes. Clear the adaptive values and run the service fast learn with a scan tool, then drive it unloaded before towing so the controller can settle its shift adapts.
Dexron VI. GM bulletins specify it for the 6L80 and 6L90, and worn-out fluid is a documented cause of shudder.
